CB1100 Idle speed instability problem

[SportsterDoc]

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

I'd expect that cleaning electrical connections may have been the "cure".
To evaluate a battery, check voltage key off, key on and while cranking.

1. KEY OFF battery voltage, at the battery: Normal is 12.8, acceptable is 12.6 (standard lead acid battery, not AGM) to 12.8 for no load. If just taken off a charger, voltage may be 13 point something. The battery needs to sit for a while before a reading is useful. In the case of a bad cell, the other cells overcharge and give an almost normal reading, until load is applied.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell

2. KEY ON battery voltage (headlight on): Normal is not under about 12.5 initially, but will decline the longer that the headlight is on, without the motor running. Under no load, 12.5 volts indicates 50% discharge, but under load, it is just voltage drop.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance

3. KEY ON battery voltage while cranking: Normal is not under 10.5 volts
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance or
• Starter is drawing too much current

4. If the bike is running, battery voltage at about 2,500 RPMs should be 13.8 to 14.8
• If not, then check stator resistance and regulator ground
• If the stator is not shorted to ground and resistance is within spec, the regulator or regulator ground is suspect

Nonetheless, glad that you solved it.

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

Dang it! I knew I shouldn't have traded-in my CB. : )

I have "moved on" with my Street Twin, but I haven't lost curiosity for what will become of this issue. I have the ST for less than two weeks and it's a nice bike, but I can't help but feel that it will be "bait" for a new CB somewhere down the line.

Glad to hear your problem has stayed away!

Yep, and you may have solved it! But you did give several reasons for trading it. There, feel better?!

How are you liking the Street Twin?

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.

[peterbaron]

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

I'd expect that cleaning electrical connections may have been the "cure".
To evaluate a battery, check voltage key off, key on and while cranking.

1. KEY OFF battery voltage, at the battery: Normal is 12.8, acceptable is 12.6 (standard lead acid battery, not AGM) to 12.8 for no load. If just taken off a charger, voltage may be 13 point something. The battery needs to sit for a while before a reading is useful. In the case of a bad cell, the other cells overcharge and give an almost normal reading, until load is applied.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell

2. KEY ON battery voltage (headlight on): Normal is not under about 12.5 initially, but will decline the longer that the headlight is on, without the motor running. Under no load, 12.5 volts indicates 50% discharge, but under load, it is just voltage drop.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance

3. KEY ON battery voltage while cranking: Normal is not under 10.5 volts
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance or
• Starter is drawing too much current

4. If the bike is running, battery voltage at about 2,500 RPMs should be 13.8 to 14.8
• If not, then check stator resistance and regulator ground
• If the stator is not shorted to ground and resistance is within spec, the regulator or regulator ground is suspect

Nonetheless, glad that you solved it.

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

Dang it! I knew I shouldn't have traded-in my CB. : )

I have "moved on" with my Street Twin, but I haven't lost curiosity for what will become of this issue. I have the ST for less than two weeks and it's a nice bike, but I can't help but feel that it will be "bait" for a new CB somewhere down the line.

Glad to hear your problem has stayed away!

Yep, and you may have solved it! But you did give several reasons for trading it. There, feel better?!

How are you liking the Street Twin?

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.
....and if I can add something::: ignition OFF

when both terminals DISCONNECTED from the battery, join disconnected NEGATIVE and POSITIVE CABLES!! (NOT battery!! ) together for 15 min, prior reconnecting'em back to the battery terminals....

pb

p. s. Good work SportsterDoc

[pdedse]

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

I'd expect that cleaning electrical connections may have been the "cure".
To evaluate a battery, check voltage key off, key on and while cranking.

1. KEY OFF battery voltage, at the battery: Normal is 12.8, acceptable is 12.6 (standard lead acid battery, not AGM) to 12.8 for no load. If just taken off a charger, voltage may be 13 point something. The battery needs to sit for a while before a reading is useful. In the case of a bad cell, the other cells overcharge and give an almost normal reading, until load is applied.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell

2. KEY ON battery voltage (headlight on): Normal is not under about 12.5 initially, but will decline the longer that the headlight is on, without the motor running. Under no load, 12.5 volts indicates 50% discharge, but under load, it is just voltage drop.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance

3. KEY ON battery voltage while cranking: Normal is not under 10.5 volts
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance or
• Starter is drawing too much current

4. If the bike is running, battery voltage at about 2,500 RPMs should be 13.8 to 14.8
• If not, then check stator resistance and regulator ground
• If the stator is not shorted to ground and resistance is within spec, the regulator or regulator ground is suspect

Nonetheless, glad that you solved it.

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

Dang it! I knew I shouldn't have traded-in my CB. : )

I have "moved on" with my Street Twin, but I haven't lost curiosity for what will become of this issue. I have the ST for less than two weeks and it's a nice bike, but I can't help but feel that it will be "bait" for a new CB somewhere down the line.

Glad to hear your problem has stayed away!

Yep, and you may have solved it! But you did give several reasons for trading it. There, feel better?!

How are you liking the Street Twin?

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.
....and if I can add something::: ignition OFF

when both terminals DISCONNECTED from the battery, join disconnected NEGATIVE and POSITIVE CABLES!! (NOT battery!! ) together for 15 min, prior reconnecting'em back to the battery terminals....

pb

p. s. Good work SportsterDoc

What does this do?

[Lord Popgun]

Allows capacitors to discharge.

[pdedse]

Allows capacitors to discharge.

Sorry, not good with "electrics"...what's the effect of doing so? Does it allow something to reset? Longer battery life? Give a better reading when tested?

[peterbaron]

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

I'd expect that cleaning electrical connections may have been the "cure".
To evaluate a battery, check voltage key off, key on and while cranking.

1. KEY OFF battery voltage, at the battery: Normal is 12.8, acceptable is 12.6 (standard lead acid battery, not AGM) to 12.8 for no load. If just taken off a charger, voltage may be 13 point something. The battery needs to sit for a while before a reading is useful. In the case of a bad cell, the other cells overcharge and give an almost normal reading, until load is applied.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell

2. KEY ON battery voltage (headlight on): Normal is not under about 12.5 initially, but will decline the longer that the headlight is on, without the motor running. Under no load, 12.5 volts indicates 50% discharge, but under load, it is just voltage drop.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance

3. KEY ON battery voltage while cranking: Normal is not under 10.5 volts
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance or
• Starter is drawing too much current

4. If the bike is running, battery voltage at about 2,500 RPMs should be 13.8 to 14.8
• If not, then check stator resistance and regulator ground
• If the stator is not shorted to ground and resistance is within spec, the regulator or regulator ground is suspect

Nonetheless, glad that you solved it.

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

Dang it! I knew I shouldn't have traded-in my CB. : )

I have "moved on" with my Street Twin, but I haven't lost curiosity for what will become of this issue. I have the ST for less than two weeks and it's a nice bike, but I can't help but feel that it will be "bait" for a new CB somewhere down the line.

Glad to hear your problem has stayed away!

Yep, and you may have solved it! But you did give several reasons for trading it. There, feel better?!

How are you liking the Street Twin?

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.
....and if I can add something::: ignition OFF

when both terminals DISCONNECTED from the battery, join disconnected NEGATIVE and POSITIVE CABLES!! (NOT battery!! ) together for 15 min, prior reconnecting'em back to the battery terminals....

pb

p. s. Good work SportsterDoc

What does this do?

What does this do?

I do NOT want to interfere/mess with SportsterDoc & Co fantastic and hard work on diagnostic procedures at all...

Exceptionally, I will answer your question pdedse:


"By touching both battery CABLES together you may clear ELO/MIL and also reset residual ECM/ECU values ( electrical issues your vehicle may have).

Touching the battery CABLES together for longer time resets CEL's on your vehicle.
ECM/ECU stores all DTC in its memory so even if your battery goes dead there will still be a CEL when you start it back up.... and one of a way to get rid of a CEL or any other warning light is to clear the codes and fix the underlying problem.

By resetting computer , you will NOT fix your problems

ELO/MIL is a warning that a sensor/component has sent a signal to the ECM that it is out of specs and should be checked/repaired/replaced.
If you checked and repaired the problem, it is necessary to erase DTC if the engine light stays on. The best way to do this would be with a scanner, but if you don’t have one, disconnecting the battery will do the trick on many vehicles. However, disconnecting the battery will not only erase DTC's but also erase learnt drivability, +++ more issues (like radio code) in many vehicles. Registered your DTC before disconnecting the battery.

Allow 15 minutes ( some sources say no less than 5 min.) for the diagnostic information to be erased. FIRST, install the positive cable and THEN the negative one.

Following these steps is necessary for any drivability learn procedures on your vehicle. Many vehicles will go through these procedures automatically, if you drive for about 30 min. However, you may have a very low idle, or sometimes stalling, until the system learns.
The ECM/ECU/PCM has now learned where the throttle should be when in the closed position. Different vehicles will have different procedures".

ELO = Engine Light ON = MIL = Malfunction Illumination Light ( DTC is set, history or active)
ECM = Electronic Control Module = ECU = Electronic Control Unit
DTC = Diagnostic Trouble Code

Hope this GENERAL info is sufficient for you and others = non automotive oriented members.


pb

[SportsterDoc]

Peter, good addition. Forum members can also reference page 5-14 of the FSM on stored DTC resetting by shorting the DLC.

For those not familiar with capacitors (condenser is an old term), most dry capacitors are wound layers of foil and paper insulation which store a charge.

Most of us oldsters are aware of capacitors used for a points type ignition;
typically 0.22 microfarad units.

When points open, voltage charges the capacitor, to save burning the points during contact separation. When points close, the capacitor discharges into the coil to accelerate coil energization. If the capacitor is not to spec, points will pit on one side and build material on the other.

When I operated an electric motor rewind shop, we had meters for measuring capacitors, but for starting capacitors, we'd just energize, through a resistor (avoid a dead short), remove the lead, then short the terminals with a screw driver. Some sparks and a sharp "snap" and it was considered good. That could be done on some running capacitors, also.

Large capacitor banks are used at power stations to offset VARS from resistance loads.

For their use in electronic circuits, Popgun or Max or others with electronic backgrounds would answer better than I...other than I am aware that their storage capacity allows memory of station presets in modern automotive radios.

[pdedse]

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

I'd expect that cleaning electrical connections may have been the "cure".
To evaluate a battery, check voltage key off, key on and while cranking.

1. KEY OFF battery voltage, at the battery: Normal is 12.8, acceptable is 12.6 (standard lead acid battery, not AGM) to 12.8 for no load. If just taken off a charger, voltage may be 13 point something. The battery needs to sit for a while before a reading is useful. In the case of a bad cell, the other cells overcharge and give an almost normal reading, until load is applied.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell

2. KEY ON battery voltage (headlight on): Normal is not under about 12.5 initially, but will decline the longer that the headlight is on, without the motor running. Under no load, 12.5 volts indicates 50% discharge, but under load, it is just voltage drop.
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance

3. KEY ON battery voltage while cranking: Normal is not under 10.5 volts
• If lower, then battery is discharged and needs charging or
• Battery has a bad cell or
• Battery cable(s) have high resistance or
• Starter is drawing too much current

4. If the bike is running, battery voltage at about 2,500 RPMs should be 13.8 to 14.8
• If not, then check stator resistance and regulator ground
• If the stator is not shorted to ground and resistance is within spec, the regulator or regulator ground is suspect

Nonetheless, glad that you solved it.

Hey guys, I experienced the Idle speed instability problem for a while but it was luckily solved. I bought my bike with 5k miles and it was only after the 16k miles mark when I started experiencing very low idle to the point that it stalled a few times. I tried several things trying to fix the problem, I adjusted valves, cleaned injectors, changed spark plugs, air filter, (among other services and inspections like disconnecting the power commander and resetting procedures) and nothing helped. I was about to give up and just accept that my bike was just another CB that suffered from this common disease. Then, while I was cleaning electrical connections, I remember that I was using a cheap battery from Autozone and decided to replace it with a motobatt battery. The cheap battery from Autozone was only a few months old, but one day when I was riding far from home, the stock battery decided to give up. I was 2 miles from autozone and it saved my life. I never suspected the reason for this problem could be the battery because it would start right up every time. I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.

Dang it! I knew I shouldn't have traded-in my CB. : )

I have "moved on" with my Street Twin, but I haven't lost curiosity for what will become of this issue. I have the ST for less than two weeks and it's a nice bike, but I can't help but feel that it will be "bait" for a new CB somewhere down the line.

Glad to hear your problem has stayed away!

Yep, and you may have solved it! But you did give several reasons for trading it. There, feel better?!

How are you liking the Street Twin?

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.

Max suggested (via email) that disconnecting the battery may have "reset" the ECM...so, more than one possibility.
....and if I can add something::: ignition OFF

when both terminals DISCONNECTED from the battery, join disconnected NEGATIVE and POSITIVE CABLES!! (NOT battery!! ) together for 15 min, prior reconnecting'em back to the battery terminals....

pb

p. s. Good work SportsterDoc

What does this do?

What does this do?

I do NOT want to interfere/mess with SportsterDoc & Co fantastic and hard work on diagnostic procedures at all...

Exceptionally, I will answer your question pdedse:


"By touching both battery CABLES together you may clear ELO/MIL and also reset residual ECM/ECU values ( electrical issues your vehicle may have).

Touching the battery CABLES together for longer time resets CEL's on your vehicle.
ECM/ECU stores all DTC in its memory so even if your battery goes dead there will still be a CEL when you start it back up.... and one of a way to get rid of a CEL or any other warning light is to clear the codes and fix the underlying problem.

By resetting computer , you will NOT fix your problems

ELO/MIL is a warning that a sensor/component has sent a signal to the ECM that it is out of specs and should be checked/repaired/replaced.
If you checked and repaired the problem, it is necessary to erase DTC if the engine light stays on. The best way to do this would be with a scanner, but if you don’t have one, disconnecting the battery will do the trick on many vehicles. However, disconnecting the battery will not only erase DTC's but also erase learnt drivability, +++ more issues (like radio code) in many vehicles. Registered your DTC before disconnecting the battery.

Allow 15 minutes ( some sources say no less than 5 min.) for the diagnostic information to be erased. FIRST, install the positive cable and THEN the negative one.

Following these steps is necessary for any drivability learn procedures on your vehicle. Many vehicles will go through these procedures automatically, if you drive for about 30 min. However, you may have a very low idle, or sometimes stalling, until the system learns.
The ECM/ECU/PCM has now learned where the throttle should be when in the closed position. Different vehicles will have different procedures".

ELO = Engine Light ON = MIL = Malfunction Illumination Light ( DTC is set, history or active)
ECM = Electronic Control Module = ECU = Electronic Control Unit
DTC = Diagnostic Trouble Code

Hope this GENERAL info is sufficient for you and others = non automotive oriented members.


pb

Thanks for taking the time to explain; it's always helpful to hear things laid out clearly. I do like learning!

[max]

Very well explained, Peter.
Inside the ecm is one or more micro controllers, they operate on 5 volts, which is derived from the 12 volt supply.
every supply has capacitors to stabilize the circuit very much like a battery does, and these capacitors keep charged up for some time until the electronic parts slowly drain the capacitors over time and the voltage drops below say 1 volt.
at that point some of the memory erases and goes back to a state when the Electronic Control Module thinks it is just installed on a new bike.

The reason for this is that it saves money and operator mistakes when some parts have to be calibrated for proper operation, some parts have a different value if installed on a bike and by having an automated calibration routine ( initialization learning cycle ) the bike learns new values for various sensors and replaces the preset data with the actual learned values ( voltages ).
so the software programmers wrote a routine to learn these new values on first switch-on.

On STARTUP ( when the fuel pump cycles ) the micro checks all sensors very quickly and also checks "learned data",
if no data is stored it thinks it is installed on a new bike and performs a learning cycle and writes things like minimum and maximum throttle position data into the initialization memory.
So if you change the battery the disconnect time is long enough for the ecm to reset to new and influences some learned ( good or otherwise ) behavior of the bike, sometimes that fixes a problem until the wrong data is re learned.

Some of the startup cycle shows up in the video, as i re connect the tps but the mil light is still on and it is not until i turn the key on, the ecm re checks the circuit and decides that the tps is ok again and stops blinking.
At that time the faultcode is still stored in memory for future diagnosis but not indicated because the voltage of the tps is measured by the ecm, found to be within preset specifications ( in this case 0.5 volt ) and no fault code is displayed through the orange mil light.
In my case the ecm does not go into "limp mode" ( 1200 rpm when cold ) but resumes normal behavior with the learned stored values and starts up with 1500 rpm, exept now the engine is warm so it reverts to 1050 rpm from 950 or so when in "limp mode" as the video shows, so there is a lot to be learned from disconnecting the tps.

max

[dave]

I had the battery tested and it was good, but maybe it was fact that it had lower specifications than those required by the cb1100 charging system and it was causing the low idle problem. I waited 3000 miles to report my problem/solution just to make sure the problem was solved. I know that my case can be an isolated case but hopefully it helps someone one day. cheers.
[/quote]

I replaced my original battery with a new, YUASA battery and it did not solve the idle issue.