Problems with ECM? - Toyota Nation Forum : Toyota Car and Truck Forums

dhansen · 01-05-2011, 11:52 PM

My son's 94 camry started having warm stalling issues, Cleaning out the intake seemed to remedy the situation for about a month but it's doing it again. Besides cleaning the intake, I've done the "remove the hose from the EGR trick" and have replaced the coolant temperature sensor. None of which has fixed the issue.

I finally was going to drop it of at a local mechanic and noticed the car wasn't shifting properly, it would never get out of second gear. Two years ago I had the transmission rebuilt so I don't think anything is wrong with the transmission. Could the ECM have gone bad? I'm wondering if this is why the transmission isn't shifting and why when the car is warm it sputters and stalls.

Any help you can provide is greatly appreciated!!

Lash70 · 01-06-2011, 01:45 AM

Check your transmission fluid level and condition, meaning color, and make sure it is still slippery and not brown. If it is in good condition then check your transmission temperature sensor or whatever it is referred to. If that fails it could tell the TCM (Transmission Control Module) that the transmission is overheating in which the TCM puts the transmission in "default" mode which means it only has first and second gear as a cool-down tactic because in first and second gears the transmission is at a slower RPM than the engine where as third and overdrive it is either at the same RPM in third and then faster RPM in overdrive. Also, any emissions defect can have an effect on how the transmission shifts and or doesn't shift.

***Mister_Perkins*** · 01-06-2011, 08:47 AM

check out the following link for rough idle:

5sfe IAC Removal (lots of pictures)

camry6 · 01-06-2011, 05:47 PM

Quote:

Originally Posted by dhansen

My son's 94 camry started having warm stalling issues, Cleaning out the intake seemed to remedy the situation for about a month but it's doing it again. Besides cleaning the intake, I've done the "remove the hose from the EGR trick" and have replaced the coolant temperature sensor. None of which has fixed the issue.

I finally was going to drop it of at a local mechanic and noticed the car wasn't shifting properly, it would never get out of second gear. Two years ago I had the transmission rebuilt so I don't think anything is wrong with the transmission. Could the ECM have gone bad? I'm wondering if this is why the transmission isn't shifting and why when the car is warm it sputters and stalls.

Any help you can provide is greatly appreciated!!

Quite possible, ECMs have been known to cause weird ghost problems. Computers sometimes go bad.

***Mister_Perkins*** · 01-06-2011, 05:52 PM

Test the computer with the following image. If your values are not within spec, replace ECU with known good ECU and re-test. This will confirm a ECU > transmission problem. You may need to block the front tires off the ground to run these tests. Please securely jack / block the vehicle

dhansen · 01-12-2011, 11:27 PM

I removed the cable from negative battery post and let the car sit overnight. The next day I reattached and started it up. It ran for about 20 minutes and then I test drove it for about 45 minutes. The transmission was shifting better but it would'nt shift into third until it got up to 30,000 rpms then it would act like it was in neutral race up even further and then finally go into gear. It also went into overdrive just fine. After the 45 minute drive I parked the car in the driveway when it promptly sputtered and stalled. WTF?

Another thing I noticed is the car never seemed to warm up. The heater was barely blowing warm air (it was 10 degrees out at the time) and the gauge never moved from Cold. It's so strange that all of these things are happening at the same time? Anyone know how much an ECM runs from a junkyard? Not really sure if this is even the problem.

Thank you so much for your suggestions so far.

***fenixus*** · 01-12-2011, 11:39 PM

the temperature gauge you seeing on dash has nothing to do with ECM, it's just a sender unit, not a sensor monitored by ECU. however ECU has its own sensor for coolant temperature and acts accordingly when it's cold.

if you have no CEL on, it means problem is where ECM doesn't see it or treats its as irrelevant or "thinks" this is how it's supposed to be (a base for its adjustments).

your thermostat might be stuck open causing coolant to stay cold.
maybe check your timing too.

you might also check the output resistance of ECT for EFI sensor which ECM relies on.

ghettosled · 01-13-2011, 07:29 AM

can you clarify what you mean by "cleaning out the intake" - its rather vague. to me, the intake is the rubber/plastic duct working leading to the throttle body. have you cleaned out the idle air control valve that regulates the idle of the engine?

if the engine isnt warming up, that sounds like the thermostat is stuck open and not allowing the engine to warm up.

not shifting sounds like what lash70 suggested, especially if first, second and reverse function properly.

dhansen · 01-14-2011, 04:02 PM

Sorry for not explaining well. I sprayed out the throttle body with the air intake cleaner and sprayed a generous amount in the IAC per this video:

You Tube

The reason I disconnected the battery was I'd heard that the ECM needs to relearn the cleaner IAC. Sorry for my ignorance, I'm not much of a mechanic. How do I unstick a thermostat?

I'll check into Lash's recomendations...It's SO COLD OUTSIDE!!

Thanks again guys!