For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 |

1. Remove the heater and A/C control unit.
2. Disconnect connector C1 from the heater and A/C control unit.
3. Disconnect the connector from the blower control module.
4. Test CKT XM112 (BRN/WHT) for a short to voltage. (Turn ON the ignition, leaving the engine OFF, when testing for a short to voltage.)

Did you find a short to voltage on CKT XM112?

--

Go to Step 2

Go to Step 3

2 | Repair the short to voltage on CKT XM112 (BRN/WHT). Did you complete the repair? | -- | Go to Step 4 | --
3 | Replace the blower control module. Did you complete the replacement? | -- | Go to Step 4 | --
4 |

1. Reassemble any connectors/components removed in previous steps.
2. Turn the ignition switch to the ON position.
3. Select AUTO mode on the heater & A/C control.
4. Cycle through all the blower speeds.

Do all the blower speeds operate properly?

--

System OK

Go to Step 5

5 | Replace the heater & A/C control unit. Did you complete the replacement? | -- | Go to Step 6 | --
6 | Operate the system for which the symptom occurred. Is the symptom still present? | -- | -- | System OK