Bulletin No.: PIC5920H
Published date: 06/17/2019

Preliminary Information
PIC5920H Vehicle Will Not Charge And Hybrid Loss Of Isolation
With DTC P0AA6 And/Or P1FFF P1F0E P0DAA
Models
Brand:

Model:

Model Years:

VIN:
from

to

Engine:

Transmissions:

Chevrolet

Volt

2011 - 2014

All

All

LUU

MKA

Cadillac

ELR

2014 - 2016

All

All

LUU

MKA

Opel

Ampera

2011 - 2014

All

All

LUU

MKA

Holden

Volt

2013 - 2014

All

All

LUU

MKA

Supersession Statement
This PI was superseded to update model years. Please discard PIC5920G.

Condition / Concern
Some customers may comment that their vehicle will not charge. Customers may also
comment that a Check Engine Lamp is illuminated. Technicians may find a current code
P0AA6 and / or a P1F0E set on 2011-2013 Volt or a P0DAA on 2014 Chevy Volt, Opel Ampera
or Cadillac ELR in the HPCM2. When diagnosing these DTC’S, potential causes to consider
when evaluating the vehicle are:
1. A loss of Hybrid/EV Battery Pack coolant (external or internal to the Hybrid/EV Battery
Pack)
2. A loss of high voltage isolation within the battery cells or battery sections themselves

Recommendations / Instructions
Locate the Isolation Test Resistance that is located in the HPCM 2 data list under HPCM 2 /
Data Display / Data Display / Hybrid/EV Powertrain Control Module 2 Data and note the
current value on the repair order.
Also note the Isolation Resistance from the freeze frame records in the HPCM2 for the
P0AA6, P1F0E, and/or P0DAA DTC.
Inspect Hybrid/EV Battery Pack coolant level by doing both of the following:
Note if the coolant level is low in the under hood reservoir.
Remove the drain plug for the battery to see if any water/coolant drains out, indicating
a coolant leak in the battery pack.
If necessary, refer to the Hybrid/EV Battery Cooling System Diagnostic in Service
Information.
Important: All P0AA6 failures must include an inspection of the Hybrid/EV Battery Pack
drain plug, located on the battery tray, regardless of fluid level at the Hybrid/EV Battery Pack
coolant reservoir. If any moisture is found during the drain plug inspection, contact the GM
Technical Assistance Center (TAC).
If the coolant level in the reservoir is at the proper level and there is no coolant or water
drained from the battery from the drain plug inspection, then update the HPCM2 and BECM
(Battery Energy Control Module) with the latest Calibrations in TIS-2-Web. After installing
the current calibration in each module, cycle the ignition two times waiting 2 minute in

between each ignition cycle and then check the Isolation Test resistance (in the HPCM2/ Data
Display/ Data Display / Hybrid/EV Powertrain Control Module 2 Data) and make sure the test
resistance now reads greater than 275 kOhms. If the isolation resistance now reads 275
kOhms or greater, then no further Attention is needed. If the DTC sets again, then check the
freeze frame for HPCM2 again also.
Important: If you have any moisture that is found in the battery during the drain plug
inspection or the Isolation test resistance will not go above 275 kOhms after the HPCM2 and
the BECM have been updated, please contact the Technical Assistance Center (TAC) for
further direction.

Warranty Information
For 2011- 2014 Volt/Ampera And 2014 Cadillac ELR

Labor
Operation

Description

Labor
Time

2880268*

Reprogram the HPCM2 and the
BECM.

0.6 hr

* This is a unique labor operation for bulletin use only.
This will not be published in the Labor Time Guide.

The labor code above is covered under the V oltec or
Emission warranty , coverage code: V or E
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is
resolved without completing every step, the remaining steps do not need to be performed.

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