• | 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 X1-51) | B1390 | B1390 | -- | B1390 |
Battery Positive Voltage (BCM X1-52) | B1390 | B1390 | -- | B1390 |
Ground (BCM X1-19) | -- | B1390 | -- | B1390 |
Ground (BCM X1-17) | -- | B1390 | -- | B1390 |
The body control module (BCM) has an internal precision battery voltage sensor connected to dedicated battery positive voltage from X1 terminal 51 and dedicated ground terminal 19. The BCM then compares the sensors voltage to the battery positive voltage from X1 terminal 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
Body Control System Description and Operation
Control Module References for Scan Tool Information
⇒ | 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