For 1990-2009 cars

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 |

1. Turn ON the ignition, with the engine OFF.
2. Set the blower speed manually for 5th speed.
3. Measure the voltage between the ATC controller terminal A10 and ground.

Is the voltage approximately equal to the specified value?

0 ohms

Go to Step 3

Go to Step 2

2 | Replace the ATC controller. Refer to Heater and Air Conditioning Control Replacement . Is the repair complete? | -- | System OK | --
3 |

1. Inspect the wiring harness associated with the MAX-HI relay for defects or high terminal resistance.
2. Repair any defects found.

Is the repair complete?

--

System OK

Go to Step 4

4 | Replace the MAX-HI relay. Refer to Blower Motor Relay Replacement . Is the repair complete? | -- | System OK | --