Camry Solara With Manual A/C & MR2
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.
- 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.
- On Camry Solar, remove glove box for access to Engine Control Module (ECM). For illustration of ECM location, see THEORY & OPERATION article. On MR2, remove luggage compartment lids, luggage compartment boxes and quarter trim panels for access to Engine Control Module (ECM). ECM is located on inside of firewall, directly behind driver's seat and luggage compartment. For illustration of ECM location, see THEORY & OPERATION article. For additional information on removal of luggage compartment components, see FUEL PUMP under FUEL SYSTEMS in REMOVAL, OVERHAUL & INSTALLATION - 4-CYLINDER article.
- On all models, note ECM electrical connector terminals. See Figure and Figure
. Connect oscilloscope between proper terminals on ECM for A/C compressor lock sensor. See ECM TERMINAL IDENTIFICATION & CIRCUIT IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR table. These are the LCK1 and E1 terminals at ECM.ECM TERMINAL IDENTIFICATION & CIRCUIT IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR
Application ECM Connector ECM Terminal No. (Wire Color) Camry Solara E9 (1) 23 (White/Blue) E9 (2) 1 (Brown) MR2 E3 (1) 28 (White/Red) E4 (2) 17 (Brown) (1) This is the A/C compressor lock sensor signal circuit at ECM. (2) This is the ground circuit at ECM. - Check A/C compressor lock sensor wave pattern on oscilloscope during cranking or with engine idling. A/C compressor lock sensor wave pattern should switch from between zero volts and .2 volts within 20 milliseconds. See Fig 1. If A/C compressor lock sensor wave pattern is as specified, go to next step. If A/C compressor lock sensor wave pattern is not at specified, replace A/C compressor lock sensor.
- On Camry Solara, go to next step. On MR2, check A/C compressor clutch relay. See A/C COMPRESSOR CLUTCH RELAY under MODULES, MOTORS, RELAYS & SOLENOIDS. If A/C compressor clutch relay is okay, go to next step. If A/C compressor clutch relay is defective, replace A/C compressor clutch relay.
- On all models, check wiring harness and electrical connectors for A/C compressor lock sensor between ECM and A/C compressor lock sensor for any problems. See ECM TERMINAL IDENTIFICATION & CIRCUIT IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR table. 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. If ECM is replaced and vehicle is equipped with engine immobilizer system, 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.