BCM Code B337, Loss Of A/C-Heater Programmer Data: Notes

Code B337 will set if ignition is on and BCM has lost data communication with A/C-heater programmer. Fault can be caused by a loss of 12-volt power, ground to programmer or a double open in programmer data line, one on each side of component. During a failure, A/C clutch is disabled and blower motor runs at a constant 6 volts.

1. Ensure code is not intermittent.
2. Determines if fault is due to power or ground circuits or data line.
3. Determines if data line fault is due to wiring or programmer.
4. Checks IGN 3 to programmer.
5. Determines if loss of ground is due to programmer, wiring or CPS.