Battery Shorted and High Current Array Blown

[mwilk012]

Bypass? What bypass?
What exactly did you do? “Something shorted in the process” is what you need to figure out. Did you short the positive lead against the body?

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[cosunrise]

Thanks. I have the 2.0T, so I'm not sure if the wiring is the same as the 3.6? I did come across another thread you posted regarding the rad fan control circuit that will be helpful in checking continuity. Curious whether there is always signal on that wire or only when the PCM is calling for cooling fan over 200F?

In related news, I did replace the EHCP unit with a junkyard part and the power steering code is cleared. If both rad fan and power steering refused to clear, I'd feel more confident that the PCM is at fault...

I went ahead and bit the bullet on a new Mopar MGU and installed that. Need the dealer flash still before it will do anything, of course.

 

[cosunrise]

Bypass? What bypass?
What exactly did you do? “Something shorted in the process” is what you need to figure out. Did you short the positive lead against the body?

When I originally posted, I didn't realize that the eTorque doesn't have the AUX battery. (There's a lot of contradictory info out there on the forum about this topic.) Anyway, I've visually confirmed now that I don't have one, but I was attempting to separate and charge the AUX battery on it's own, based on comments in other "no start" threads.

Yes, the most plausible scenario is that I shorted the positive to body ground, or positive cable to battery negative?

 

[cosunrise]

Turns out the 2.0T is not wired the same as the 3.6 and uses the GPEC5 instead of GPEC2A PCM. Thanks to RPM fan controls for providing a wiring diagram in their install instructions because I pored over the Service Manual wiring diagrams to no avail trying to find the radiator fan. Turns out pin 1 on the C1 (forward) connector is the Radiator Fan at the 2.0T's PCM:

So... checked and found continuity between PCM and the rad fan control pin at the fan harness.

Subsequently, found that in the Powertrain module in Jscan, there is a function to activate the radiator fan and run it at various speeds. I was able to do this confirming that the rad fan runs and that the PCM is able to send a control signal which activates the fan.

I feel like I'm missing something big here. Clearly, the circuit is not "open" as the P0480 code indicates if I can activate it from the PCM via Jscan.

FWIW I tried and failed to get the coolant temp over 200F to see if there was a change in voltage on the control wire from the PCM. Couldn't get her above 192F with the AC running.

 

[Danjeepman57]

I installed a new set of steps on my Wrangler today.

 

[gato]

In related news, I did replace the EHCP unit with a junkyard part and the power steering code is cleared.

Good news. Second battle won. Seems like you just need to figure out the radiator fan code.

Keep at it, you are almost back to normal.

Glad to see you also sourced the MGU. I don't have eTorque, so not sure how that entire system works.

 

[mwilk012]

When I originally posted, I didn't realize that the eTorque doesn't have the AUX battery. (There's a lot of contradictory info out there on the forum about this topic.) Anyway, I've visually confirmed now that I don't have one, but I was attempting to separate and charge the AUX battery on it's own, based on comments in other "no start" threads.

Yes, the most plausible scenario is that I shorted the positive to body ground, or positive cable to battery negative?

Another case of the auxiliary battery misinformation causing harm. Sorry you had to be on the receiving end of this. You’re going to spend a lot of money replacing expensive parts, the odds of everything being fried is low.

 

[cosunrise]

I agree and don't want to throw parts at it, although it did seem plausible that EHPS, Rad Fan and MGU could be fried since all feed directly off the high current array which was fried.

CAN Bus seems good, ~2.3v AND 2.2v on pins 6 and 14 of ODB/SGW bypass.

She's at the dealer today for MGU programming- any recommendations for next steps troubleshooting?

 

[roaniecowpony]

I agree and don't want to throw parts at it, although it did seem plausible that EHPS, Rad Fan and MGU could be fried since all feed directly off the high current array which was fried.

CAN Bus seems good, ~2.3v AND 2.2v on pins 6 and 14 of ODB/SGW bypass.

She's at the dealer today for MGU programming- any recommendations for next steps troubleshooting?

If the radiator fan isn't working, start at the temperature sensor and work your way toward the PCM. Also, the fan won't come on until it gets up there around 215-220, unless you turn on the AC.

 

[Terrymo]

When I originally posted, I didn't realize that the eTorque doesn't have the AUX battery. (There's a lot of contradictory info out there on the forum about this topic.) Anyway, I've visually confirmed now that I don't have one, but I was attempting to separate and charge the AUX battery on it's own, based on comments in other "no start" threads.

Yes, the most plausible scenario is that I shorted the positive to body ground, or positive cable to battery negative?

Agreed. As you discovered this topic has become overly complicated and confusing. Rather than suggesting people count battery cables or reservoirs or distinguish between an alternator and a belt start generator, people should simply be told to look under the Jeep. If you see this object outlined in red you have an etorque battery under the Jeep and an empty auxiliary battery box in the fender well. Sorry this happened to you.

 

[alphawolff]

I agree and don't want to throw parts at it, although it did seem plausible that EHPS, Rad Fan and MGU could be fried since all feed directly off the high current array which was fried.

CAN Bus seems good, ~2.3v AND 2.2v on pins 6 and 14 of ODB/SGW bypass.

She's at the dealer today for MGU programming- any recommendations for next steps troubleshooting?

Did you replace the 48v battery at all? I see you mention EHCP, but I have no idea what that's referring to.

Here's the diagnostic flow for the DC converter DTC.

 

[cosunrise]

If the radiator fan isn't working, start at the temperature sensor and work your way toward the PCM. Also, the fan won't come on until it gets up there around 215-220, unless you turn on the AC.

I can check the temp sensor, but watching the coolant and ambient temps on Jscan, they seem accurate and steady.

Dealer is done, MGU is programmed and all MGU codes cleared successfully.

Still have the rad fan code P0480 and now a bunch of ABS/speed sensor-related codes:

C0037-62 (left rear wheel speed sensor-signal compare failure)
C0031-1D (left front wheel speed sensor - circuit current out of range)
U0415-00 (invalid data received from anti-lock brake system (abs) control module)
U0418 (implausible data received from brake system control module)
P1DB6-00 (vehicle speed signal performance)
U1412-00 (implausible vehicle speed signal received)

Both LR and LF sensors were brand new already (literally hadn't left the driveway yet, other than today's trip to the dealer). But, you never know and I had a set of spares in the garage, so I swapped out the left front and left rear sensors. No change.
Jscan shows no voltage on LF but the other three seem normal. Visual inspection shows no wire damage from the sensor up to the firewall, where I lose it.

 

[cosunrise]

Did you replace the 48v battery at all? I see you mention EHCP, but I have no idea what that's referring to.

Here's the diagnostic flow for the DC converter DTC.

Sorry, sticky fingers/autocorrect or something. EHPS is what I meant to say. Not sure where EHCP came from!

I did not replace or test the 48v battery. Everyone on the forum seems to say leave it alone, so I did.

 

[alphawolff]

I can check the temp sensor, but watching the coolant and ambient temps on Jscan, they seem accurate and steady.

Dealer is done, MGU is programmed and all MGU codes cleared successfully.

Still have the rad fan code P0480 and now a bunch of ABS/speed sensor-related codes:

C0037-62 (left rear wheel speed sensor-signal compare failure)
C0031-1D (left front wheel speed sensor - circuit current out of range)
U0415-00 (invalid data received from anti-lock brake system (abs) control module)
U0418 (implausible data received from brake system control module)
P1DB6-00 (vehicle speed signal performance)
U1412-00 (implausible vehicle speed signal received)

Both LR and LF sensors were brand new already (literally hadn't left the driveway yet, other than today's trip to the dealer). But, you never know and I had a set of spares in the garage, so I swapped out the left front and left rear sensors. No change.
Jscan shows no voltage on LF but the other three seem normal. Visual inspection shows no wire damage from the sensor up to the firewall, where I lose it.

With key on check for voltage at those speed sensor connectors. Should be equal to B+, so 12v or so. If you aren't getting voltage trace back to ABS to verify circuit integrity. If missing voltage and all OK your ABS module is shot.

WARNING; DO NOT REPLACE YOUR ABS! We currently cannot program new ones. This has been an issue for over a year now, and engineering still hasn't figured it out. You'll just have to deal with it for now.

 

[cosunrise]

With key on check for voltage at those speed sensor connectors. Should be equal to B+, so 12v or so. If you aren't getting voltage trace back to ABS to verify circuit integrity. If missing voltage and all OK your ABS module is shot.

WARNING; DO NOT REPLACE YOUR ABS! We currently cannot program new ones. This has been an issue for over a year now, and engineering still hasn't figured it out. You'll just have to deal with it for now.

I have 11.9 volts at the ABS sensor.

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