HVAC Control Diagnostic Conditions
After calibration, Rear Wiper LED flashing once, Intermittent LED not flashing.The system has passed calibration. Press the Rear Wiper button to exit calibration.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing once. The mode actuator did not reach defrost position.
1. Using a voltmeter, check the mode door actuator wiring connector. Check Pin 1 for battery voltage. Move the HVAC control from the defrost to panel position, and check Pin 6 voltage it should change from 0.5 - 1 volts to 3.5 - 4.5 volts. If voltage is OK, go to Step 2. If not OK, check for loose or corroded connector, open or shorted circuit and repair as necessary.
2. Remove actuator, and check if the gear pins are in the correct track on cam or if they are binding. If OK, go to Step 3. If not OK, repair as necessary.
3. Check for binding door, if door is binding repair as necessary. If gears and door are OK, replace actuator.
4. Once repairs are completed repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing twice. The mode actuator did not reach panel position.
1. Using a voltmeter, check the mode door actuator wiring connector. Check Pin 1 for battery voltage. Move the HVAC control from panel to defrost position, and check Pin 6 voltage it should change from 3.5 - 4.5 volts to 0.5 - 1 volts. If voltage is OK, go to Step 2. If not OK, check for loose or corroded connector, open or shorted circuit and repair as necessary.
2. Remove actuator, and check if the gear pins are in the correct cam track or binding. If OK, go to Step 3. If not OK, repair as necessary.
3. Check for binding door, if door is binding repair as necessary. If gears and door are OK, replace actuator.
4. Once repairs are completed repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing three times. The main temperature actuator/passenger temperature actuator on a zone system did not reach cold stop.
1. Check if the correct HVAC control module was used.
2. Using a voltmeter, check the temperature door actuator wiring connector. Check Pin 1 for battery voltage. Move the HVAC control from the cold to hot position, and check Pin 5 voltage it should change from 0.5 - 4 volts to 3.5 - 4.5 volts. If voltage is OK, go to Step 3. If not OK, check for loose or corroded connector, open or shorted circuit and repair as necessary
3. Remove actuator, and check if gear pins are in the correct cam track or binding. If OK, go to Step 4. If not OK, repair as necessary.
4. Check for binding door, if door is binding repair as necessary If gears and door are OK, replace actuator.
5. Once repairs are completed repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing four times. The main temperature actuator/passenger temperature actuator on a zone system did not reach hot stop.
1. Check if the correct HVAC control module was used.
2. Using a voltmeter, check the temperature door actuator wiring connector. Check Pin 1 for battery voltage. Move the HVAC control from hot to cold position and check Pin 5 voltage it should change from 3.5-4.5 volts 0.5 - 1.5 volts. If voltage is OK, go to Step 3. If not OK, check for loose or corroded connector, open or shorted circuit and repair as necessary
3. Remove actuator, and check if the gear pins are in the correct track on cain or if they are binding. If OK, go to Step 4. If not OK, repair as necessary
4. Check for binding door, if door is binding repair as necessary If gears and door are OK, replace actuator.
5. Once repairs are completed repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing five times. The evaporator probe is open.
1. Using a voltmeter, check Pin 1 of the evaporator probe wiring connector for 0.1 - 4.75 volts. If OK, go to Step 2. If not OK, if greater than 4.75 volts check for loose or corroded connector, open circuit and repair as necessary
2. Using a ohmmeter, check Pin 2 for a good ground, If OK, go to Step 3. If not OK, check for loose or corroded connector, open or shorted circuit and repair as necessary
3. If ground and power circuit are OK, replace Evaporator Probe.
4. Once repairs are completed, press the intermittent button about 5 seconds until all LED's light to remove fault code from memory Then repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing six times. The evaporator probe is shorted.
1. Using a voltmeter, check Pin 1 of the evaporator probe wiring connector for 0.1 - 4.75 volts. If OK, go to Step 2. If less than 0.1 volts, check for loose or corroded connector, open or shorted circuit and repair as necessary.
2. Using a ohmmeter, check Pin 2 for a good ground, If OK, go to Step 3. If not OK, check for shorted circuit and repair as necessary.
3. If ground and power circuit are OK, replace Evaporator Probe
4. Once repairs are completed, press the intermittent button about 5 seconds until all LED's light to remove fault code from memory. Then repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing seven times. The Driver's temperature actuator on a zone system did not reach cold stop.
1. Check if the correct HVAC control module was used.
2. Using a voltmeter, check at the temperature door actuator wiring connector, check Pin 1 for battery voltage. Move the HVAC control from cold to the hot position, check Pin 4 voltage it should change from 0.5 - 1.5 volts 3.5 - 4.5 volts. If voltage is OK, go to Step 3. If not OK, check for loose or corroded connector, open or shorted circuit and repair as necessary
3. Remove actuator, and check if the gear pins are in the correct track on cam or if they are binding. If OK, go to Step 4. If not OK, repair as necessary.
4. Check for binding doors, if door are binding repair as necessary. If gears and door are OK, replace actuator.
5. Once repairs are completed repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing eight times. The Driver's temperature actuator on a zone system did not reach hot stop.
1. Check if the correct HVAC control module was used.
2. Using a voltmeter, check at the temperature door actuator wiring connector, check Pin 1 for battery voltage. Move the HVAC control from hot to cold position, Pin 4 voltage it should change from 3.5 - 4.5 volts to 0.5 - 1.5 volts. If voltage is OK, go to Step 3. If not OK, check for loose or corroded connector, open or shorted circuit and repair as necessary.
3. Remove actuator, and check if the gear pins are in the correct track on cam or if they are binding. If OK, go to Step 4. If not OK, repair as necessary
4. Check for binding door, if door is binding repair as necessary. If gears and door are OK, replace actuator.
5. Once repairs are completed repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration, Rear Wiper LED flashing once, Intermittent LED flashing nine times. The HVAC control module, has a internal failure.
1. Replace the HVAC control module.
2. Once repairs are completed repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.
After calibration and testing the NC and RECIRC LED flashing simultaneously. Failed Cool-down test.
1. Determine if the refrigerant system is operating correctly:
- Check the outlet air temperature
- Feel the compressor suction plumbing, is it hot?
2. If not OK, go to Step 3. If OK, repeat the Calibration Diagnostic and Cool-down test.
3. If system does not seem to be operating correctly, perform diagnostics for poor performance:
- Low refrigerant charge
- No charge
- Compressor not operating
Verify that the test was done with the evaporator at room temperature. The test consists of starting the compressor and measuring the time it takes for the evaporator temperature to fall 7 degree Celsius (20 degree Fahrenheit). If the compressor has been running, the evaporator is cold already and will not be capable of falling 7 degree Celsius (20 degree Fahrenheit). If the test was run with a cold evaporator, turn A/C off and turn the blower motor switch to high position for 3 to 5 minutes till the evaporator is to room temperature. Then repeat the Calibration Diagnostic and Cool-down test.
If refrigerant system is performing properly and the system will not pass test. Repeat the Calibration Diagnostic and Cool-down test to determine if the evaporator temperature FIN sensor has developed an open or a short circuit. If the HVAC control module still passes Calibration test, verify Cool-down test manually with a pocket thermometer. The outlet air temperature must drop at least 7 degree Celsius (20 degree Fahrenheit) within two minutes. If the vehicle passes with the manual thermometer, take HVAC control to level 4 (evaporator probe temperature readout) and repeat the Cool-down test. Ensure the evaporator is at room temperature before starting test. Check if evaporator probe will drop the temperature 7 degree Celsius (20 degree Fahrenheit) in two minutes. If the Evaporator Probe is found to be faulty, check that the sensor is positioned in the evaporator fins properly. If not, correct and repeat test. If OK, replace the evaporator probe.
Once the repairs are completed, repeat the Calibration Diagnostic and Cool-down test. Repeating the test is necessary to clear the fault codes.