HVAC SYSTEM (AUTO A/C) (DIAGNOSTICS) > Diagnostic Procedure for Actuators

PTC HEATER

DIESEL ENGINE MODEL

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK PTC HEATER.

Perform the self-diagnosis of A/C.

Is the PTC heater operation normal?

Finish the diagnosis.

2.CHECK PTC HEATER RELAY.

1) Turn the ignition switch to OFF.

2) Remove the PTC heater relay.

3) Check the PTC heater relay.

Is the PTC heater relay normal?

Replace the PTC heater relay.

3.CHECK HARNESS.

Use a tester to measure the voltage between the relay holder and chassis ground.

Connector & terminal

(F9) No. 7 (+) — Chassis ground (−):

(F9) No. 5 (+) — Chassis ground (−):

(B473) No. 1 (+) — Chassis ground (−):

(B473) No. 2 (+) — Chassis ground (−):

(B473) No. 6 (+) — Chassis ground (−):

(B473) No. 7 (+) — Chassis ground (−):

(B473) No. 11 (+) — Chassis ground (−):

(B473) No. 12 (+) — Chassis ground (−):

Is the voltage battery voltage?

Check the DC power supply circuit.

4.CHECK HARNESS.

1) Turn the ignition switch to OFF.

2) Disconnect the auto A/C control module connector.

3) Measure the resistance between auto A/C control module connector and relay holder.

Connector & terminal

(i88) No. 12 — (F9) No. 8:

(i88) No. 33 — (F9) No. 8:

(i88) No. 29 — (B473) No. 4:

(i88) No. 30 — (B473) No. 9:

(i88) No. 5 — (B473) No. 14:

Is the resistance less than 10 Ω?

Repair or replace the harness.

5.CHECK HARNESS.

1) Turn the ignition switch to OFF.

2) Use a tester to measure the resistance between the relay holder and chassis ground.

Connector & terminal

(F9) No. 6 — Chassis ground:

(B473) No. 5 — Chassis ground:

(B473) No. 10 — Chassis ground:

(B473) No. 15 — Chassis ground:

Is the resistance less than 10 Ω?

Repair or replace the harness.

6.CHECK HARNESS.

1) Turn the ignition switch to OFF.

2) Disconnect the PTC heater connector.

3) Use a tester to measure the resistance between the relay holder and PTC heater.

(F9) No. 6 — (B461) No. 2:

(F9) No. 6 — (B462) No. 2:

(B473) No. 5 — (B470) No. 2:

(B473) No. 10 — (B471) No. 1:

(B473) No. 15 — (B471) No. 3:

Is the resistance less than 10 Ω?

Repair or replace the harness.

7.CHECK HARNESS.

1) Turn the ignition switch to OFF.

2) Use a tester to measure the resistance between the PTC heater and chassis ground.

Connector & terminal

(B461) No. 1 — Chassis ground:

(B462) No. 1 — Chassis ground:

(B470) No. 1 — Chassis ground:

(B471) No. 2 — Chassis ground:

Is the resistance less than 10 Ω?

Repair or replace the harness.

8.CHECK CONTROL MODULE.

1) Turn the ignition switch to OFF.

2) Connect the disconnected connectors.

3) Disconnect the auto A/C control module connector.

4) Short the harness connector to chassis ground.

Connector & terminal

(i88) No. 33 — Chassis ground:

(i88) No. 12 — Chassis ground:

(i88) No. 29 — Chassis ground:

(i88) No. 30 — Chassis ground:

(i88) No. 5 — Chassis ground:

Does PTC heater become warm?

Replace the auto A/C control module.

Replace the PTC heater.