• | 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 |
---|---|---|---|---|
Generator Field Duty Cycle Signal | B1492 | B1492 | -- | -- |
Circuit | Short to Ground | Open | Short to Voltage |
---|---|---|---|
Operating Conditions: Engine running. Parameter Normal Range: 5 - 99% | |||
Generator Field Duty Cycle Signal | 0% | 0% | 99% |
The generator battery control module (GBCM) monitors the generator through the generator field duty cycle signal circuit. The signal is a pulse width modulation (PWM) signal of 128 Hz with a duty cycle of 0-100 percent. Normal duty cycle is between 5-95 percent. If the generator field duty cycle signal circuit is in the 0-5 percent range or pulled low to ground, then DTC B1492 will set.
The engine is running.
The generator field duty cycle signal circuit is less than 5 percent duty cycle for 2 minutes.
• | The charge indicator turns ON. |
• | The driver information center (DIC) displays the BATTERY NOT CHARGING message. |
• | The DTC will pass when the generator field duty cycle signal circuit has greater than 5 percent duty cycle. |
• | The charge indicator and DIC message will remain ON until the ignition is cycled after the DTC clears. |
Starting and Charging Schematics
Charging System Description and Operation
Control Module References for scan tool information
Engine running, observe the scan tool ECM GEN-F Terminal Signal parameter. The parameter should read between 5 and 95 percent.
⇒ | If the parameter was not affected by the test lamp, test the circuit for a short to voltage, short to ground, or an open/high resistance. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for GBCM replacement, setup, and programming. |