A/C Compressor Lock Sensor Circuit: RAV4
CAUTION:
If Engine Control Module (ECM) replacement is instructed in the following testing, always ensure ECM wiring harness electrical connector and ground circuit are okay. If either are defective, repair and repeat testing to confirm ECM malfunction.
- Remove glove box for access to Engine Control Module (ECM). ECM is located near passenger's side kick panel, just below instrument panel. For illustration of ECM location, see THEORY & OPERATION article. Note terminals on ECM electrical connector. See Figure.
- Turn ignition on. Using voltmeter, check voltage between body ground and terminal No. 15 (Red/Yellow or White wire) at ECM electrical connector E7. This is the ACMG terminal on ECM. There are 2 different wiring harnesses used. Wire color at designated terminal may vary according to wiring harness used. Voltage should be 9-14 volts. If voltage is within specification, go to next step. If voltage is not within specification, check Red/Yellow or White wire and electrical connector between ECM and terminal No. 3 (Red/Yellow or White wire) at electrical connector 3S on passenger's side junction block Electronic Control Unit (ECU). See Fig 1.
- Check A/C compressor drive belt for proper tension. If A/C compressor drive belt has proper belt tension, go to next step. If A/C compressor drive belt does not have proper belt tension, it may be necessary to replace automatic belt tensioner and then go to next step.
- Start engine and note if A/C compressor locks when blower and A/C switches are in ON position. If A/C compressor does not lock, go to next step. If A/C compressor locks, repair A/C compressor as necessary.
- Check A/C compressor lock sensor. See A/C COMPRESSOR LOCK SENSOR under ENGINE SENSORS & SWITCHES. If A/C compressor lock sensor is okay, go to next step. If A/C compressor lock sensor is defective, replace A/C compressor lock sensor.
- Check wiring harness and electrical connectors between A/C compressor lock sensor, passenger's side junction block ECU, A/C amplifier and ECM. See WIRING DIAGRAMS in appropriate article in AIR CONDITIONING & HEATING. A/C amplifier is located behind center of instrument panel. See Fig 1. If wiring harness or electrical connector is defective, repair as necessary. If wiring harness and electrical connectors are okay, check ECM ground circuit. See WIRING DIAGRAMS article. If ECM ground circuit is defective, repair ground circuit as necessary. If ECM ground circuit is okay, replace ECM. On models equipped with engine immobilizer system, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. Models equipped with engine immobilizer system may be identified by looking at the ignition key. On models equipped with engine immobilizer system, the top of the ignition key is thicker than a standard ignition key, as a transponder chip is incorporated into the top of the ignition key. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.