For 1990-2009 cars

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Measure the voltage between terminal 4 and ground of the mode motor and the HTR/DEF motor. Is the voltage within the specified value for both motors? | 11-14 V | Go to Step 3 | Go to Step 2
2 |

1. Inspect the connector and circuit for any wiring or terminal problems.
2. Repair any problems found.

Is the repair complete?

--

System OK

--

3 |

1. To measure the voltages at the specified terminals of the specified motor connectors, refer to Motor Control Table .
2. Change the mode settings and observe the voltage changes.

Are the voltages within the Motor Control table?

--

Go to Step 4

Go to Step 5

4 | Replace the motor that does not operate properly. Is the repair complete? | -- | System OK | --
5 |

1. To measure the voltages at the specified terminals of the specified controller connectors, refer to Motor Control Table .
2. Change the mode settings and observe the voltage changes.

Are the voltages within the Motor Control table?

--

Go to Step 6

Go to Step 7

6 |

1. Inspect the wiring harness and connectors between the controller and the motor that is not performing properly.
2. Repair or replace the wiring harness or the defective terminal.

Is the repair complete?

--

System OK

--

7 | Inspect the connector at the controller. Is there a defective terminal? | -- | Go to Step 8 | Go to Step 9
8 | Repair or replace the terminal. Is the repair complete? | -- | System OK | --
9 | Replace the controller. Refer to Heater and Air Conditioning Control Replacement . Is the repair complete? | -- | System OK | --