I have an "Engine Fault" warning script reading on the dash panel; but no amber check engine light.

My OBD code reader comes up "System Pass" showing no codes. Pending codes reads P1000 which I do not understand the meaning.

I runs fine for about 50 miles now, EXCEPT once it went into "Gearbox Fault" on the dash script; went into limp home mode.... the third gear kind. Stopped, waited a few minutes and then good to go. There is now no Gearbox Fault script, but the Engine Fault script continues to appear. Only went into "limp home mode" this one time [hopefully].

We have replaced the Throttle Body with a known good Throttle Body and no change. Still shows an Engine Fault script after about 3 miles down the road.

I can feel no loss of power or engine missing. Runs strong right up to 4k w/o any obvious problems (except the one-time Limp Home Mode episode.)

Ideas?

 

Well, I do know that when there is a transmission issue, the CEL can come on. First let me ask, does the CEL light work? Does it show on key ignition?

As for the P1000, if you haven't cleared the codes on it in awhile, the P1000 "system readiness test not completed' should have changed to the normal P1111. That is odd. I would try another OBDII reader, just to be sure communications are well between the two.

Have you had any other transmission issues or repairs/maintenance?

 

I think I found the problem. It is with the Cruise Control, but linked into the Brake Switch. Driving without the CC button activated, the screen shows no fault msgs.

I have began to dig a little deeper, but I think the answer is a new brake switch.

 

Nice catch, would not have guessed that.

 

I searched the knowledge base over at Roadfly and found the connections. They have some very good technical information posted over the years. I hate their no-mouseover format which forces you to open each post to see it's content. Difficult to read.

 

Probably have P1571 Brake Switch Malfunction.
You might need a different code reader to read 'enhanced codes'.
P0XXX codes are mandatory OBDII but
P1XXX codes are manufacturer specific and can be anything.

 

So far replacing the Brake Pedal Switch has cured the Engine Fault dash script.

Problem: The dash screen was showing an "ENGINE FAULT" script; but there was NO "Check Engine" light. This occurred only when the Cruise Control button was activated. The cruise control was inoperable under these conditions.

Diagnostic: Turn off the Cruise Control button on consul. This should eliminate warning script on next start up.

Solution: Replace the Brake Pedal Switch

Logic: Apparently, the second set of the four (4) brake pedal switch contacts goes to the Cruise Control [via the ECU]. This is to deactivate CC when the brakes are applied. When this functionality is not working, because of a faulty brake pedal switch, the ECU deactivates the CC. Why the ECU presents this as an Engine Fault warning is beyond me, but that is the symptom presented.