Need a Little Help with a Code
Thread Starter
Melting Slicks
Joined: Jul 2005
Posts: 2,649
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Need a Little Help with a Code
So - had my '12 GS Auto out for a ride a little while ago - drove it about 75 miles and parked it. When I got back an hour or so later, I started it up, and the Check Engine Light was on. OK - the car seemed to be running fine, so I drive it the 75 miles back home - stopping to get gas along the way. The car seemed to drive normally.
When I got home, I pulled the code, and it was PO601. (And needless to say - I could not clear it.)
So check the service manual and that code is "Transmission Control Module (TCM) Read Only Memory (ROM)" According to the manual - the condition for setting the code is that the ROM (in the TCM) test has failed 5 or more times.
OK - did a bit of searching, and it seems that with the 6L80, the TCM is in the transmission. It appears that the TCM is "part" of the Control Solenoid and Valve Assembly. Checking the normal on line parts sellers - I can not find a part number for the TCM. After a lot of searching - it looks like I probably want part number 24275873 - which can be had for about $420 (plus a core charge). It also looks like it needs to be programmed after installing.
So - a few questions:
1) The Service manual indicated that when any of the PO601 - PO604 codes occur - the trans controller selects a gear and turns off - but on my drive back home - the car was shifting - seemingly normally. Does this make sense ???
2) This seems to be a job that requires a lift, as you need to pull the pan and filter to get to the module / assembly, and obviously after the module is removed and changed - the trans fluid has to be refilled, and the level set through the GM procedure. But has anyone actually done this job ???
3) Does the reprogramming have to be done at a dealership - or are the shops that do dyno tuning (utilize HP Tuners etc.) . able to do this kind of work ???
I have no real experience with the dealership service departments near me, and really would prefer not to go to a dealership if at all possible.... I'll probably give ECS a call next week, and see if I get the prt, if they can install and program it...
When I got home, I pulled the code, and it was PO601. (And needless to say - I could not clear it.)
So check the service manual and that code is "Transmission Control Module (TCM) Read Only Memory (ROM)" According to the manual - the condition for setting the code is that the ROM (in the TCM) test has failed 5 or more times.
OK - did a bit of searching, and it seems that with the 6L80, the TCM is in the transmission. It appears that the TCM is "part" of the Control Solenoid and Valve Assembly. Checking the normal on line parts sellers - I can not find a part number for the TCM. After a lot of searching - it looks like I probably want part number 24275873 - which can be had for about $420 (plus a core charge). It also looks like it needs to be programmed after installing.
So - a few questions:
1) The Service manual indicated that when any of the PO601 - PO604 codes occur - the trans controller selects a gear and turns off - but on my drive back home - the car was shifting - seemingly normally. Does this make sense ???
2) This seems to be a job that requires a lift, as you need to pull the pan and filter to get to the module / assembly, and obviously after the module is removed and changed - the trans fluid has to be refilled, and the level set through the GM procedure. But has anyone actually done this job ???
3) Does the reprogramming have to be done at a dealership - or are the shops that do dyno tuning (utilize HP Tuners etc.) . able to do this kind of work ???
I have no real experience with the dealership service departments near me, and really would prefer not to go to a dealership if at all possible.... I'll probably give ECS a call next week, and see if I get the prt, if they can install and program it...
