For 1990-2009 cars

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

1. Turn the ignition to ON.
2. Observe the temperature indication screen of the controller.

Does the digit go on and off?

--

Go to Step 2

Go to Step 3

2 | Run a self-diagnosis circuit check. Does the display indicate a defect code? | -- | Go to the table for the code that flashes. | --
3 | Check fuse F18 in the I/P fuse block. Is this fuse in good condition? | -- | Go to Step 5 | Go to Step 4
4 | Replace fuse F18. Is the repair complete? | -- | System OK | --
5 |

1. Turn the ignition switch to ON.
2. Measure the voltage between ground and terminal 85 of the blower relay.

Is the voltage within the specified value?

11-14 V

Go to Step 15

Go to Step 8

6 | Measure the voltage between ground and terminal 30 (BN/WH) at the blower relay. Is the voltage within the specified value? | 11-14 V | Go to Step 8 | Go to Step 7
7 | Repair any problem found in terminal 85 at the relay connector, or ground G203. Is the repair complete? | -- | System OK | --
8 | Replace the blower relay. Is the repair complete? | -- | System OK | --
9 |

1. Turn the ignition switch to OFF.
2. Disconnect the wiring harness at the blower motor.
3. Turn the ignition switch to ON.
4. Measure voltage between ground and blower connector 2.

Is the voltage within the specified value?

11-14 V

Go to Step 11

Go to Step 10

10 |

1. Turn the ignition switch to OFF.
2. Check circuit YE between blower connector terminal 2 and blower relay terminal 30.
3. Repair any problem found in the wiring or a connector terminal at the blower connector, connector J209, or the blower relay socket.

Is the repair complete?

--

System OK

--

11 | Measure the resistance between the connector terminals on the blower motor. Does the resistance match the specified value? | 5 ohms | Go to Step 13 | Go to Step 12
12 | Replace the blower motor. Is the repair complete? | -- | System OK | --
13 | Measure the resistance of circuit between terminal 1 of the blower connector and terminal 30 of the Max HI relay and terminal 2 of the power module. Does the resistance match the specified value? | 0 ohms | Go to Step 15 | Go to Step 14
14 | Repair the problem in circuit. Is the repair complete? | -- | System OK | --
15 | Measure the resistance of circuit from terminal 4 of the power module connector to ground. Does the resistance match the specified value? | 0 ohms | Go to Step 17 | Go to Step 16
16 |

1. Trace circuit from terminal 4 of the power module connector and terminal 87 of the Max HI relay to ground G203.
2. Repair any problem found in the wiring, ground G203.

Is the repair complete?

--

System OK

--

17 | Replace the ATC controller. Is the repair complete? | -- | System OK | --