42 RE transmission solenoid

[TurboPirate]

Hello gang, a bit of help here, got problems with this transmission on my Jeep Grand Cherokee Laredo 1995, it giving me transmission code 26, something about Governor solenoid, but I also know the TCM of this Grand Cherokee like to burn a relay inside the TCM and a capacitor, anyway I just want your input on this matter..I.......... The Jeep runs perfectly for about 20 minutes then it goes to one speed doesn't want to shift, I wait for 5 minutes and it runs perfectly again, my other Jeep has a different transmission, 2001 Jeep Cherokee Sport with AW4 transmission.....Thanks in advance TP

[auggie]

Have a Read here: hxxps://www.jeepforum.com/threads/1995-42re-code-help.281062/

Sounds like the same Problem your having etc. (Junk yard TCM seemed to fix it)

[TurboPirate]

True, I prefer to fix the TCM, it's a relay and a capacitor that needs to be change, thanks

[TurboPirate]

Change the sensors, new oil filter, new ATF+4 fluid and no more code 26, I also adjusted the atv cable, the only thing I noticed is first gear, it feels like I have stall converter, first gear fully applied if a Rev the engine a bit and it wasn't doing that before...........time to check everything else in the transmission...........TP

[TurboPirate]

I found it is not a stall problem, what is happening is that it is not engaging 1st gear, not even if I manually shift into first gear, I might have to remove the transmission to check for something broken, first 3 speeds of this transmission are hydraulic the electronics of this transmission is for 4th gear and torque converter clutch and those work......any ideas what to check before removing the transmission?

[auggie]

Not sure this will help but maybe worth a Look: hxxps://www.cherokeeforum.com/f5/transmission-troubles-42re-263206/

Also what I read is The governor pressure sensor, and solenoid pack are cooked ?

[TurboPirate]

Not sure this will help but maybe worth a Look: hxxps://www.cherokeeforum.com/f5/transmission-troubles-42re-263206/

Also what I read is The governor pressure sensor, and solenoid pack are cooked ?

The governor sensors are new.....

[The Noof]

If both 1st gear modes (manual & auto) yield the same result (no 1st), it isn't electronic...it's mechanical.Manual 1st eliminates the electronics by the valve body directing pressure directly to the appropriate clutch.The PROPER test is to locate 1st gear test port on the trans case & do 2 things:Put the vehicle in the air so the wheels can rotate freely.Start & run it in 1st gear,manual mode.Check the pressure via the test port & compare it to specs.If it's low,shut the vehicle off & air check the clutch pack via the same port.The test results will tell you if it's valve body (hydraulic) or clutch pack.I used this method to PROPERLY diagnose many auto trans/transaxle issue throughout my 44 year career as a self employed auto tech.
Don't keep throwing parts & time at it until it's fixed.

[TurboPirate]

If both 1st gear modes (manual & auto) yield the same result (no 1st), it isn't electronic...it's mechanical.Manual 1st eliminates the electronics by the valve body directing pressure directly to the appropriate clutch.The PROPER test is to locate 1st gear test port on the trans case & do 2 things:Put the vehicle in the air so the wheels can rotate freely.Start & run it in 1st gear,manual mode.Check the pressure via the test port & compare it to specs.If it's low,shut the vehicle off & air check the clutch pack via the same port.The test results will tell you if it's valve body (hydraulic) or clutch pack.I used this method to PROPERLY diagnose many auto trans/transaxle issue throughout my 44 year career as a self employed auto tech.
Don't keep throwing parts & time at it until it's fixed.

Thanks, I installed the solenoids because it gave me code26, after thar it ran perfectly until I had to slammed the brakes a kid ran after his ball when I took off that is when I notice it wasn't running like it was, what happened when I slammed the brakes? No clue, but it did run perfectly after solenoids change and no more code26........I'll check the pressure port.......I did tried manually into 1st gear but it doesn't.......I will also check the solenoids installed if I left something loose....thanks again............TP

[TurboPirate]

The Noof, on the governor solenoid there is a torn bolt, is it for adjustment? On my S10 Chevy 4L60 the EPC has the same bolt, I adjusted a quarter of a turn and I got more solid shifts, on this 42RE what is it for? Thanks, I search but didn't find any information on that.............TP

[The Noof]

The images I've been looking at don't show any fasteners/adjustments at all.Post a link to what you see so I can see what you're looking at.At the end of the day, if you have to "tweak" pressures enough from factory specs to get 1st gear, you will only be covering up the real issue.I don't see how the govenor solenoid will cause the loss of pressure to first gear:it's used for shift point calculation.

[TurboPirate]

20221215_131559.jpg

That one, the new solenoid has it too,
I ask for curiosity not to fix the problem, I know this tranny is not the same at all like the 4L60 but I want to know what is it for

[The Noof]

20221215_131559.jpg

That one, the new solenoid has it too,
I ask for curiosity not to fix the problem, I know this tranny is not the same at all like the 4L60 but I want to know what is it for

Looks like it may be a calibration adjustment:it probably butts up against a spring inside.Turning it will probably alter pressure of the circuit.

[TurboPirate]

Looks like it may be a calibration adjustment:it probably butts up against a spring inside.Turning it will probably alter pressure of the circuit.

Probably to adjust pressure to a just rebuild transmission, I don't need to because it worked perfectly until I slammed the brakes, thanks for clearing that out............TP

[TurboPirate]

OK, I removed the pan, checked what I did and all is good, assembled everything back and disconnected the battery for a few minutes, I test drive the same thing, but after a full stop I shifted the tranny to Neutral rev the engine up to 1,500rpm for 10 seconds released the gas pedal shifted to Drive and it shifted to 1st gear. What will cause this delay that if I Rev the engine for 10 seconds it will then shift into 1st gear everytime I fully stop? No clue, accumulator? Spring that holds valve in valve body?