• | 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. |
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 |
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.
This DTC will run only if the BCM has power and ground. This DTC will execute regardless of the source voltage.
This code shall be set when the 2 battery positive voltages differ by 2 volts or greater for more than 10 seconds.
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.
• | 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. |
Body Control System Schematics
Computer/Integrating Systems Connector End Views
⇒ | 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. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Refer to Control Module References for module replacement, setup, and programming