Eurovan keeps thinking it's in reverse gear

[EuroTec]

Try disconnecting the wire from the camera to the reverse light circuit. It may be getting a back voltage from that.... perhaps. It's the only other "variable" in the equation.
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If it ain't broke, don't fix it!

[Endopotential]

Thanks @Eurotec for that diagram.

Well, so far it's been a frustrating dead end.

I replaced both the PNP switch (or I guess more accurately called the MultiFunction Transmission Range Switch MFTRS) down by the transmission, and also the 175 relay in the center console. This didn't resolve the problem yet.

I'm at a loss where to proceed next. I guess there could be a short somewhere in the wire harness to the 175 relay such that it's constantly on?

Though I did find out along the way, to add to Jeopardy "Random Things that Won't Let a Eurovan Start" category:
- unplugging the MFTRS won't let you crank the engine and will throw a P0705
- unplugging the 175 relay also wont let you crank the engine, but no error code. God forbid this ever burned out, it would be impossible to diagnose that no start situation

I also pulled fuse #14, supposedly for the backup lights, but that threw a red "Brake" light on the dash.

Think I'll throw in the towel at this point as the van is still driveable. I may just pull out the white light bulbs for the backup lights - hopefully driving with them on at night won't attract any cops.

[EuroTec]

Q: What happens when you pull the connector at the switch on the transmission? Just curious.

I'm thinking a problem with the park/neutral relay as well. Remove it and the lights should go out. Then you know the voltage source is indeed coming through the relay.

This sounds silly I know but take the relay and smack it against your palm a few times, just to jar it around a bit, then plug it back in and test. If the lights are out it was stuck. I've used this method to find a stuck relay or two in my time. Worth a try for the sake of diagnostics.

Anyway, here's a reverse light circuit wiring diagram for a 2002 Eurovan.

_________________
If it ain't broke, don't fix it!

[gesoffen]

As a startign point, I'd suggest cleaning/inspecting the connector that plugs into the neutral safety switch. I noted mine was gunked up due to a transmission fluid leak from the switch oring and resulted in some odd gear indications on the dash after I replaced the o-ring. I'd also recommend inspecting the wire harness.

My next step would be to do some pinout testing on the connector - I believe Eurotech had a good write up on the various pin-to-pin connections, perhaps in his documentation on his 5 speed conversion?

Failing those two, perhaps the ECU and/or the TCM need to be recoded to talk to each other correctly? Total shot in the dark though....

[Endopotential]

No, I've had the stereo with the backup camera for a couple years and it's been working fine until this latest glitch. It also wouldn't explain why the reverse lights stay on.

[TheOneTrueQuux]

[Endopotential]

I've got a 2002 Weekender. After a prolonged headache fixing a fried ECU, it now drives fine.

The only weird glitch is that it seems to keep thinking it's always in reverse regardless of what I select, in that the rear backup lights are always on. I also installed a new stereo head unit where the reverse camera is triggered off the rear light, and that camera is now perpetually on.

I just replaced the park neutral switch down by the transmission, to no avail. BTW I didn't realize there would be a gush of transmission fluid during the swap, so off to chase that tangent soon.

I'm guessing I should replace the 175 reverse relay in the center console next? Or any other thoughts?