QuestionQUESTION: The heat in my 2002 Voyager won't work unless I'm accelerating. When I come to a stop it gets cold. Fan works fine. I've already replaced the thermostat, added coolant. I think it could be the air/blend door perhaps, if so where is this located? Any other suggestions you have would be appreciated. Merry Christmas!!
ANSWER: Hi Georges,
You may well be correct about the blend air door, but not that it is broken but rather that it out of adjustment. Fortunately there is a self-calibration of the doors, and self-diagnostic routine that you can perform using the buttons on the control panel. Here is the summary from the shop manual:
"DIAGNOSTICS
During the Actuator calibration, diagnostics are performed on the actuators and evaporator temperature Fin Sensor. Once diagnostics are completed the REAR WIPER and INTERMITTENT LED's will flash to indicate either a successful calibration or the appropriate fail code(s) At this time manual testing of the Blend, Mode and Driver (if equipped) potentiometers can be performed. If a failure is detected during Diagnostics a fault will be set in the control. When Ignition is cycled OFF and then ON or Diagnostics is aborted, the REAR WIPER and INTERMITTENT LED's will flash simultaneously showing that a failure has occurred. The control will not indicate the fail code, but only that a failure had occurred during the last diagnostics test. The only way to clear the failure codes is repeat the Calibration Diagnostic and Cooldown test, after all repairs are completed. The engine must be running for these diagnostic/calibrations to be performed.
COOLDOWN TEST
This test has been designed for performance testing of the A/C system at the manufacturing facility. If the HVAC control module is replaced, the Cooldown test will occur during Calibration test. Cooldown will not occur on Heater Only units. During the Cooldown test the control will monitor the temperature of the Fin Sensor. The A/C system must be able to bring the evaporator temperature down a predetermined minimum amount in less than 2 minutes.
CALIBRATION/COOLDOWN LED DISPLAY CODES
See table for definition of flashing LED's. If no problems are found, the control functions normally.
CALIBRATION/COOLDOWN LED DISPLAY CODES
LED'S PASS/FAIL CORRECTIVE ACTION
NO LED'S FLASHING-NORMAL OPERATION PASSED CALIBRATION, DIAGNOSTICS AND COOLDOWN NONE
REAR WIPER AND INTERMITTENT LED'S FLASH SIMULTANEOUSLY FAILED CALIBRATION DIAGNOSTICS RUN CALIBRATION TEST
A/C AND RECIRC LED'S FLASH SIMULTANEOUSLY FAILED COOLDOWN RUN COOLDOWN TEST
REAR WIPER AND INTERMITTENT LED'S ARE FLASHING SIMULTANEOUSLY A/C AND RECIRC LED'S ARE FLASHING SIMULTANEOUSLY FAILED CALIBRATION, DIAGNOSTICS AND FAILED COOLDOWN TEST RUN CALIBRATION TEST
CALIBRATION/DIAGNOSTICS TEST ENTRY
TO INITIATE TESTS:
Set Blower motor ON HIGH
Set Mode position to Panel
Open all A/C outlets
Set Temperature to Cold (Both slide pots if equipped)
Depress WASH and REAR WIPER button simultaneously for 5 Seconds (Until all LED's light)
RESULTS:
All LED's will turn on for 5 Seconds
Calibration Test is running when REAR WIPER and INTERMITTENT are alternately flashing. Cooldown test is running if A/C and RECIRC are alternately flashing.
Acceptable results is REAR WIPER LED is the only LED flashing. Push Rear Wiper to exit.
After all tests have passed, Calibration Diagnostics and Cooldown can be run separately.
COOLDOWN TEST ENTRY
TO INITIATE TESTS:
Set Blower motor ON HIGH
Set Mode position to Panel
Open all A/C outlets
Set Temperature to Cold (Both slide pots if equipped)
Depress WASH and A/C simultaneously for 5 Seconds
NOTE: Prior to start of test, If the evaporator is already cold, the system will fail test. To correct, operate system with A/C OFF and the blower motor ON high for three minutes prior to starting test.
RESULTS:
All LED's will turn on for 5 Seconds
Cooldown Test is running when A/C and RECIRC. are alternately flashing. If A/C and RECIRC. are flashing simultaneously, Cooldown has failed.
CALIBRATION DIAGNOSTICS AND COOLDOWN ABORT
Test can be aborted by doing one of the following:
Depressing Rear Window Defogger, RECIRC and Rear Wiper buttons.
Cycling Ignition OFF and then ON.
Control will automatically abort after 15 minutes from the time Calibration Diagnostics and Cooldown was entered.
The HVAC control module will return to normal operation or may indicate unsuccessful Calibration Diagnostics or Cooldown test by LED's flashing simultaneously"
While this may sound complex, just begin the process at "CALIBRATION/DIAGNOSTICS TEST ENTRY"
and watch to see what happens. You are not particularly interested in the cooldown part now as that related to the AC function. Often just running the calibration will solve the problem. Let me know please how it works out. The blend door is operated by an electrical actuator, and it is located on the left side of the housing. But let's not deal with that until you try the Calibration/Diagnostics.
Roland
PS Use the 'thank/rate' tab below to get back to me with the results, without having to wait for me to be available to take a question. While you are there please notice the question about a 'nomination for expert of the month' for me. If you would be so kind as to enter a 'yes' I would appreciate that greatly as I am in a 'tight' race for December. Thanks in advance.
Response
I tried the procedure as outlined. I could not get the calibration to function correctly. I referred to the manual to make sure I was making the right selections but the test still did not work. Is the car supposed to be running? I tried both motor runnning and not running, ignition on and not on, still didn't work.
Hi Georges,
Yes, the motor must be running, and I would believe you should have it warmed up. Sorry, that wasn't in the original but I added that point above. If the test still doesn't "go" then I would wonder about an issue or fault in the control panel. But do try it again, being sure to hold down the buttons simultaneously and for long enough to get the LED's to flashing. Thanks for the nomination.
Roland
---------- FOLLOW-UP ----------
QUESTION: Roland,
I have tried the procedure several times and get no response. Maybe it's different because it's a 2002. Is there anything else I can try? Is there a different procedure for the 2002 models? Thanks for your help!
AnswerHi Georges:
How did the retest go?
I would really appreciate one more 'nomination' if you get this in time. The voting ends at 6 pm CST today (New Year's Eve),
Happy New Year!
Roland
Hi Georges,
I checked the previous answered question for Kevin, my colleague here at Allexperts, and found that there is a different way to start the tests (in this case the cooldown which tests the AC part) and so give one or the other of these a test and see what happens. If it seems to respond, then what I would do is note the result and ask Kevin what is the test for the 'calibration' part of the self-test for an '02 model and he should be able to tell you that. I am sorry to not have access to an '02 manual as none has come up for sale at a price that I can afford as a volunteer expert.
Roland
PS Thanks for the previous 'nominations' and feel free to do it again!
MANUAL TEMPERATURE CONTROL
The front blower speed and rear blower speed (if equipped with rear HVAC) must be set to High and the evaporator temperature sensor must be greater than 55° F or the test will fail immediately. The test is activated by depressing the A/C and PWR buttons simultaneously and holding them depressed for no less than five seconds. The PWR and A/C LEDs will blink on and off until the test is complete. If the LEDs stop blinking before two minutes, then the cool down test has been completed successfully. If the two minutes expire without the expansion valve temperature reaching 20° F less than the outside air temperature, then the cool down test has been failed and further A/C system diagnosis is required. If the test is failed, the LEDs will continue to blink until the vehicle has been driven for greater than (8 miles).
AUTOMATIC TEMPERATURE CONTROL
The ambient air temperature in the room where the vehicle will be tested must be a minimum of 21° C (70°F) for this test. The test is activated by depressing the A/C and PWR buttons simultaneously and holding them depressed for no less than four seconds. The snowflake icon and the DELAY text in the ATC display will blink on and off alternately until the test is complete. If the snowflake icon and the DELAY text stop blinking before two minutes, then the cool down test has been completed successfully. If the two minutes expire without the evaporator temperature reaching 20° F less than the evaporator initial temperature, then the cool down test has been failed and further A/C system diagnosis is required. If the test is failed, the snowflake icon and the DELAY text will continue to blink across ignition cycles until the vehicle has been driven for greater than (8 miles).
