Reading and Clearing Diagnostic Trouble Codes
Self-Test Procedures1. Turn ignition off, then back on to reset the system.
2. Ensure engine coolant temperature is at least 120°F.
3. Set control head to Auto/90°F. Wait a minimum of 40 seconds, then verify the following conditions:
a. System goes to high blower and warm air is being discharged from floor.
b. Recirc door is in "outside air" position.
c. Warm air is bleeding out of defroster nozzle.
4. Enter "self-test", then record all faults and error codes displayed. Exit "self-test" and diagnose error code(s).
5. Set control head to Auto/60°F. Wait a minimum of 40 seconds, then verify the following conditions:
a. Cool air is being discharged from panel.
6Gb. Recirc door is in "recirc" position.
6. Enter "self-test", then record all faults and error codes displayed. Exit "self- test" and diagnose error code(s).
7. Repeat steps 3 and 4.
8. Perform pinpoint tests H through P, if any other faults still exist.
When diagnosing a vehicle at idle, the system will likely discharge cool air from the panel up to an "85°" set point due to engine heat acting on the ambient sensor. Because of this, the vehicle should be road tested as a final checkout.
1. Perform EATC Functional Test. Record all error codes displayed during test.
2. If error codes appear during EATC Functional Test, follow diagnosis procedures outlined in Error Code Key for each error code recorded.
3. If a malfunction exists but no error code appears during the test in Step 1, refer to Diagnosis when Self Test indicates No Error Found.
How to Use the System Problem Indication/Self-Test Feature
-The control assembly will detect electrical malfunctions occurring during the self test.
-Ensure that the engine is warm (at least 49°C (120°F) coolant temperature). To display the error codes for the malfunction detected, initiate the self test by pushing OFF and FLOOR simultaneously and then AUTO within two seconds. The test may run as long as 20 seconds, during which time the display will be blank. If the display is blank for more than 20 seconds, go to System Diagnosis When Self Test and Functional Test Indicate NO ERROR.
-The self test can be initiated at any time with the resulting error codes being displayed. Normal operation of the system stops when Self Test is activated. To exit the self test and restart the system, push the COOLER button. The self test should be deactivated before powering the system down. Refer to the Error Code Key for an explanation of error codes.
DIAGNOSIS WHEN SELF-TEST INDICATES NO ERRORS FOUND
