P1A07

DTC P1A07

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC P1A07
- Buffered +5V Out of Range




Circuit/System Description

The battery energy control module (BECM) monitors the internal +5V reference for a out of range condition.


Conditions for Running the DTC

The engine is running, and the 12V input l to the BECM is greater than 9 volts.


Conditions for Setting the DTC

The BECM detects the internal +5V reference circuit is less than 4.7 volts for greater than 3.7 seconds.


Action Taken When the DTC Sets

The DTC sets, does not affect hybrid operation.


Conditions for Clearing the DTC

The BECM detects the internal +5V reference circuit is greater than 4.7 volts.


Reference Information
Schematic Reference

Hybrid Energy Storage Schematics ()
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information


Circuit/System Verification

Caution: To help avoid personal injury, additional precautions must be taken prior to working on the generator control module or the generator starter. After removing the 36V battery cables from the generator battery, remove both engine wiring harness connectors from the generator control module. Wait at least 5 minutes and then remove the generator control module cover. Verify voltage levels at all 36V, 12V, and 3-phase connections, are less than 3 volts using a DMM before proceeding.


Caution: To help avoid personal injury, be careful when working in the vicinity of the generator battery disconnect control module. Internal components will still be live, 36V potential, even when the cover has been opened or removed.


If the DTC occurs with P0AC0, P0AC1, P1A48 then the failure this diagnostic detects may have been the root cause of other current sensor DTCs that may have set.


Circuit/System Testing

1. Verify the DTC is set as current. If other DTCs are set diagnose those first.
2. Disconnect BECM C1. Refer to Hybrid Battery Service Disconnect/Connect ().
3. Disconnect the current sensor harness.
4. Test for greater than 100k ohms between terminals 9 and 10.

• If less than specified value, replace the harness.

5. Test for less than 1.0 ohm between terminal 9 and terminal B and between terminal 10 and D.

• If greater than specified value, replace the harness.

6. If the circuits test normal, replace the BECM.



Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.


Control Module References (Programming and Relearning) for BECM replacement, setup, and programming