Various DTC Codes, Transmission Not Shifting Into 4th Gear

[p1nkp0sse]

2004 Chevrolet Aveo A/T 65k miles

Just replaced all 8 exhaust valves because of a broken timing belt. I also replaced the fuel pump with a used unit from a 2005 Aveo. Now that I have put the car back together and now getting the following DTC codes:
p0118 (Engine Coolant Temperature Circuit High Input)
p1781 (Transmission control module TCM mil request circuit)
p0700 (Transmission control system-MIL request)
p0452 (Evaporative Emission Control System Pressure Sensor Low Input)
p0122 (Throttle Position Sensor Low Voltage)

When I start the engine, it immediately revs up to 3500 rpm and drops down to just above idle speed, over the course of 15 seconds. Transmission doesn't shift into 4th gear. Hard shifts when in D, but if I use HOLD and start in 1 and shift up to 2, then D as acceleration build, the shifting is softened. Any help you guys can provide would be hugely helpful!

[thehunterooo]

you went past the 60k mark without the change lol

not too bad if the 8 valves only got messed up, there is another thread on here related directly to these codes, some are the same, ill have to go look for it real quick

i thought on the other thread that there is something wrong with the throttle body, but rabbit and others also have some really go info on this

[nole07]

my 2004 aveo just hit 75k miles and its throwing the same codes, it wont shift into OD(4th) gear on me either. mine also jerks when i put the car in drive or reverse, probably an engine mount there, but none the less. i'm taking it to a dealership tomorrow to see whats wrong, hopefully its just a sensor or solenoid or something. i'll keep ya posted.

[thehunterooo]

must be a sensor somewhere, im almost at 50k and im still doing good

the tranny fluid was drained and driven about 3 miles before fluid was put back in, it shifted hard the next 20 miles, and now it is better than before, some hardcore stuff lol

ill find that thread

[thehunterooo]

viewtopic.php?f=51&t=27776

i didnt know it was your thread nole

[nole07]

yeah my thread lol, i replaced the TPS...no luck. I was told by a friend that is a mechanic that it is most likely the Pressure Control Solenoid in the transmission. was suppose to go to the dealer today, they were booked up, going wednesday.

[thehunterooo]

they is it most likely, my friends escort had this similar problem, sometimes it wouldnt shift, something is not being sent right from the engine

i always thought it was the TB, either being defective or dirty, but in most cases its what you are fixing when you get the chance lol

[petrified.rabbit]

p1781 (Transmission control module TCM mil request circuit)
p0700 (Transmission control system-MIL request)

these are the two codes the dealer will be able to read the actual meaning of.. you just have the generic meaning.
Knowing what the code is by reading the TCM with an actual "gm" scanner will give a more precise code.

[p1nkp0sse]

Thanks for all the replies. I have read all of the suggestions you guys have had and been to the posts listed here too, but I'm still stuck as to what I should check/replace next. Everything worked on this car before the timing belt failure.

One symptom I forgot to include is that when I put the car in D shortly after starting it, it surges forward at a higher rate than normal (about 20mph versus 10mph without touching the accelerator). This leads me to think that the root of my problem is likely with the TPS. It seems logical to me that is the transmission is unable to read where the throttle is, then it won't know when to shift. Only flaw with that theory is that it shifts normally up through 3rd gear. Can anyone backup my logic? Also, would anyone suggest flashing the ECU with a CKP System Variation Learn Procedure to fix my issues?

I am desperately trying to avoid the dealer at all costs. Looking forward to what you find out Nole! Thanks again for all your help!

[thehunterooo]

i would suggest the dealer if all else fails, i hate to say it but that may really be the only way to get it fixed, if you know of a good dealer then it shouldnt be too bad