My daily driver D2 has done this three times now, twice on Sunday and once today. Given the small sample size its hard to narrow stuff down but here are the things that were the same: I have been sitting in neutral with the parking brake pulled after having driven for at least 10 minutes (More like an hour on Sunday but 10 minutes today), and the truck just dies out of no where. First tine was in a driveway waiting for food, second was while taking a 15 minute power nap at a truck stop and third was while running into my place of work for a check. Car was sitting for maybe 5-10 minutes in neutral with e brake pulled before shutting off. No issues starting back up.

I had written that ^ before heading home from class and it did it again. This time it had been on and driving for 4 or 5 minutes when I parked and left it running, but chose to leave it in park to see if that had any affect. It was in park for probably 2 minutes while I was getting something out of a friends car and was still running when I hopped back in. I put it in reverse almost immediately and noticed it died, though I am not confident if it died before, during, or after the shift to reverse from park. It had a handful of codes, but some had been addressed and not cleared so I just cleared them all and will update if it throws any new codes it didn't have before this started happening. Has anyone dealt with this issue before?

One other detail I will add, I tend to park in neutral with the handbrake up, and have done so in this disco for the year I've owned it and for the last 6+ years in my other. The past month or two however, this d2 has had issues with the key not wanting to come out all the way, but I quickly found that if put it in park and turned the key to the run position, I could go to turn the key back and take it out no issues. I have been leaving it in park when I shut off so long as I remember since that started. No clue if its related but since it seemed to happen when shifting out of park today I wondered if they were related.

 

The codes should tell you, but it sounds like a failing sensor.

 

Pulled codes driving to class this morning and only had one: P0102, signal too low at MAF. I’m going to order one and for the time being swap this one with my trail rigs since it hasn't ever had a sign of failing, and see if it does it again.

IIRC these are finicky and only like certain brand MAFs, but have never had one go bad so don’t know for sure. Is that the case?

 

should run fine with the MAF unplugged. Will throw a code but should run without dying.

 

Also disconnect and reconnect all of the connectors between the MAF sensor and the ECU. Corrosion on the connector contacts could be the problem. The disconnect/reconnect will scrape through any corrosion. That will sometimes be the whole problem.

 

Truck runs fine as is with this MAF plugged in. The only issue I have had is the shutting off issue like I mentioned, but I'm confident it's only an issue when idling in park or neutral after driving. I have to go to work super early in the mornings so to warm up the cab I usually idle it for 5-10 mins. Only time it has done this is after driving it. That’s why I was surprised to see MAF code, figured that would have gave it a rough idle.

 

MAF won’t cause it to “die” I don’t believe, have never seen that. And if it did, it would sputter, then die. Which indicates fuel related.

Sounds exactly like a CPS - crankshaft position sensor. Ignition related. Like turning off the switch when it dies, right? The CPS causes this exact symptom: dying when parked, idling. They heat up, car dies. Starts of very intermittent, eventually gets worse, then gets worse, eventually completely fails. Sometimes they will not restart immediately, when my last one failed on a D2, it would restart immediately.

Also a comment on the original post. I do not understand your “in park vs in neutral” thing. Just put the car in Park ? Should have no bearing on anything really. There is no difference to the truck sitting idling in park vs sitting idling in neutral. Parking brake on or off. What is your rationale there?

 

Have you checked the Bosch IAC motor? They can get nasty and stick completely causing the idle up/down function to be INOP. Remove it and spray it with some good carb cleaning spray. The metal piece inside should rotate freely when you shake it.

 

I’ve dealt with CPS failure in my other disco before, but in that situation it would consistently start, run for 10-15 minutes and die, and then would turn over but not start until cool. I did not know they sometimes could start to fail and still restart immediately so I’ll keep that in mind.

I brought up the parking in neutral thing in case it could be something XYZ related and the truck couldnt tell what gear it was in, but I was not sure. I just have a habit of not leaving the vehicle in park from offroad trips. I’d much rather put stress on the big drum brake on the t case than on the parking pawl, espicially with a big heavy rig and parking on a hill.

 

engage parking brake while in gear, come off brake to confirm engagement and the put in park. then zero stress on parking pawl but you have a backup in case one fails...