Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
DTC Descriptor
DTC B1390: Device Voltage Reference Input CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Battery Positive Voltage (BCM C1-51) | B1390 | B1390 | -- | B1390 |
Battery Positive Voltage (BCM C1-52) | B1390 | B1390 | -- | B1390 |
Ground (BCM C1-19) | -- | B1390 | -- | B1390 |
Ground (BCM C1-17) | -- | B1390 | -- | B1390 |
Circuit/System Description
The body control module (BCM) has an internal precision battery voltage sensor connected to dedicated battery positive voltage from terminal C1-51 and dedicated ground terminal C1-19. The BCM then compares the sensors voltage to the battery positive voltage from terminal C1-52. DTC B 1390 will set if these voltages are different by greater than 2 volts.
Conditions for Running the DTC
This DTC will run only if the BCM has power and ground. This DTC will execute regardless of the source voltage.
Conditions for Setting the DTC
This code shall be set when the 2 battery positive voltages differ by 2 volts or greater for more than 10 seconds.
Action Taken When the DTC Sets
All writes to the electrically erasable programmable read only memory (EEPROM) will be suspended. All loss of communication and low/high voltage DTC codes are suspended.
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. |
Reference Information
Schematic Reference
Body Control System Schematics
Connector End View Reference
Computer/Integrating Systems Connector End Views
Electrical Information Reference
Circuit/System Testing
- Ignition OFF, disconnect the C-1 harness connector at the BCM.
- Verify that there is less than a 2 volt difference between the battery positive voltage circuit terminal C1-51 and the ground circuit terminal C1-19, and between the battery positive voltage circuit terminal C1-52 and the ground circuit terminal C1-17.
- If the circuits test normal, replace the BCM.
| ⇒ | If greater than the specified range, test the voltage circuits for a short to ground or open/high resistance, and the ground circuits for open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Refer to Control Module References for module replacement, setup, and programming
