1998 pontiac grand prix gtp 4T65E HD tranny problem and dtc's!!!
daytonapacecarguy
04-06-2009, 08:53 PM
First off i bought the car from my father about 4 days ago.From what he has informed me of here is what i have got.To start with the car has 170,000 miles on it the tranny has never been serviced since he had it.The first problem he administered was about a few months ago he encountered a po102 dtc that says mass air flow low input.He then drove the car with the SES light on up until just recently a week ago he was heading home and the tranny started a loud whining noise and stopped pulling.He stopped the car,turned it off,waited a few mins. and started it back up and drove a few more miles until it happened again.He then went through the same routine before he made it home.Afterwards,he decided to change the tranny fluid and filter which had some slug build up in it but otherwise still reddish.No metal or other objects where noticed in the pan.He then drove it for approximately another 200 or so miles noticing as the car shifted into 4th or high gear he could feel a shudder or jerk while engaging into that gear.Then the tranny failed again.Since then the car has not been driven.After plugging a DTC scan tool into the car i have received 4 DTC codes.They are as follows:po102 mass aif flow sensor circuit low input,po141 O2 sensor heater malfunction downstream sensor,po742 Torque Converter Clutch [TCC] stuck on and a po756 2-3 shift solenoid performance or stuck off.I then pursued to deleted these codes from the PCM's memory and did now the car will not move it feels as if every gear is neutral!!Now i would like a little information on the possible causes of this please.From my understanding the MAF sensor has something to do with the 4T65E hd tranny operation.The tranny also has 2 main solenoids besides the shift solenoids they are the EPC solenoid and the TCC solenoid.From my understanding i have been informed that replacing the TCC solenoid might fix this problem.I have tried some Lubegard and the car want move the pump will whine on start up and then after a min. or two it will stop but the car want move.I can unplug the mass air flow sensor,which i am figuring is bad and the whine comes back the SES light will set and the car will attempt to move but not much.PLEASE HELP THANKS!!!!
tblake
04-06-2009, 09:39 PM
The P0102 will have nothing to do with the trans operation. Just leave the MAF unugged for the time being while you diagnose/repair the trans.
P0141 I would hold off on worring about at the moment as a failed O2 sensor heater circuit will not cause a car to not shift gears
P0742 scares me. Replacing the TCC solonoid is generally not a DIY job.
P0756 sounds like a failed 2-3 shift soloniod or wiring problem. This code in conjunction with P0742 almost makes me wonder about the trans internal wire harness or the plug and wireharness and fuses for the trans.
You could check all your fuses and wires leading to the trans, and also maybe unplug, clean out and reseat the trans electrical connectors.
P0141 I would hold off on worring about at the moment as a failed O2 sensor heater circuit will not cause a car to not shift gears
P0742 scares me. Replacing the TCC solonoid is generally not a DIY job.
P0756 sounds like a failed 2-3 shift soloniod or wiring problem. This code in conjunction with P0742 almost makes me wonder about the trans internal wire harness or the plug and wireharness and fuses for the trans.
You could check all your fuses and wires leading to the trans, and also maybe unplug, clean out and reseat the trans electrical connectors.
tblake
04-06-2009, 09:39 PM
welcome to AF by the way!
lisas98gtp
04-05-2010, 08:37 PM
i am having the same problem. what did you ever figure out?
gdaddy3
05-07-2010, 09:07 PM
Pacecarguy...........I also own a 98 Grand Prix Daytona Pace Car......Have you ever tried to find out the bluebook value of your car. I have one that I just wrecked a few weeks ago. I cant find a publication that lists Daytona PC as an option for the 98 GTP when figuring the blue book value. It obviously is going to add to the value of the car. I want to make sure that the insurance company is aware of this so I dont get screwed. If you've ever looked or know where i can find this out, let me know. I hope you got your tranny issue fixed......Gdaddy
BNaylor
05-09-2010, 12:56 AM
Pacecarguy...........I also own a 98 Grand Prix Daytona Pace Car......Have you ever tried to find out the bluebook value of your car. I have one that I just wrecked a few weeks ago. I cant find a publication that lists Daytona PC as an option for the 98 GTP when figuring the blue book value. It obviously is going to add to the value of the car. I want to make sure that the insurance company is aware of this so I dont get screwed. If you've ever looked or know where i can find this out, let me know. I hope you got your tranny issue fixed......Gdaddy
Please keep the discussion on topic to the issue(s) of this thread. If you want to address the member directly with the questions you presented then you can send them a private message (PM) or an email but no guarantee the member will respond as you can see in this old thread.
Please keep the discussion on topic to the issue(s) of this thread. If you want to address the member directly with the questions you presented then you can send them a private message (PM) or an email but no guarantee the member will respond as you can see in this old thread.
Automotive Network, Inc., Copyright ©2025