Circuit Description
The body control module (BCM) monitors the load control circuit for opens, shorts to ground, and shorts to voltage.
The circuit starts at the BCM and travels to the instrument panel (I/P) fuse panel where the circuit splits to supply power for the heated seat switch and HVAC control head for the rear defog relay driver.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B1507 High Power Control Circuit Low |
| • | DTC B1508 High Power Control Circuit High |
Conditions for Running the DTC
| • | This DTC shall run only if the voltage to the BCM is between 9-16 volts. |
| • | The ignition must be in the ON position. |
| • | This DTC shall not set during BCM programing and configuration changes. |
| • | This DTC shall not set if any communication codes are set. |
Conditions for Setting the DTC
A DTC B1507 or 1508 will set when the load control circuit does not react as commanded. A DTC B1507 will set if the BCM enables the control circuit and the output does not react within 400 ms. A DTC B1508 will set if the BCM disables the control circuit and the output does not react within 400 ms.
DTC | Condition |
|---|---|
B1507 | Low Voltage on Control Circuit |
B1508 | High Voltage on Control Circuit |
Action Taken When the DTC Sets
The BCM sets a DTC and disables the following DTCs:
| • | DTC U1096 |
| • | DTC U1255 |
| • | DTC U1300 |
| • | DTC U1301 |
The BCM illuminates the service vehicle soon (SVS) indicator.
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 | Yes | No |
|---|---|---|---|
Schematic Reference: Body Control System Schematics Connector End View Reference: Master Electrical Component List | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Does the scan tool indicate that DTC B1482 is current? | Go to Testing for Intermittent Conditions and Poor Connections | Go to Step 3 |
3 | Test the load control circuit of the BCM for an open, a short to voltage, or a short to ground. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | Go to Step 6 | Go to Step 4 |
4 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs. Did you find and correct the condition? | Go to Step 6 | Go to Step 5 |
5 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | Go to Step 6 | -- |
6 |
Does the DTC reset? | Go to Step 2 | System OK |
