A/C cuts off, then gas motor stalls. Yellow wrench

[Mooresworld]

For the past 4 months, my 2013 C-max has had the gas part of the engine stop running while driving. The electric continues enough to get off the road, until the battery is depleted. This is often accompanied by a yellow wrench alert, but not every time. The shutdown is preceded by the A/C cutting off, weakly blowing warm air while another fan under the dash runs very loudly. 

 

Once I limp over to the side of the road on battery power, if I turn off the ignition and turn it back on, it returns to normal operation (until the next incident, which could be days or weeks later).

 

I purchased an OBD2 scanner (Autel MaxiLink ML529) and ran an OBD scan immediately after the yellow wrench shutdown. No codes were found. The Ford mechanics also found no stored codes.

 

I've taken it in to the dealer, but so far, they haven't been able to pull any codes after one of these events. They've updated the PCM to the latest version, but that hasn't solved the problem. They are stumped. 

 

Has anyone had this problem and found a solution? 

Edited February 13, 2019 by Mooresworld

[plus 3 golfer]

It's amazing that there are no stored codes for the Yellow wrench.  The issue must not be deemed to be "affecting" emissions because the engine shuts off.  Upon restart, the monitors are not detecting any issue.  I assume once you turn the car off and back on, everything is OK? You never got a "stop safely now" message?

 

A couple of thoughts:

 

You could get the ForScan App for a smartphone and an ODBII ELM327 module so that when you pull off the road with car still on you can check for DTCs.

 

It almost sounds like the modules believe that the car should be / has been has been turned off.  There are many fail safe checks which allow the car to be driven on EV so you can get off road.  Once stopped, you can't drive any further until you turn car off than back on assuming issue is still present?

 

How long is the AC turned off before the Internal Combustion Engine won't run?   How do you know when ICE is off?  Does other equipment still work before turning car off? wipers, radio, turn signals and so forth.  

 

I will look at the ICE fail safe stuff in Service Manual.  For example, if car overheats, there are several things that happen to prevent damage to ICE like shutting down the AC to allow cooler air to the radiator and ultimately not allowing ICE to run.  Perhaps, it's as simple as a few bad sensors causing issue.  Next time it happens put HVAC into full heating mode as soon as you notice warm air instead of cool air.

 

[cr08]

Wild ass guess from me but sounds like the dealer didn't do their job if they weren't able to pull any codes and couldn't do any further diagnosing. A yellow wrench scenario, at ABSOLUTE minimum, should have some 'pending' codes after the fact if not full blown stored DTC's.

 

Plus 3 Golfer brought up all very good points especially the suggestion to use an OBD dongle and the ForScan app for some potential diagnosing on your end. If that's not immediately available, even having a place like Autozone try to pull codes may not be a bad idea. At the very least if a generic off the shelf scantool can pull some codes where the dealer couldn't, it will at least provide even a tiny bit of direction on what is going on.

[Mooresworld]

It's amazing that there are no stored codes for the Yellow wrench.  The issue must not be deemed to be "affecting" emissions because the engine shuts off.  Upon restart, the monitors are not detecting any issue.  I assume once you turn the car off and back on, everything is OK? You never got a "stop safely now" message?

 

A couple of thoughts:

 

You could get the ForScan App for a smartphone and an ODBII ELM327 module so that when you pull off the road with car still on you can check for DTCs.

 

It almost sounds like the modules believe that the car should be / has been has been turned off.  There are many fail safe checks which allow the car to be driven on EV so you can get off road.  Once stopped, you can't drive any further until you turn car off than back on assuming issue is still present?

 

How long is the AC turned off before the Internal Combustion Engine won't run?   How do you know when ICE is off?  Does other equipment still work before turning car off? wipers, radio, turn signals and so forth.  

 

I will look at the ICE fail safe stuff in Service Manual.  For example, if car overheats, there are several things that happen to prevent damage to ICE like shutting down the AC to allow cooler air to the radiator and ultimately not allowing ICE to run.  Perhaps, it's as simple as a few bad sensors causing issue.  Next time it happens put HVAC into full heating mode as soon as you notice warm air instead of cool air.

 

 

Wild ass guess from me but sounds like the dealer didn't do their job if they weren't able to pull any codes and couldn't do any further diagnosing. A yellow wrench scenario, at ABSOLUTE minimum, should have some 'pending' codes after the fact if not full blown stored DTC's.

 

Plus 3 Golfer brought up all very good points especially the suggestion to use an OBD dongle and the ForScan app for some potential diagnosing on your end. If that's not immediately available, even having a place like Autozone try to pull codes may not be a bad idea. At the very least if a generic off the shelf scantool can pull some codes where the dealer couldn't, it will at least provide even a tiny bit of direction on what is going on.

Thank you both for your suggestions. Once I limp over to the side of the road on battery power, if I turn off the ignition and turn it back on, it returns to normal operation (until the next incident, which could be days or weeks later). I purchased an OBD2 scanner (Autel MaxiLink ML529) and ran an OBD scan immediately after the yellow wrench shutdown. No codes were found. The Ford mechanics also found no stored codes.

 

I know the ICE only shuts down because my instrument panel is set to show ICE/electric gauges.

 

The A/C seems to shut down anywhere between immediately before ICE failure to 30 seconds before. The failure can happen after driving for hours or minutes, so far, in cool weather.

 

The Ford mechanic pulled rear panels to check for wiring problems and found none.

Edited February 13, 2019 by Mooresworld

[plus 3 golfer]

I don't believe the ML529 will scan all of the Ford modules on the HighSpeed-Can and likely none on the MediumSpeed-Can.  If there was a DTC deemed to be "emissions related", the code must be stored (EPA regs).  But many codes, like for a stability control issue message I got one time, was not stored.  So, you may need to scan the car when the message is being displayed to see the code (if any).  I don't recall anywhere in the service manual when a code is NOT thrown for a yellow wrench.  One other place to look is here although I have yet to see anywhere what codes the ETM stores.

[plus 3 golfer]

I can't find anything specific in the manual about fail safe operations other than there are Limited Operating Strategies to allow the driver to safely operate the car for many potential conditions that could arise.  

 

With ForScan and this OBDLink module (the cheap modules will likely lose connection frequently) one can record PID data for hours at a time without interuption to capture data when the AC shuts down and yellow wrench appears.  Before shutting down the car, one stops the scanning, saves the data.  One can then upload to excel and analyze what happened around the time the issue occured.

 

Other than the dealer doing the same troubleshooting by monitoring realtime data, the issue may not be resolved until there is a "hard" failure.

 

Did the dealer tech call Ford as the fact that the A/C shuts down seems to be significant, IMO to when the car goes into a LOS. I assume you haven't seen this LOS with A/C off.

[Mooresworld]

Took it to another Ford dealer today. They discovered liquid (water intrusion they call it) in the battery compartment. Both batteries, they say. They're removing the hybrid battery (with my permission; $450 labor estimate for the inspection). Hoping this explains what's been going on. I don't know how the water could have gotten in. I've had no spills in the cargo area. I would like to think this will be covered by the hybrid part warrantee, but because of the water intrusion, the mechanic is skeptical.

Also, this mechanic DID get a power disconnect code on the pin point test, which they say requires the hybrid battery removal for proper diagnosis.

Edited February 15, 2019 by Mooresworld

[cr08]

Have them or either you check the passenger side headliner. The washer fluid hoses for the hatch run back there along the passenger side. This hasn't been a TOO common occurrence but the few people who have had water intrusion issues with the battery seem to have had this line leak and cause it.

[plus 3 golfer]

That likely explains it.  The AC compressor is powered by the HVB and ICE will shut down for HVB issues.  I doubt the HVB will be covered if the washer line hose caused the issue as you are well past the 3/36 B2B although maybe CA is different.  If it is water intrusion but not the washer line, perhaps your comprehensive insurance will cover it. 

[Mooresworld]

Thanks for the washer hose idea! I've passed it on to the mechanic to check.

[Mooresworld]

UPDATE 4-23-2019:

After more that 8 weeks at the dealer, Ford Engineering stepped in and solved the problem by replacing the transmission! Because it's considered part of the hybrid system, which is under warranty here in California for 150,000 miles, there was NO CHARGE!

It drives like new, despite the 125,000 miles I've put on it.

PS The water in the battery compartment came from a missing seal from the bumper I replaced. That's the body shop's fault. Unrelated to the engine stalling issue.