WJ 2.7CRD p1130,p0703, p0702

[Svensson]

Suddenly had a problem today. Arrived back home and I couldn't put the Jeep in park. I was able to shift between R,N and D, but the light was stuck on D. Was able to drive both forward and backward. When I turned it off in N, I was able to put it park.

When starting it up again I had the yellow light on the engine, but able to shift between all gears. p1130,p0703, p0702 are the fault codes. I know what the codes are for, but what is the most likely reason for this?

Thanks in advance

[JeanLuke]

Originally Posted by Svensson

Suddenly had a problem today. Arrived back home and I couldn't put the Jeep in park. I was able to shift between R,N and D, but the light was stuck on D. Was able to drive both forward and backward. When I turned it off in N, I was able to put it park.

When starting it up again I had the yellow light on the engine, but able to shift between all gears. p1130,p0703, p0702 are the fault codes. I know what the codes are for, but what is the most likely reason for this?

Thanks in advance

The P0703 and not going into park I would expect to go together as a brake pedal switch failure. The P0702 could just be a sympathy error code. It often appears in concert with other problems.

I struggle to see how the P1130 could be related. It belongs to the fuel rail pressure regulating system. That is a separate system to the transmission.

A wild guess - check your battery condition. Measure the voltage while cranking. Much below 10V and you have issues (technically it is 9.6V after 15 seconds of cranking). The ECU dies at around 9V, so a low voltage could be causing it to throw spurious errors.

Check also the earth connection to both the engine and chassis. Make sure the bolts are tight. Then measure the voltage while cranking between:
1/ The negative battery terminal and the engine
2/ The engine and chassis
3/ The chassis and the negative terminal
They all should be only a fraction of a volt.

I might be sending you on a wild goose chase, but these are simple tests that can quickly eliminate an underlying battery problem.

Sent from my Lenovo YB1-X90F using Tapatalk

[Svensson]

Originally Posted by JeanLuke

The P0703 and not going into park I would expect to go together as a brake pedal switch failure. The P0702 could just be a sympathy error code. It often appears in concert with other problems.

I struggle to see how the P1130 could be related. It belongs to the fuel rail pressure regulating system. That is a separate system to the transmission.

A wild guess - check your battery condition. Measure the voltage while cranking. Much below 10V and you have issues (technically it is 9.6V after 15 seconds of cranking). The ECU dies at around 9V, so a low voltage could be causing it to throw spurious errors.

Check also the earth connection to both the engine and chassis. Make sure the bolts are tight. Then measure the voltage while cranking between:
1/ The negative battery terminal and the engine
2/ The engine and chassis
3/ The chassis and the negative terminal
They all should be only a fraction of a volt.

I might be sending you on a wild goose chase, but these are simple tests that can quickly eliminate an underlying battery problem.

Sent from my Lenovo YB1-X90F using Tapatalk

Thanks for the respons! Not sure why the p1130 code still is there since have replaced this part 2 years ago or something.

Im gonna go with a quick brake pedal switch replacement. Seems intermittent since the car runs and shifts like normal today, but mil light is still on. Does this mean its a ongoing fault? I should check all the earth connections anyway since I have a slight problem with the jeeps battery when its cold. Battery is relatively new.

[JeanLuke]

Originally Posted by Svensson

Thanks for the respons! Not sure why the p1130 code still is there since have replaced this part 2 years ago or something.

Im gonna go with a quick brake pedal switch replacement. Seems intermittent since the car runs and shifts like normal today, but mil light is still on. Does this mean its a ongoing fault? I should check all the earth connections anyway since I have a slight problem with the jeeps battery when its cold. Battery is relatively new.

Try clearing the error codes and see if the P1130 comes back. You'll find the software to do it at jeepswj.com. If it comes back, then you have an ongoing fault.

Checking the earths should be fairly quick and simple, except it will take two - one to watch the multimeter under the hood and one to crank/start. It will eliminate a potential (but seemingly unlikely) cause.

Sent from my Lenovo YB1-X90F using Tapatalk

[55zed]

Sometimes the MIL light will clear itself after a few driving cycles, as long as it's not in limp home mode..

[bodgie]

There are several lockout solenoids on the shifter mechanism. I suspect one of them is failing and creating the problem.

I had a similar problem on mine years ago. I found one solenoid on the passenger side from of the shift mechanism that was very hot and seemed to stick in the wrong position. A quick snip with some wire cutters and a cable tie from memory and the problem was resolved. It hasn't impacted the safety or operation of the transmission BTW.

Jason