Test A: DTC B1249 - Blend Door Failure or Short

PINPOINT TEST A: DTC B1249 - BLEND DOOR FAILURE OR SHORT

A1:

A1-A3:

A3-A5:

A5-A7:

A7-A9:

A9-A11:

A11-A13:

A14-A16:

A17-A18:

Normal Operation
Under normal operation, the temperature blend door actuator motor is supplied voltage or ground on circuit 249 (DB/LG), depending on desired actuator rotation, by the remote climate control (RCC) module. The RCC module then supplies the appropriate voltage or ground to the other side of the actuator motor on circuit 250 (OG).

The temperature blend door actuator feedback resistor is supplied a ground from the RCC module by circuit 438 (RD/WH) and a 5-volt reference voltage on circuit 436 (RD/LG). The RCC module reads the voltage on circuit 437 (YE/LG) to determine the actuator position by the position of the actuator feedback resistor wiper arm.

Possible Causes
- An open, short to voltage, ground or together in circuits 249 (DB/LG), 250 (OG), 436 (RD/LG), 437 (YE/LG) or 438 (RD/WH)
- Temperature blend door actuator
- Remote climate control (RCC) module
- Stuck or bound linkage or door