B1325

DTC B1325

Diagnostic Instructions

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

DTC Descriptors

DTC B1325 03
- Device Power Circuit Voltage Below Threshold

DTC B1325 07
- Device Power Circuit Voltage Above Threshold

DTC B1325 4A
- Device Power Circuit Checksum Error - IPC

Diagnostic Fault Information






Circuit/System Description

The following control modules monitor the battery voltage through the battery positive (B+) voltage circuits:

* Instrument panel cluster (IPC)
* Memory seat module (MSM)
* Passenger presence system (PPS)
* Radio
* Ultrasonic parking aid (UPA)

If any of those control modules detect that the battery voltage is out of range, the module will set DTC B1325.

Conditions for Running the DTC

* The battery voltage supplied to the control modules is in the range of 7-26 volts.
* The ignition is ON.
* The engine is running.

Conditions for Setting the DTC

B1325 03

The control module detects that the system voltage is less than 9 volts for 5 seconds.

B1325 07

The control module detects that the system voltage is greater than 18 volts for 5 seconds.

B1325 4A

The instrument panel cluster (IPC) failed the power on checksum test, either due to low voltage or corrupted memory.

Action Taken When the DTC Sets

* The control module immediately disables all outputs when an out of range voltage condition has been detected, with the exception of GMLAN and the Run/Crank relay, which are disabled after a 3 minute delay.
* The setting of other DTCs is inhibited.

Conditions for Clearing the DTC

The DTC clears when the malfunction is no longer present.

Diagnostic Aids

* A high or low voltage value in multiple modules indicates a concern in the charging system.
* Overcharging with a battery charger or jump starting can cause this DTC to set.

Circuit/System Verification

1. Measure and record the voltage at the battery terminals with engine off, and again with the engine running. Verify that the battery voltage is 11-17 volts with the engine off and with the engine running.

• If the battery voltage is not within the specified range, refer to Charging System Test (Acadia or Enclave) Charging System Test (OUTLOOK). Charging System Test Charging System Test

2. Observe the scan tool Battery Positive Voltage parameter in the data list of the module setting the DTC. Verify that the scan tool displays a value that is within 2 volts of the battery voltage recorded in step 1.

• If the scan tool parameter is not within the specified range, refer to Circuit/System Testing.

3. Refer to Diagnostic Aids.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector of the module that set the DTC.
2. Verify that there is less than 1.0 ohm between the ground circuit and the negative battery terminal.

• If greater than the specified value, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp illuminates between the B+ circuit of the appropriate module and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

4. If all circuits test normal, replace the appropriate control module.

Repair Instructions

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