[MrSnuzzy336]

Hello, today I went out for a drive, parked my car, and when I came back I was met with the lovely "Service High Voltage Charging System" message, which I have never received before. My OBD scanner pulled 3 codes: P1e00, P0aa6, P1fff. All coolant levels appeared to be good and it drives well on the gasoline engine. I have a hunch it's a coolant sensor but any other ideas would be nice.

Thanks,

 

[bentbiker]

Did you make a conscious decision NOT to install the WOT defeat plug? Since a failed wiring harness is another possibility, have you checked to make sure it's plugged into the sensor and that there is no obvious sign of rodent damage or nesting material?

 

[MrSnuzzy336]

Did you make a conscious decision NOT to install the WOT defeat plug? Since a failed wiring harness is another possibility, have you checked to make sure it's plugged into the sensor and that there is no obvious sign of rodent damage or nesting material?

Nope, I have never heard of the WOT defeat plug until now. Either way, I will have to go to the dealer to have it reprogrammed.

 

[bentbiker]

Either way, I will have to go to the dealer to have it reprogrammed.

I don't know if you've read everything on this, but some people have been charged hundreds of dollars multiple times to repeatedly re-flash the software on the two modules. Just paying the dealer to do the re-flash without knowing the real cause is a recipe for continuing problems.

 

[jbakerjonathan]

Just to clarify, the wiring harness potential problem occurs only on those 2011 and 2012 Volts that had the recall performed. Very late 2012s and all subsequent model years had the factory wiring.

To the OP, read this: WOTs COOLANT LEVEL SENSOR / SERVICE HIGH VOLTAGE...
and my post therein: #192
I've had the WOT sensor installed for over four years without a problem. The dealer has serviced my Volt at least twice while the sensor was installed and was unaware of its existence.

 

[bentbiker]

Just to clarify, the wiring harness potential problem occurs only on those 2011 and 2012 Volts that had the recall performed.

You are thinking of one particular issue causing harness failure, but the wire going to the sensor can fail for a number of reasons, regardless of the year.

 

[MrSnuzzy336]

Got it back today, the dealer pulled the codes, saw the service bulletin, re-flashed, tested for a few days and the sensor is reading properly. I double-checked with them that it wouldn't come back and they assured me they would cover the cost if it needs any more work. I will update if there are any problems, thanks all.

 

[16falcon]

My 2013 got reflashed almost a year ago and I have not had a reoccurrence of the SHVCS since then. I still have my original factory coolant sensor.

 

[jbakerjonathan]

You are thinking of one particular issue causing harness failure, but the wire going to the sensor can fail for a number of reasons, regardless of the year.

Yes, I believe that there is a picture posted in the forum of a broken (corroded) wire at the connector. It might not have been the connector for this sensor, but, it proves your point.