random engine shutdown - resolved

[JeffreyM]

We have a 2008 Explorer Limited w/ 4.6 engine. We have been having random engine shutdown over the last 6 months or so. When this happens, she pulls over, turns key off and then car restarts normally. This happens maybe once or twice a month (hasn't happened when I was in the car). I've read about the issue w/ coil breakdown on the right side of the engine, but Forscan does not show any misfire DTC. The only DTC that is recorded is P0600 - Serial Communication Link Malfunction, and P2105 - Throttle Actuator Control System - Forced Engine Shutdown. From what I have read, P2105 is more of a failsafe shutdown due to something else that is potentially dangerous.
P0600 sounds like it could be a wiring issue, but there are so many components involved in running the engine, I can't guess where to start looking. I guess maybe I should just reseat the connection to the PCM and see if that helps. I would appreciate any useful insight into what else to check.

 

[Fix4Dirt]

not a 4g expert by any means, but when i hear random shut down, and that it fires back up after a tiny bit makes me think iverheatin an fuel pump... however, hiven thsi info with the po600 and the throttle actuator, i want to say maybe the TPS is giving a bad readibg? is this druve by wire or cabled?

 

[96eb96]

I passed on a nice 08' because it had tons of codes and likely major wiring issues. The codes seemed to point to one common circuit. That 2105 may have been present. The car was sight unseen (but great price) and decided not to take the risk.
One thing I know is some have brittle wires, so inspect all the wiring to the throttle body and sensors.

 

[94Eddie]

I agree with checking the wiring insulation for deterioration. This is a somewhat common problem with the 2006-2008 4th gens. The deterioration typically occurs where the wires are exposed at the ends of the looms or just into the looms. Check the wiring at the connectors going into the throttle body and anywhere else you can see a connector with exposed wiring. The best way to track down issues like this is to use real time data logging to find anomalies in the signals coming from sensors, modules etc. with a high end data scanner. This needs to be done by a skilled diagnostic technician. Don't assume that every mechanic that has a high end scan tool knows how to properly use it. Most don't.

 

[96eb96]

I agree with checking the wiring insulation for deterioration. This is a somewhat common problem with the 2006-2008 4th gens. The deterioration typically occurs where the wires are exposed at the ends of the looms or just into the looms. Check the wiring at the connectors going into the throttle body and anywhere else you can see a connector with exposed wiring. The best way to track down issues like this is to use real time data logging to find anomalies in the signals coming from sensors, modules etc. with a high end data scanner. This needs to be done by a skilled diagnostic technician. Don't assume that every mechanic that has a high end scan tool knows how to properly use it. Most don't.

True, many are just part changers. Maybe a bit above some DIY guy with a bit of knowledge.

 

[JeffreyM]

We have a 2008 Explorer Limited w/ 4.6 engine. We have been having random engine shutdown over the last 6 months or so. When this happens, she pulls over, turns key off and then car restarts normally. This happens maybe once or twice a month (hasn't happened when I was in the car). I've read about the issue w/ coil breakdown on the right side of the engine, but Forscan does not show any misfire DTC. The only DTC that is recorded is P0600 - Serial Communication Link Malfunction, and P2105 - Throttle Actuator Control System - Forced Engine Shutdown. From what I have read, P2105 is more of a failsafe shutdown due to something else that is potentially dangerous.
P0600 sounds like it could be a wiring issue, but there are so many components involved in running the engine, I can't guess where to start looking. I guess maybe I should just reseat the connection to the PCM and see if that helps. I would appreciate any useful insight into what else to check.

I'm goin g to say this has been resolved, It's been over a month w/ no more shutdowns.
I tried reseating the connections to the ECU, but that had no effect. All connections appeared clean. Also reseated the wiring connections to the transmission.
I finally decided to change the two rear COP since they are the ones known to cause issues since they are next to the main wire harness. I was going to buy new ones, then decided since I have a second Limited V8, I'd just swap in coils from the 2nd car. When I pulled the coils from her car, I found one that had a white powder where the coil attaches to the plug. Apparently some kind of corrosion causing a poor connection to the plug. It would seem the root cause of the corrosion was the known issue of water dripping from the windshield cowling onto the plug. I cleaned out the corrosion and and swapped the suspect coils to my car. Both cars are now running perfectly with no further issues.

 

[J_C]

Good!

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