new Ecotec problem.....happens when I accelerate briskly...

[maverick1]

Toby, had your fuel tank rubber gaskets deteriorated and plugged up your fuel filter and pump, or was it something else?

Back to my problems.
I just got back from test driving the car and it once again went into "Limp" mode (and no I don't need Viagra) and the accelerator stopped working.
I plugged in a code reader and pulled out more codes than James Bond on a new mission.
Here they are.
P0101
P0230
P0502
P0650
P2122
P2128
Hopefully nothing too serious.

[Terry Kennedy]

I plugged in a code reader and pulled out more codes than James Bond on a new mission.
Here they are.
P0101

MAF/SCIP/TP airflow out of range. On an Atom, loose MAF connector/dirty MAF sensor/old-style intake. Shouldn't set limp mode.

P0230

Fuel pump - caused by immobilizer. "Normal". Doesn't set limp mode.

P0502

Vehicle speed sensor low voltage. Not normal. Mis-aligned sensor at transmission, loose wire, or PCM. Shouldn't set limp mode.

P0650

Check engine light inoperational. "Normal". Doesn't set limp mode.

P2122

Accelerator Pedal Position sensor 1 low voltage detected. Not normal. Sets limp mode. Bad APP module (on gas pedal), loose wire, or PCM.

P2128

Accelerator Pedal Position sensor 2 high voltage detected. Not normal. Sets limp mode. Bad APP module (on gas pedal), loose wire, or PCM.

All of these happened in the brief period since you re-connected the emergency disconnect switch?

Given that 3 of them are voltage-related, I'd check the battery connections, loose fuses or relays (particularly the PCM relay), and the small push-on wires on the bottom of the emergency disconnect switch (pull off, squeeze connectors carefully w/ pliers, re-connect).

If that doesn't do it, spray the MAF with MAF cleaner (only!), make sure its plug is on snugly, and replace the gas pedal (part number and pic earlier in the thread).

Let me know if you or your mechanic needs the fault flow diagrams for these codes.

[silver]

FWIW mine used to throw codes I think it was P2101 and P0068, they constantly threw my car into limp mode, so I had them removed from the tune (technically not removed but can't go into limp mode)


I was hoping you might be throwing those codes, so you'd at least know they were nothing...sorry.

[maverick1]

I plugged in a code reader and pulled out more codes than James Bond on a new mission.
Here they are.
P0101

MAF/SCIP/TP airflow out of range. On an Atom, loose MAF connector/dirty MAF sensor/old-style intake. Shouldn't set limp mode.

P0230

Fuel pump - caused by immobilizer. "Normal". Doesn't set limp mode.

P0502

Vehicle speed sensor low voltage. Not normal. Mis-aligned sensor at transmission, loose wire, or PCM. Shouldn't set limp mode.

P0650

Check engine light inoperational. "Normal". Doesn't set limp mode.

P2122

Accelerator Pedal Position sensor 1 low voltage detected. Not normal. Sets limp mode. Bad APP module (on gas pedal), loose wire, or PCM.

P2128

Accelerator Pedal Position sensor 2 high voltage detected. Not normal. Sets limp mode. Bad APP module (on gas pedal), loose wire, or PCM.

All of these happened in the brief period since you re-connected the emergency disconnect switch?

Given that 3 of them are voltage-related, I'd check the battery connections, loose fuses or relays (particularly the PCM relay), and the small push-on wires on the bottom of the emergency disconnect switch (pull off, squeeze connectors carefully w/ pliers, re-connect).

If that doesn't do it, spray the MAF with MAF cleaner (only!), make sure its plug is on snugly, and replace the gas pedal (part number and pic earlier in the thread).

Let me know if you or your mechanic needs the fault flow diagrams for these codes.

Thanks Terry and Silver, don't know what I'd do without the help from this forum.
I will check all the battery connections, fuses and relays.
Can you please let me know what the PCM relay is....a pic would be great.

[Terry Kennedy]

[quote="maverick1"]
Can you please let me know what the PCM relay is....a pic would be great.[/quote]

It is one of the relays under the fuse box covers in the nose. They're all interchangeable, so just shuffle 'em.

Edit: Un-broke the quote tag

[positron]

Any recent engine modifications and/or who's tune on who's ECM is it?

[maverick1]

[quote="Positron"]
Any recent engine modifications and/or who's tune on who's ECM is it?
[/quote]
No recent mods. Still using the original Brammo tune.
Actually I just picked up a new ECU and was planning on going to the tuner in the next week or so.
Now I don't think I can go to the tuner until I get this accelerator issue solved.

[positron]

Unless you have a mud in the pedal problem, your exceeding the standard Cobalt airflow which exceeds the "we don't want to be Toyota out of control gas pedal safety intervention protocol" parameter.

Ask your tuner to add 10-15% to the max VE table to compensate for the smaller pulley therefore greater airflow. If he/she gives you the "whuu?" look tell them you'll be back when they do.

This also assumes you've verified the "Silver" check the throttle body connector procedure." (no slam intended just procedure nomenclature) This will manifest itself generally at throttle run up but caused by high g or agitation/disruption caused by previous.

also this was done on a spirited throttle run up and not just a lazy run up.

My beer says TOCGPSIP.

[toby]

>>Toby, had your fuel tank rubber gaskets deteriorated and plugged up your fuel filter and pump, or was it something else?

Yep. pump completely fouled. Looked at it today. Debris in the tank and in the pump. And the little straining socks had deteriorated. The tank is out of the car getting a good scrubbing. New everthing going back in today. Have you replaced your gaskets?

Sounds like your problem might be something else. These forum gurus have you on the right track, methinks.

[maverick1]

[quote="Positron"]
Unless you have a mud in the pedal problem, your exceeding the standard Cobalt airflow which exceeds the "we don't want to be Toyota out of control gas pedal safety intervention protocol" parameter.

Ask your tuner to add 10-15% to the max VE table to compensate for the smaller pulley therefore greater airflow. If he/she gives you the "whuu?" look tell them you'll be back when they do.

This also assumes you've verified the "Silver" check the throttle body connector procedure." (no slam intended just procedure nomenclature) This will manifest itself generally at throttle run up but caused by high g or agitation/disruption caused by previous.

also this was done on a spirited throttle run up and not just a lazy run up.

My beer says TOCGPSIP.
[/quote]
Does anyone have a pic of this throttle body connector, or at least where it's located?
thanks

[positron]

Invisible post...

[silver]

reach behind the throttle body from underneath, you'll feel it, tug towards the front of the car, not down to remove the sensor.

you can't fit a camera in there, the only way you'd see it, is if you removed the firewall then it's easy to see.

[maverick1]

thanks silver, I found the plug and it was very secure.
Well I just finished doing everything from checking all the wiring, the fuses, battery connections, removed and cleaned the MAF, cleaned and installed the air filter, and went out again for a drive and got the following codes.

P2138
P2122
P2128
P0650
Looks like it must be the accelerator pedal assembly #22731157 so I just ordered one.
Looks like a difficult area to work in.
If only I had a contortionist as a friend....Peter.
I tell you I would much rather have an old fashioned throttle cable instead of this electronic piece of crap.
I have a 21 year old Toyota Camry which has the good old throttle cable and have never had a problem with it in 21 years.
I called the local GM dealer and he gave me the price and said that they don't have it in stock, that it is on back order.
Back order....I guess this means that many of these accelerator pedal sensors are going crap in lots of cars for it to be on back order.
Does not surprise me....I regret not going with the Honda motor even though it was around $5,000 more.
I owned a 1988 Honda Civic hatchback....man it was my best car I've ever owner. Got it up to over 530,000kms before I retired it in 2007. Great little car.

[Terry Kennedy]

[quote="maverick1"]
Looks like a difficult area to work in.
If only I had a contortionist as a friend....Peter.[/quote]

It isn't actually that bad - I change mine regularly

[Bruce Fielding]

It's only a potentiometer. Does it have to be GM?