Inspection Procedure 10

INSPECTION PROCEDURE 10: A/C control panel power supply system.














TECHNICAL DESCRIPTION (COMMENT)

If the voltage is not supplied to the A/C control panel, the power supply or ground system to the control panel may be defective.

TROUBLESHOOTING HINTS

- Malfunction of the A/C control panel
- Damaged wiring harness or connectors

DIAGNOSIS

Required Special Tools:

- MB991223: Harness Set
- MB992006: Extra Fine Probe

STEP 1. Check A/C control panel connector C-216 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is A/C control panel connector C-216 in good condition?

YES Go to Step 2.
NO Repair or replace the connector. Harness Connector Inspection.
STEP 2. Measure the voltage at A/C control panel connector C-216.

(1)Disconnect A/C control panel connector C-216, and measure the voltage at the harness side.

(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal 6 and ground.

- The measured value should be approximately 12 volts (battery positive voltage).

Q. Is the measured voltage approximately 12 volts?

YES Go to Step 4.

NO Go to Step 3.

STEP 3. Check the wiring harness between A/C control panel connector C-216 (terminal 6) and ETACS-ECU connector C-417 (terminal 5).

- Check the A/C control panel power supply line for open circuit.

NOTE:
Also check joint connector C-04 for loose, corroded, or damaged terminals, or terminals pushed back in the connector. If joint connector C-04 is damaged, repair or replace the connector as described in Harness Connector Inspection Harness Connector Inspection.

Q. Is the wiring harness between A/C control panel connector C-216 (terminal 6) and ETACS-ECU connector C-417 (terminal 5) in good condition?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
NO Repair the wiring harness.
STEP 4. Measure the resistance at A/C control panel connector C-216.





(1)Disconnect A/C control panel connector C-216, and measure the resistance at the wiring harness side.
(2)Measure the resistance value between terminal 7 and ground.

- The measured value should be 2 ohms or less.

Q. Does the measured resistance value correspond with this range?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.

NO Go to Step 5.

STEP 5. Check grounding connector C-01 for loose, corroded or damaged terminals, or terminals pushed back in the connector.

Q. Is grounding connector C-01 in good condition?

YES Go to Step 6.
NO Repair or replace the connector. Harness Connector Inspection.
STEP 6. Check the wiring harness between A/C control panel connector C-216 (terminal 7) and grounding connector C-01 (terminal 6).

- Check the A/C control panel ground line for open circuit.

Q. Is the wiring harness between A/C control panel connector C-216 (terminal 7) and grounding connector C-01 (terminal 6) in good condition?

YES It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
NO Repair the wiring harness.