Code B410: Charging System Circuit: Notes

The generator on this vehicle has fault detection capability built into the regulator. The BCM will supply 12-volts to the regulator over CKT 225, the I-terminal, and monitor the field voltage of the generator by way of a PWM signal over CKT 23, the F-terminal. Code B410 will be set if there is an open or short to ground in either CKT 23, 225 or 725, or a drive belt break. If there is a short to ground on CKT 225 or 725, the NO CHARGE telltale will light on the IPC. The following is in reference to steps listed in flow chart:

1. BCM input BI51 displays generator signal voltage as HI or LO, depending on the voltage state at the BCM. Normally with key on, engine off, CKT 225 will be pulled LO by the generator and BI51 will read LO.
2. This step checks to see if the LO reading is due to CKT 225 or 725, or the generator. If the reading changes from LO to HI when the generator is disconnected, then CKT 225 and BCM are okay.
3. This step determines if the fault is due to the BCM or CKT 225.
4. BCM data value BD51 displays the amount of generator field activity. Under normal conditions, a reading below 5% would indicate a fault in the field circuit or BCM.
5. Removing the generator connector will determine if the fault is due to the generator or an open in CKT 225, including the BCM and interface connector.

For flow chart and circuit diagnosis, refer to illustrations. See Figure and Fig 1 .