Circuit Description
The body control module (BCM) monitors the battery voltage through the battery positive voltage circuits.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC B1325 Device Power 1 Circuit
This vehicle has DTCs that include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle DTC Information.
DTC Symptom | DTC Symptom Descriptor |
|---|---|
03 | Voltage Below Threshold |
07 | Voltage Above Threshold |
Conditions for Running the DTC
The voltage supplied to the BCM is in the range of 7-26 volts.
Conditions for Setting the DTC
B1325 03
Sets if the BCM detects a system voltage below 9 volts and the condition is present at least 5 seconds.
B1325 07
Sets if the BCM detects a system voltage above 18 volts and the condition is present at least 5 seconds.
Action Taken When the DTC Sets
| • | The BCM immediately disables all outputs when a high voltage condition was 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. |
Step | Action | Values | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Schematic Reference: Control Module References in Computer/Integrating Body Systems Connector End View Reference: Computer/Integrating Systems Connector End Views in Computer/Integrating Systems | ||||||||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||
2 |
Is the Battery 1 parameter displayed in the specified range? | 9-18 V | 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 in Wiring Systems | ||||||
4 |
Is the measured value in the specified range? | 9-18 V | Go to Step 6 | Go to Step 5 | ||||||
5 | Test the battery positive voltage circuit for the following:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 9 | Go to Battery Inspection/Test | ||||||
6 | Test the all of ground circuits of the module for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. 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 in Wiring Systems. 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 in Computer/Integrating Systems 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 | ||||||
