1995 Jeep Grand Cherokee 4X4 4.0L 42re transmission
In order to get the tranny to work right I have to turn the key on five to ten minutes before I plan on driving. If I don't, then the tranny starts in 4th gear. I can pull it into 2nd or 1st position and it will be in 2nd until the revs get up then I can go to 4th. There is no overdrive when this happens. There is no doubt about what gears it's in when this happens, I've confirmed it by checking tach speed vs. speedo when things are running right.
If I do the delay start thing and it is working right, usually when I turn it off for short stops into the Post Office or the hardware store, it will work right without having to go through the delay procedure. But if is does go into the 4th gear mode, I can usually pull it out quickly be cycling the key four times - letting the code flash 55 and then it's back to normal. If not, then turn the key on for al least two to three minutes, and then itís OK.
I've been to two Jeep dealers, one independent shop and one transmission shop and being it hasn't thrown a code, the only thing they all came up with was the governor solenoid and the transducer are a real problem with this transmission. I replaced both of them and it's not changed anything.
Iíve heard that there was one series of transmissions that had a problem with the ground connections with the solenoid and the transducer. And the next series had an upgrade to fix that. But WHERE could that be? In the tranny, at some connector or where?
Now Iím convinced that there is no problem with the transmission, itís only doing what itís told to do.
What do you think? Or better yet does any one know what is wrong?
I want to say its a speed sensore but I really dont know
94 ZJ I6 Second 4.0 as of 226k Aftermarket Intake, Flowmaster 40 series, Rear Discs
05 Kawasaki Ninja ZX-6R 636 just ridiculously fast
96 Nissan Altima 5 speed stock and probably keepin it that way aka the beater or commuter car who wouldnt buy it for a grand with how gas is
So what's your reasoning? That the speed densor is telling the ecm or tcm that it is up to speed and should be in 4th gear? But if that was the case then why would it not be able to go into overdrive when the time was right?
I had a problem with my 94 ZJ, same 42RE. I ended up finding out that it was the transmission computer. $50 from junk yard 3 years ago still no problem. If the electrical goes on the trans computer, you only have 2 & 3 gears. It sounds like it might be the sensor telling the TCM or the TCM. Good luck.
Inside of the vehicle adjacent to the steering column. The mounting hardware for it is in the engine compartment for it. Remembering about it: I had a couple of troubles with it changing gears for me, lasted months couple of months before it went. Some acted like I had bad gas when I drive down the highway. I also checked for codes after mine went and it did not give any. One last thing: when you check the codes for the tranny, are you getting them from the engine light or the tranny OD light? The tranny diagonstics flash on the OD light.
Try the procedure for the tranny codes: turn key on and off 3 times and leave OD switch in normal on position. Then count codes. 55 is end code transmission. I have the shop manual if any other numbers come up for ya. When I changed mine, all I got was 55, but it still didn't work. Good luck.
I tried to get my TCM to store a code but it did not. Even though the FSM states that it does, I still have only heard one person retrieving them. I yanked CTS plug and drove around the block a few times. The PCM got the code but not the TCM?
The TCM, transmission control module, will throw codes just like the Power Control Module will. I believe there are only separate TCMs on the years 1993 to 1995. To read the codes you count the number of times the Over Drive lamp lights. The Over Drive lamp is located on the over drive switch.
Extracting Fault Codes:
Without ever starting the engine Turn the ignition switch ON, OFF, ON, OFF, ON and observe the Over Drive lamp. The Over Drive lamp should begin to flash a series of codes. The flashes will be separated by short and long pauses. The long pauses separate the "ones" and "tens" positions, and each code from the next. A code 55 will be displayed at the end of the test.
Tranny codes for 1994 OD button LED
11 Engine RPM input
12 Output shaft sensor input
13 Vehicle speed input
14 Governor pressure sensor input
15 Throttle position sensor input
16 Transmission fluid temperature input
17 Overdrive override (control) switch input
18 System voltage
19 Internal fault in module
21 Governor pressure solenoid output
22 Overdrive solenoid output
23 Converter clutch solenoid output
24 Overdrive override (control switch) lamp output
25 Internal fault in module
26 Governor pressure sensor offset drift
55 End of code transmission
94 Black Laredo 4-Liter with QuadraTrac (42RE trans & NP249 TC) 200,000 + miles purchased new
88 Cherokee 2-door with 5speed manual 139K miles(deceased) purchased new