Thread: P0753, P0758, P1860, 1-2 and 2-3 shift solenoid and TCC pulse width modulator errors

Hello this is my first post on here. So Im thanking all of you for any input on this problem. Here it goes............

Im having transmission problems on my 2001 GP-se. First off its giving me these three error codes (P0753, P0758, P1860), 1-2 and 2-3 shift solenoid and TCC pulse width modulator errors. When you stick it in Drive and take off it starts out in 3rd gear instead of kicking down to 1st. When you pull it down into 1st it will only take off in 2nd gear, or while driving I can pull it form 2nd to 1st and it will not engage 1st gear ever. It will not kickdown while moving in drive if I step on the pedal to get it up a hill, I have to pull it down into 2nd to get it moving. I have checked voltage down to the trans housing on the harness connector. Im getting the proper 12 volts to pin E on the harness, and also checked the resistance of each solenoid on the transaxle case connector. 1-2 gets 23K, 2-3 gets 23K, and TCC is getting 12K, I have also Cleared these error codes after testing and they keep coming back. My routine to get the car moving consists putting shifter in 2nd then shift to third then I can here it shift to 4th but the convertor never feels like it locks up, I have to do this since if I leave it in drive it stays in 3rd. I looked at the ohms resistance chart and see that all three of my error codes are tied into pin E (pink) on the harness. 1-2 is A-E, 2-3 is B-E, TCC is T-E, I have checked there resistance by going through A-E for the 1-2. Im not sure if my 1-2 solenoid is stuck in 2nd or if I have a problem with my range selector. Im lost as of now and will be greatly appreciated of any knowledge I can pull from you guys/gals.

Thanks,
Josh

I have verified 12 volts to pin E on the transaxle connector, also checked ground straps on the bellhousing. Im an f-body guy most of my LT1 Transam sensor's are in the thousands on resistance, this is why I said 23K instead of 23ohms so I know all the solenoids are testing correct. Im going to disconncect the harness from the PCM and check voltage up to the computer so I know Im getting a complete circuit. As soon as I type this up I will go test and reply back what I find.

Thanks a million for the quick response Trannyman95, I actual stumbled across your website before I found this message board and it has been very helpfull to me.

Josh

I also took it on a test drive and when I pull the 10amp fuse to the pink 12volt source it experiences the exact same symptom as when I get good power up to the PCM.

Do these cars have common problems with the PCM's going out? Also is there a range selector switch that would cause issues like this (where the cable runs to the top of the tranny)?

Those were the only codes it has been showing, I cleared and scanned them 3 times to make sure. Also I can manually shift through all gears just not into 1st, it only stays in second gear when shifter is in 1st. Is there a way I can ground the 1-2 solenoid to get it to shift into first then second just to verify my 1-2 solenoid is good? When in drive it stays in 3rd the entire time until I shift it manually, does this still sound like pcm or maybe tps going out of calibration?

I can get a PCM directly out of the same model car as mine 2001 3.1 se, Will this PCM need reflashed to match my vin or could I just drop it in and run it? I will not care if there is a Check engine light because of not being vin matched as long as it shifts and runs my engine.
Trannyman95 you have been great help, thanks.
Josh

I got to bring this old thread back up and ask if anyone knows if the PCM did the trick? I have the exact same problems on a 00 Grand Prix and I'm debating on wether or not to try the PCM.I'm assuming the PCM fixed the problem since StockTA never responded for more help.
Just thought it was worth a shot to ask.
Thanks,
James

Im sorry about not updating the status of the PCM fixing my trans problem, I honestly was thinking about that a week or so ago. I actualy went to the salvage yard (LKQ) and picked up two PCM's just incase the one I brought home was dead out of the box. I had this pulled out of the same exact car (year, motor and trans and SE options) I was working on and the PCM bar code#'s matched up so in theory it should have plugged in and fired right up as I was told. Well that did not work, both PCM's I brought home would not start the car so YOU DEFINITLY HAVE TO RE-FLASH the code from your old PCM to your new replacement ($75-$90 for dealer to reflash).

I actually ended up taking apart my PCM and checking the internal circuit board and saw that it was definitly commanding the shift selonoids. That had me digging into the wireing harness once again scratching my head at this problem. I put the car up on a lift and LOL I felt pretty blonde after I saw a entire other section of burned harness, duh.

The entire time it was the harness section that runs under the ac acumlator where I could not see it from above the motor. This must of been a ground that I missed because I retraced the wiring from pcm all the way into the pass-through connector going into the actual valve body to the shift noids. The pass through connector connections checked out good so if you guys have this problem check that other side of the harness so you dont end up chasing your tail. The only thing is my lock up torqe convertor is not kicking in at overdrive so I need to dig into her and figure out what I missed but It will probably get sold for my best friends GTP. I ended up taking those PCM's back and the 186,000 mile GP S.E. is still getting us to work as of now.

I want to thank trannyman

You saved me on what I thought was a mechanical problem and pointed me in the right direction to solve this. Cost me my time and your knowledge of these so thank you again and everyone on here have a great new year!!!!!!!!!

Josh

OK - Now I've fallen victim to this too... Same Check Engine codes and symptoms.

I was going to start with the fuse, but what fuse and where?

I just turned the heat on in the garage, and will be checking the harness next.

**SOLVED**

Years back when I bought my intercooler from ZZPerformance - they recommended using a 'pink' wire under the fuse box as the power source.

A few months ago; I replaced the crappy bilge pump with a BOSCH unit.

Well.... the Harness ZZP includes was NOT weather sealed. (no rubber grommet) This caused road salt / spray to corrode the connection, and effectively short out / burn off the pump terminals, and blow the TCC fuse.

I disconnected what was left of the pump harness, and replaced the fuse. All is well. Well - except for the IC pump