Hi Everyone,

I’m new to the forum, but have done numerous searches and have found a lot of helpful information, but am at a loss. I’m wondering if anyone can help me out. I have a 2001 LW300 (59k miles) that intermittently stalls. It’s been happening for a couple of years now, but started getting worse about 6 months ago.

The car will be fine for a couple of days and then out of nowhere, the revs will bounce and then the car will stall. Sometimes it will just stall out of nowhere at a red light or going 60mph on the freeway. Sometimes, it just won’t start at all. I just let the car sit for 3 weeks, took it for a drive today and although it didn’t stall, the revs would start bouncing.

I’ve replaced the ECM, throttle body, TPSensors and wiring harness, MAF, intake boot, crankshaft & camshaft sensors, coolant level and temperature sensors, various relays and fuses, air filter, and spark plugs. I had all of the wiring tested and everything tests out fine.

I’ve run the codes sever times over the past couple of months and got the following:

P0121 - throttle pedal position sensor / switch “A” circuit
P0221 - throttle position sensor / switch “B” circuit
P0606 - control module processor
P1516 - command vs actual throttle position correlation (TAC module)
P1523 - throttle actuator control
P1779 - engine torque delivered to TCM signal
P1780 - MIL requested by TCM
P1791 - TCM loop error

I don’t get all of the codes every time. It’s usually just P0221 and maybe one or two other codes. A few times, I’ve have up to 5 different codes.

My mechanic has taken the car for multiple days on numerous occasions and cannot figure out what is going on. I’d appreciate any suggestions anyone may have. Thank you in advance!

 

Andy is our resident L car guru.

Just some preliminary questions:

It's important to know which exact combinations of codes occur after a stall, which ones resolve themselves after a few successful trips in the car, and which ones never go away.

You've replaced alot of parts already, some of which could conceivably have removed some of the listed codes.

Please list which combinations of codes show up, which ones go away, and which ones never go away. It should greatly aid in troubleshooting.

It would be nice to know what tranny codes are being set in the transmission control.module (TCM). Any chance you could get those from your mechanic?

 

Hi derf,

Thanks for the reply. Here's a short history of some of the codes during stall situations. After I ran the codes, I cleared them, went for a drive (the car would stall) and then I'd run codes again. All of these instances were after the last part installation.

Listed most recent first.
3/18
P1779, P1791

3/17
P0121, P1791, P0221, P1779

3/17
P0221

3/17
P1516, P0506

3/13
P0221, P0121

3/13
P0221

As for the parts replacements, I did one part at a time starting with cleaning the throttle body. It ran great for a few weeks and then started with the stalling again. Then replaced the TB & wiring harness. Again, good for a week and then went back to old behaviors. Next up was the MAF and boot... same thing. Then the ECM... Then the sensors, etc. I tried to narrow it down along the way, but same thing happened every time.

To summarize, the following codes have all occurred both pre and post parts installation:
P0121
P0221
P0506
P1516
P1779
P1791

These following codes have not come back after replacing the parts:
P1780
P1791
P1523
P0606

I'm using a BlueDriver scantool app, and it does read transmission codes, but not once has one come up.

Please let me know if you need any additional information.
Thanks for your help!

 

I am sure there is a security issue with the new ecm/bcm. There is a relearn process but I have no information on a Vue. Maybe Derf has that.

 

Just now seeing your reply 02_LW300.
Sorry for not replying earlier.

We've been continuously trying to diagnose and fix the old Saturn. I idd run the relearn on the ecm when I first installed it. Also, its been throwing the same codes both before and after replacing it. Multiple mechanics have tried and failed at figuring out what the hell is wrong with this thing. I've received many great pieces of advice on another forum and have tried them all. I mean everything. Nothing has worked.

Most recently, we went through all of the wiring (again), but this time found a small section where a rodent had chewed through some of the wiring insulation. We repaired it, started her up and it boom - it was running beautifully. After ~300 miles, it started throwing codes, going in to limp mode and stalling. Just like it has always done.

After spending too many years and WAY too much money, I'm finally throwing in the towel. The Saturn won!

If anyone knows someone that is looking for a project or parts car, please hit me up. I'm in Oakland CA. If no one reaches out, I'm afraid I'm going to be donating the old lemon.

Sincerely,
Rich aka FedUpSaturnGuy

 

Ehhhh, Andy, he has an LW300, not a Vue. Would that make your reply any different?

 

Glad you stopped back in.

I know you said you replace the throttle position sensor. I believe there is something down by the gas pedal as well as something up on or mounted to the throttle body. Have you checked both of these for corrosion at the connectors?

Also we're both replaced as part of your parts extravaganza?

What codes do you get now when you drive it and it goes into limp mode or stalls?

Also, try reading codes when it is driving normally. You may find there are pending codes that do not yet light the SES light but they give insight as to the fact that a problem they already be detected as pending which should give you a head start on tracking down the road cause.

Has anyone actually checked the voltage versus position behavior by the throttle position sensor components?

It seems all TCM related codes had vanished which leads to it being either the throttle position sensor or something disturbing the throttle position sensor readings, like an intermittent loose power signal or intermittent corroded ground etc.

What wire was it that was chewed through by the small animal touring your engine?