| • | 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  | 
|---|---|---|---|---|
5-Volt Reference  | B1405 00, B1516 08  | B1516 08  | B1405 00  | --  | 
Signal  | B1516 08  | B1516 08  | B1516 08  | B1516 08, B1516 66  | 
Low Reference  | --  | B1516 08  | --  | --  | 
Circuit  | Short to Ground  | Open  | Short to Voltage  | 
|---|---|---|---|
Operating Conditions: Ignition ON, engine OFF. Headlamps and all accessories OFF. Parameter Normal Range: -5 amps to -10 amps  | |||
5-Volt Reference  | -59.9 amps  | -59.9 amps  | --  | 
Signal  | -59.9 amps  | 59.9 amps  | 59.9 amps  | 
Low Reference  | --  | 59.9 amps  | --  | 
The battery current sensor is a 3-wire hall effect current sensor. The battery current sensor monitors the current through the negative battery cable. It directly inputs to the body control module (BCM). It creates a 5-volt pulse width modulation (PWM) signal of 128 Hz, and varies the duty cycle. The BCM supplies a 5-volt reference to the battery current sensor. If the BCM detects that the 5-volt reference circuit is shorted, then DTC B1405 sets.
The BCM is awake.
The BCM detects that the 5-volt reference circuit is shorted to ground or shorted to voltage.
The regulated voltage control (RVC) is disabled.
The DTC passes when the voltage on the 5-volt reference circuit returns to the normal range for 5 seconds.
Starting and Charging Schematics
Charging System Description and Operation
Control Module References for scan tool information
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. | 
| ⇒ | If less than the specified range , test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, then replace the BCM. | 
| ⇒ | If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, then replace the BCM. | 
| ⇒ | If less than the specified range, test the signal circuit terminal C for a short to ground. If the circuit tests normal, replace the BCM. | 
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming. |