Inspection Procedure 7: A/C control unit power supply system










PROBABLE CAUSES



  • Malfunction of compressor & heater controller
  • Damaged harness wires and connectors

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-101 A/C control unit connector

Q. Is the check result normal?
Go to Step 2.
Repair the damaged connector.

STEP 2. Measure the voltage at C-101 A/C control unit connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Voltage between terminal No. 13 and body earth
OK: Battery voltage

Q. Is the check result normal?
Go to Step 4.
Go to Step 3.

STEP 3. Check the wiring harness between C-101 A/C control unit connector terminal No. 13 and the fusible link (25).

  • Check the power supply line for open circuit.
note Before checking the wiring harness, check the junction block connectors B-301, joint connectors B-05, and B-06, and repair them if necessary.

Q. Is the check result normal?
Intermittent malfunction. Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, - How to Cope with Intermittent Malfunctions .)
Repair the wiring harness.

STEP 4. Measure the voltage at B-101 A/C control unit connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Voltage between terminal No. 15 and body earth
OK: Battery voltage

Q. Is the check result normal?
Go to Step 6.
Go to Step 5.

STEP 5. Check the wiring harness between C-101 A/C control unit connector terminal No. 15 and B-309 A/C relay connector terminal No. 3.

  • Check the power supply line for open circuit.
note Before checking the wiring harness, check the junction block connectors B-302 and B-301, and repair them if necessary.

Q. Is the check result normal?
Intermittent malfunction. Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, - How to Cope with Intermittent Malfunctions .)
Repair the wiring harness.

STEP 6. Measure the resistance at C-101 A/C control unit connector.
(1)Disconnect the connector, and measure at the wiring harness side.
(2)Resistance between terminal No. 14 and body earth
OK: Continuity exists (2 Ω or less)

Q. Is the check result normal?
Replace the compressor & heater controller.
Go to Step 7 <LHD>.
Go to Step 8 <RHD>.

STEP 7. Check the wiring harness between B-315 A/C control unit connector terminal No. 14 and earth connector terminal No. 1.

  • Check the earth wires for open circuit.

Q. Is the check result normal?
Intermittent malfunction. Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, - How to Cope with Intermittent Malfunctions .)
Repair the wiring harness.

STEP 8. Check the wiring harness between B-315 A/C control unit connector terminal No. 14 and the body earth.

  • Check the earth wires for open circuit.

Q. Is the check result normal?
Intermittent malfunction. Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points, - How to Cope with Intermittent Malfunctions .)
Repair the wiring harness.