Circuit Description
The systems under controlled power are supplied voltage through the controlled power relay. The high power control output is grounded whenever the body control module (PZM) is awake, and for 15 minutes after the ignition switch is turned to the LOCK position. After 15 minutes elapse, the low power driver output turns ON. The low power driver output can supply up to 2 AMP for up to 3 days. If the PZM detects that more than 2 AMP are needed, the PZM wakes up and turns ON the high power control output.
The PZM measures the voltage at the low power driver output every 300 ms while the PZM is in low power mode.
Conditions for Setting the DTC
The low power driver output (CKT 2540) is grounded after 2 consecutive monitoring cycles.
Action Taken When the DTC Sets
The PZM turns the controlled power output OFF until the state of the ignition changes or the PZM wakes up.
Conditions for Clearing the DTC
| • | The ignition state changes or the PZM wakes up and the condition is no longer present. DTC B1972 changes to history. |
| • | A history code clears after 50 consecutive ignition cycles if the condition is not longer present. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Body Control Module Diagnostic System Check performed. | -- | Go to Step 2 | |
2 |
Is the resistance less than the specified value? | 5 ohms | Go to Step 3 | Go to Step 4 |
3 | Repair the short to ground in CKT 2540 (ORN). Is the repair complete? | -- | -- | |
4 | Replace the PZM. Refer to Body Control Module Replacement . Is the repair complete? | -- | -- |
