4l60e no manual first gear and starts in 4th
03-27-2015, 07:01 PM
#1
4l60e no manual first gear and starts in 4th Freshly Rebuild 4l60e with and transgo shift kit. Vss, Oss, Rpm all read fine. Trans shows to be commanding 4th gear as soon as you start to roll. Try to manually downshift to first and it only goes to second. Will manually shift to 3 and 4th fine. Im using a Matco Scanner to watch pids, if i have solenoid problems will it show the pcm as "commanding" the 4th gear? Any help on this would be much appreciated.
03-27-2015, 07:48 PM
#2
Moderator
I have never heard of this, but the trans only does what the PCM tell it to.
Your choices are:
1. You are reading the commands incorrectly. (Just a reminder, not implying that.)
2. The PCM is defective
3. The PCM has the strangest tune
If the PCM were reading the VSS incorrectly due to electrical noise or wrong tune, I could see it commanding 4th gear immediately.
Your choices are:
1. You are reading the commands incorrectly. (Just a reminder, not implying that.)
2. The PCM is defective
3. The PCM has the strangest tune
If the PCM were reading the VSS incorrectly due to electrical noise or wrong tune, I could see it commanding 4th gear immediately.
03-27-2015, 08:04 PM
#3
It says "gear commanded" and when at a stop it read 1. As soon as you take off in OD it reads 4. And it feels like fourth. Vss and Oss go up and down seemingly normal "havent GPSed it". Is there a possibilty a 98 pcm doesnt work with a 01 trans? Can a bad map sensor cause an issue? Any thoughts on no manual first? Thx for the reply.
03-27-2015, 10:23 PM
#4
Moderator
Very strange indeed.
A '98 PCM works perfectly with any '96 through '07 4L60E; I have done it.
I think only the VSS and TPS control the shifting; and of course the tune.
I think the MAP/MAF will control the line pressure, but not the shift points.
A '98 PCM works perfectly with any '96 through '07 4L60E; I have done it.
I think only the VSS and TPS control the shifting; and of course the tune.
I think the MAP/MAF will control the line pressure, but not the shift points.
Last edited by mrvedit; 03-28-2015 at 08:25 AM. Reason: Tech detail
06-05-2021, 01:36 PM
#6
Same issue - old thread I know this is an old thread, but I’m having the same issue. No tune. On another thread, same symptoms, the OP determined it was a bad 3/4 solenoid and fixed it. Any more data or experience? Can anyone advise?
06-05-2021, 07:54 PM
#7
This is a better way to explain my symptoms. Another thread on another forum. This OP posted this years ago but did not post an update on what the issue was….
Same exact symptoms:
”so just today i was driving normally for about 5 miles and as i was at a light waiting for green i accelerated at green and it felt like the car lost all its horsepower and someone threw an anchor out the back like i was driving in 3rd gear so i manually shifted into 1st gear and i had gotten all power back and i put it in drive and was fine and stop at the next light same thing lost all power and back in 3rd so i manually shifted to 1st again back to normal it keeps doing this now fluid level is fine and fresh no service engine light is on or anything could there be trans codes still though?
is this a classic symptom of a shift solenoid failure??”
Same exact symptoms:
”so just today i was driving normally for about 5 miles and as i was at a light waiting for green i accelerated at green and it felt like the car lost all its horsepower and someone threw an anchor out the back like i was driving in 3rd gear so i manually shifted into 1st gear and i had gotten all power back and i put it in drive and was fine and stop at the next light same thing lost all power and back in 3rd so i manually shifted to 1st again back to normal it keeps doing this now fluid level is fine and fresh no service engine light is on or anything could there be trans codes still though?
is this a classic symptom of a shift solenoid failure??”
