For 1990-2009 cars

### Circuit Description

The control modules on this vehicle monitor the battery voltage through the battery positive voltage circuits. This vehicle has multiple modules that will set this DTC. For more information on which modules , Refer to Diagnostic Trouble Code (DTC) List - Vehicle.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1325 Device Power Circuit

This vehicle has DTCs which include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description.

DTC Symptom | DTC Symptom Descriptor
--- | ---
03 | Voltage Below Threshold
07 | Voltage Above Threshold

### Conditions for Running the DTC

The voltage supplied to the control modules are in the range of 7-26 volts.

### Conditions for Setting the DTC

#### B1325 03

• | The control module detects a system voltage below the calibrated value usually 9.0 volts.

• | The above condition is present at least 5 seconds.

#### B1325 07

• | The control module detects a system voltage above the calibrated value usually 18.0 volts.

• | The above condition is present at least 5 seconds.

### Action Taken When the DTC Sets

• | The control module immediately disables all outputs when a out of range voltage condition has been detected, with the exception of GMLAN and run/crank relay that are disabled after a 3 minute delay.

• | The setting of other DTCs is inhibited.

### Conditions for Clearing the DTC

• | A current DTC clears when the malfunction is no longer present.

• | A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

### Diagnostic Aids

If the IPM reports DTC B1325 03 and responds to the scan tool with DTCs and Data, chances are that there is NOT a problem with the battery positive voltage and ground circuits of the IPM. If the IPM reports DTC B1325 03, and the remote control door lock receiver (RCDLR) reports a DTC B1440, and the IPM communicates with the scan tool, try to operate the steering wheel controls and standard cruise stalk switches. If they do not operate, test the remote radio control head ACC supply voltage circuit on IPM connector C1 terminal 25 for a short to ground.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Starting and Charging Schematics Connector End Views: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go To Diagnostic System Check - Vehicle
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With a scan tool, observe the Battery Voltage Signal parameter in the data list of the module setting the DTC.

Is the Battery Voltage Signal parameter displayed in the specified range?

9-18V

Go to Step 3

Go to Step 4

3 | Is the DTC set as a current DTC? | -- | Go to Step 7 | Go to Testing for Intermittent Conditions and Poor Connections
4 |

1. Disconnect the harness connector of the module setting the DTC.
2. Measure the voltage between the battery positive voltage circuit at the module harness connector and a good ground.

Is the measured value in the specified range?

9-18V

Go to Step 6

Go to Step 5

5 | Test the battery positive voltage circuit for the following:

• | A short to ground

• | An open

• | A high resistance

Refer to Circuit Testing.

Did you find and correct the condition?

--

Go to Step 9

Go to Charging System Test

6 | Test the all of ground circuits of the module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 7
7 | Inspect for poor connections at the harness connector of the affected module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | -- | Go to Step 9 | Go to Step 8
8 | Replace the affected module. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | --
9 | Operate the system in order to verify the repair. Did you find and correct the condition? | -- | System OK | Go to Step 2