Service Information

Volt

DTC P1EA9

Diagnostic Instructions

•	Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

•	Review Strategy Based Diagnosis for an overview of the diagnostic approach.

•	Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC P1EA9: 14 V Power Module System Low Voltage

The 14 V power module, also called the accessory DC power control module, monitors its 14 volt circuit when it is enabled. This DTC sets when the 14 volt circuit in the 14 V power module is below this minimum level at the time it is enabled. 14V power module module functions will run only when an APM enable message from the hybrid powertrain control module is active on the serial data circuit.

Conditions for Running the DTC

The hybrid powertrain control module commands the 14 V power module to begin charging.

Conditions for Setting the DTC

The 14 volt circuit at the 14 V power module is below 7.0 volts when attempting to begin charging.

Action Taken When the DTC Sets

•	DTC P1EA9 is a Type C DTC.

•	The 14 V power module will not allow 14 volt conversion to begin in this condition.

Conditions for Clearing the DTC

•	DTC P1EA9 is a Type C DTC.

•	The 14 volt circuit at the 14 V power module is above 7 volts.

Diagnostic Aids

The 14 V power module is protected by a 200 amp in-line mega-fuse. The output current of the 14 V power module is lower than the fuse rating.

Reference Information

Electrical Information Reference

•	Circuit Testing

•	Testing for Intermittent Conditions and Poor Connections

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Testing

Remove the B+ harness connector X4 at the K1 14V power module.
Connect a test lamp between 12 volt battery positive and the K1 14 V power module connector X4 at the module.
Vehicle ON, observe the Low-Voltage Circuit Voltage parameter in the 14 V Power Module data list. The parameter should be within 0.5 volts of the actual 12 volt battery voltage.

⇒	If the voltage is not within the specified range, replace the K1 14V power module.

Vehicle OFF, remove the positive connection at the 12 volt battery.
Measure the resistance between the X4 connector and the battery positive connection.

⇒	If the resistance is greater than 1.0 ohm, repair the high- resistance condition in the 12 volt circuit.

⇒	If the resistance is less than 1.0 ohm, replace the battery positive cable - B+ APM Module to Battery Fuse Block.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

•	Battery Positive and Negative Cable Replacement for B+ APM Module to Battery Fuse Block.

•	Control Module References for Accessory DC Power Control Module, also called the 14 V power module, replacement, programming and set-up