Test F: DTC B1263 Or DTC B1264 - Panel/Defrost Or Floor Door Failure

PINPOINT TEST F: DTC B1263 OR DTC B1264 - PANEL/DEFROST OR FLOOR DOOR FAILURE

F1-F2:

F3-F4:

F5-F7:

F7-F9:

F9-F10:

F10 Continued:

F10-F11:

F11 Continued:

F12-F13:

F13-F14:

F14-F15:

F15-F16:

Normal Operation
Under normal operation, the panel/defrost and floor door actuator motors are supplied voltage or ground on circuit 1380 (TN/YE) (panel/defrost) or circuit 1376 (BK/LB) (floor), depending on desired actuator rotation, by the electronic automatic temperature control (EATC) module. The EATC module then supplies the appropriate voltage or ground to the other side of the actuator motor on circuit 1379 (PK/LB) (panel/defrost) or circuit 1375 (PK/YE) (floor).

The panel/defrost and floor door actuator feedback resistors are supplied a ground from the EATC module by circuit 438 (RD/WH) and a 5 volt reference voltage on circuit 436 (RD/LG). The EATC module reads the voltage on circuit 1123 (YE/WH) (panel/defrost) or circuit 1130 (PK/LG) (floor) 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 436 (RD/LG), 438 (RD/WH), 1123 (YE/WH), 1130 (PK/LG),1375 (PK/YE), 1376 (BK/LB), 1379 (PK/LB) or 1380 (TN/YE)
- Panel/defrost or floor door actuator
- Electronic automatic temperature control (EATC) module
- Stuck or bound linkage or door