1994 Isuzu Trooper



November, 20, 2008 AT 5:34 PM

Transmission problem
1994 Isuzu Trooper 6 cyl Four Wheel Drive Automatic 130000 miles

My transmission is not shifting automatically. The check trans light is flashing as well. It will shift If I shift it into low gear then up shift as I accelerate. If I don't do this it seams like it is trying to take off in 3rd gear and accelerates very slow.


Trans Not Shifting


Not Shifting


6 Answers



November, 21, 2008 AT 1:16 AM


Need some specifics on your vehicle to ensure we are looking at the correct model.

Is it a LS, RS, S, or SE. Next, is the engine a 3.2L SOHC or 3.2L DOHC?

Next please go to Auto Zone or O'Reilly's and for FREE they can pull the codes to the car. Most important: Once they check your codes, if they find something and you don't get it fixed and need to get back with us, please make sure you tell us exactly what the code was, number and all. Example, if the code was E0568 O2 Sensor bad. Then make sure you give us all of that. While there for FREE also they can bring their tester out and check your battery, alternator and starter.

Provide this info back and we will have a starting point.



November, 21, 2008 AT 11:40 AM

OK it is a 3.2L SOHC enginge. Not sure if it is the S or LS but the VIN is JACDH58V7R7918645. It does not have an OBD II port to check for codes. It only has a three terminal port hanging from under the dash.

When I ground the two outside terminals on the port together as it describes in the not so helpful Haynes manual, I do not get any fault codes. It just keeps flashing the # 12 system acknowledgment code. The check engine light has not lit up yet but I have a check trans warning light that keeps flashing. I'm sure this is trying to tell me what the problem is but I can't find any info on what this warning lite is for.

I did drive it on the highway today and found out that it is not shifting into O/D either.

Thanks for your quick response in trying to answer my question. Let me know if I can give you any more info that could help with trouble shooting.




November, 21, 2008 AT 10:01 PM

Hello -

Also, one of my tech manuals wants to know if it is a LS, RS, S, or SE. I know you were not sure, but is there an emblem on the back or side?

I was able to find some info on the VIN for you....I would keep this. It did answer my door question.......

I am going to use the RS model for now.

Of course, you need a TECH 1 scan tool.......can you break in.......sorry...just kidding.....but, this does show you can jump pins 1 and 3 and get the Check Trans Light to flash also and count the codes. I attached the info for you. Now I know you did that for the check engine light, but this says for the trans light also. As a matter of fact, the pic I am giving you shows the Diagnostic Connector as a 2 pin and the TCM/ECM as a 3 pin. That way you can hook the TECH 1 scanner up to the 2 pin and still jump the TCM. If you can not, then you need to at least have the shop do this for you, give you the codes and tell you what they are also. But get the code numbers.

This would be great if you can get the codes though.

Right now, based off what you said that it is not shifting, the TCM contains a fail-safe system. When failure or problem exists in transmission electronic control system, the TCM may go into a back-up mode using pre-programmed values, allowing vehicle to be driven. The CHECK TRANS light on instrument panel will flash to inform the driver of a problem. The vehicle can be driven BUT shifting must be done manually. So, back to the codes.............but at least you know why you have to manually shift.

Based on what you said about starting off in 3rd may be. The transmission has 3 different shift modes, Normal, Power, and Winter as I said. There is a TSB on the winter switch has failed. I have attached that for you.

Well, if you can not get the cold take a chance and replace the winter switch and see if that fixes everything. Or, have the codes checked to make sure what is wrong.

Last, it looks like you may have some recalls on your vehicle. The dealer may fix these for free. Please contact the dealer service department, give them the VIN number of your car and have them check on these to see if they apply to you.

Hope this helps.


DATE 1994


SUBJECT: Third gear starts


Third gear starts

This condition can be caused by a winter switch (if equipped) that has failed, closed. When the winter mode is selected by the driver, the computer commands third gear starts for better driveability on snow or ice (the unit will still shift to fourth gear at the appropriate speed).

If the switch fails (closed) it can continually send a winter mode signal to the computer. For a quick test of the switch, turn the key off, disconnect the winter mode switch harness connector and drive the vehicle. If the transmission returns to normal operation replace the switch. The Isuzu part number for the switch is: 8-94368-568-1.




November, 22, 2008 AT 6:26 AM

Thanks for the info. I will see if I can get a Tech II scanner. I will be out of town this weekend so I don't know how far I will get so you may not hear back from me until Monday or Tuesday.

Thanks again for the info, it looks to be very helpful.



November, 22, 2008 AT 9:26 AM

No problem. But remember, I don't think you need the scanner. Try shorting 1 and 3 pin together on the 3 pin connector and see if the trans light flashes. Then that way you can just count the flashes and you won't need the scanner.

Have fun this weekend



October, 24, 2009 AT 2:52 AM

Hi all,

(Sorry for my poor english)

i have same promlem but my car is opel omega-b.1997 model, x20xev and gearbox is 4L30E. All symptoms are same, not shifting automaticaly. Suddenly automatic gearbox check appeared on high way. Shifting manually, but not shifting by itself. No kickdown-no sport-no winter mode. Disconnected winter and sport mode but no result. When automatic gearbox check appeared, I checked by tech 2 scanner and fault was 130-130-1110-0430, o2 sens√ r and camshaft. Checked the transmission by tech 2 and fault was -pressure regulator solenoid circiut open. Later checked many times no camshaft error. Runing without problem at first start. RPM is okey, up to 4500-5000. Rpm.

I have done these; 1-ATF changed
2-solenoids changed (all solenoids)
3-disconnected winter mode button-sport button
4-head gasket
5-spark plugs
6-selector switch

i bought 5 liter gas and ready to fire it : )

i solved

tcm was the problem

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