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B1390



DTC B1390

CIRCUIT DESCRIPTION
The body control module (BCM) has an internal battery voltage sensor and a reference voltage. The BCM compares these 2 voltages via the 2 battery positive voltage circuits every 300 milliseconds.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B1390 Device Voltage Reference Input {single or 1} Circuit

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 after 10 consecutive readings that the 2 battery positive voltages differ by one volt or greater.

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.

TEST

Step 1 - Step 7: