I bought an 02 L200 (3.0 Automatic) as a winter car, but decided to keep driving it this summer, its been okay. So far I have replaced the RF lower control arm, front struts, tie rod ends, ball joints, and a sway bar end link, as well as pads all around, new rear brake lines and new front rotors.

It could still use rear struts and a bushing in the front of the LR trailing arm but drives decent.

Last week while on a trip I stopped for gas, when I went to turn it back on the key would turn all the way to start but nothing would happen, no solenoid click or anything. After about a half hour it started fine and got me home.
A few days later I was driving home and the wipers started acting up, on low I can hear a relay in the dash or column clicking and the wipers will stop at the end of their upward travel and the end of the lower most travel.
Okay thats manageable.
Then yesterday I run into town quick, when I left the store it started fine but I noticed the RPMs seemed high, looked down at my gauges, no speedo, tach was working intermittently (3000, 0, 3500, 0 etc) and the gear selector displayed that it was in 3rd no matter what detent it was actually in, and would not shift into over drive, so there i was going 40 through town trying to stay off the rev limiter.
Today I go to pull it into the garage and it took a few tries to get it out of park like the brake switch wasnt working ( I do have brake lights)

I had a similar issue on a cobalt that ended up being the wiring to the speed sensor on the transmission, the speed sensors on the front knuckles look fine all the way up through the inner fender so I think I can rule that out.

So do I have some separate issues going on? Or is there a common problem I missed when I was doing some googling earlier?

Thanks

 

Sounds like a body control module problem. It controls just about everything on these cars. The sensors at the wheels are for the antilock brakes and traction control. There is an output speed sensor in the transmission that tells the bcm what to do with the speedo. Bcm failures are pretty common with these cars.

 

I should've known about the output being on the trans, I checked those and the wires are fine.

Doing some more research it seems that the transmission range sensor / neutral safety switch can have some issues on these.
If thats the case it would explain why it didnt start that day, as it acted like it would if you tried to start with the car in drive.

I tried my scan tool to see if there was a range code, of course its not working. Rented the autozone unit and it wouldnt connect to the vehicle. So I guess Im loading up the parts cannon and throwing money at it ...

I put an order in for the range sensor and it should be here tomorrow. |

Also assuming the wipers are separate issue for now.

 

I do have a complete set of factory service manuals for a 2002 L series. If you can get any codes out of it I can look them up. Generic OBD2 codes are only emission related so you need a better scanner to get real data.

 

Took it to a friends shop today and he was able to get a U2106 code out of it.

I took the TCM out and started it for the heck of it, all gauges but the speedo work just fine. There still is no 4th gear.

Went and grabbed a junkyard TCM, same issue as the original TCM.

Im thinking wiring somewhere but not sure where to start. Could you hook me up with some diagrams from the TCM to the BCM, and the PNP switch to TCM, and maybe a ground location diagram ? Im thinking the issue is somewhere in there, just gotta find it.

 

Yes I can help with diagrams and troublshooting your automatic. Maybe tomorrow night.
Andy

 

Ok first I need a clarification, you list a L200 which in 2002 is a 4 cylinder car, yet you also list a 3.0L which would be a L300. You also mention a tcm which is under the wiper cover inside the cabin. So I will assume that you really have a L300.

 

U2106 is a Ecm code not a tcm code. The ecm Has lost communication with the tcm. I have to get the body control manual for that code.

 

 

Yes, you are correct l300. I'm not sure how I typed l200 twice.

Thanks for the diagrams I'll see what I can come up with.