Rear IR Sensor Not Calibrated
NOTE:
After making any repairs, perform BODY VERIFICATION TEST under VERIFICATION TESTS.
- Turn ignition switch to OFF position. Disconnect rear zone control panel harness connector. Turn ignition switch to ON position. Using DVOM, measure voltage between ground and rear zone control panel connector terminal No. 1 (Gray/Pink wire). See Figure. If reading is less than 10 volts, go to step 12. If reading is 10 volts or more, go to next step.
- Using DVOM, measure voltage between ground and rear zone control panel connector terminal No. 4 (White/Dark Green wire). See Figure. If reading is less than 10 volts, go to step 10. If reading is 10 volts or more, go to next step.
- Turn ignition switch to OFF position. Disconnect ATC module connector C2. Using DVOM, measure voltage of White/Dark Green wire between ATC module connector C2 terminal No. 10 and rear zone control panel connector terminal No. 4. See Figure and Figure . If reading is less than one volt, go to next step. If reading is one volt or more, repair short to voltage in White/Dark Green wire. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING.
- Turn ignition switch to OFF position. Connect ATC module connector C2. Set up lab scope (oscilloscope) for 12-volt square wave pattern. Set lab scope voltage range to 20 volts with an offset of 4 volts. Set lab scope to 40-millisecond division (40ms/div) scale. Connect lab scope ground lead to chassis ground. Connect lab scope probe lead to rear zone control panel connector terminal No. 3 (White/Tan wire). See Figure. Turn ignition switch to ON position. If lab scope pattern is good and cycles between 0 and 8 volts, go to step 6. If voltage pattern is erratic or does not cycle between about 0 and 8 volts, go to next step.
- Replace rear zone control panel. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING.
- Turn ignition switch to OFF position. Disconnect ATC module connector C2. Turn ignition switch to ON position. Using DVOM, measure voltage in White/Tan wire between ATC module connector C2 terminal No. 9 and rear zone control panel connector terminal No. 3. See Figure and Figure . If reading is less than one volt, go to next step. If reading is one volt or more, repair short to voltage in White/Tan wire. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING.
- Turn ignition switch to OFF position. Measure resistance between ground and ATC module C2 connector terminal No. 9 (White/Tan wire). See Figure. If reading is less than 100 k/ohms, repair short to ground in White/Tan wire between ATC module and rear zone control panel connectors. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING. If reading is 100 k/ohms or more, go to next step.
- Measure resistance between of White/Tan wire between ATC module C2 connector terminal No. 9 and rear zone control panel connector terminal No. 3 (White/Tan wire). See Figure and Figure . If reading is less than 5 ohms, go to next step. If reading is 5 ohms or more, repair open in White/Tan wire between ATC module and rear zone control panel connectors. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING.
- Replace ATC module. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING.
- Turn ignition switch to OFF position. Disconnect ATC module C2 connector. Using DVOM, measure resistance between ground and rear zone control panel connector terminal No. 4 (White/Dark Green wire). If reading is less than 100 k/ohms, repair short to ground in White/Dark Green wire between ATC module and rear zone control panel connectors. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING. If reading is 100 k/ohms or more, go to next step.
- Measure resistance between of White/Dark Green wire between ATC module C2 connector terminal No. 10 and rear zone control panel connector terminal No. 4 (White/Dark Green wire). See Figure and Figure . If reading is less than 5 ohms, go to step 9. If reading is 5 ohms or more, repair short to ground in White/Tan wire between ATC module and rear zone control panel connectors. Calibrate ATC module and actuators. See HVAC CONTROL CALIBRATION under PROGRAMMING.
- Turn ignition switch to OFF position. Connect ATC module C2 connector. Disconnect Body Control Module (BCM) C4 connector. Using scan tool, measure resistance in Gray/Pink wire between rear zone control panel connector terminal No. 1 and BCM connector C4 terminal No. 10. See . If reading is less than 5 ohms, replace BCM. See BODY CONTROL MODULE under REMOVAL & INSTALLATION. If reading is 5 ohms or more, repair open on Gray/Pink wire. Calibrate ATC module and actuators. SeeHVAC CONTROL CALIBRATION under PROGRAMMING.