Camry CNG Models, Camry Gasoline Models With Manual A/C & Camry Solara With Manual A/C
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 suspect, repair and repeat testing to confirm ECM malfunction. On Camry gasoline models and Camry Solara with engine immobilizer, if ECM is replaced, ECM must be programmed with proper ignition key code for engine immobilizer system. For programming procedures, see COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION, or appropriate ENGINE IMMOBILIZER SYSTEMS article in ACCESSORIES & EQUIPMENT.
- Check A/C compressor drive belt for proper adjustment. See SERVICE & ADJUSTMENT SPECIFICATIONS article for proper drive belt tension. If A/C compressor drive belt is properly adjusted, go to next step. If A/C compressor drive belt requires adjustment, adjust drive belt to specification and 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 some models, it may be necessary to replace A/C compressor along with A/C compressor lock sensor.
- Remove glove box for access to ECM. For illustration of ECM location, see THEORY & OPERATION article. 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 FOR A/C COMPRESSOR LOCK SENSOR table. These are the LCK1 and E1 terminals at ECM.ECM TERMINAL IDENTIFICATION FOR A/C COMPRESSOR LOCK SENSOR
Application ECM Connector ECM Terminal No. (Wire Color) Camry CNG Models E7 26 (White/Blue) E6 17 (Brown) Gasoline Models With Engine Immobilizer E11 25 (White/Blue) E10 17 (Brown) Without Engine Immobilizer E11 26 (White/Blue) E10 17 (Brown) Camry Solara With Engine Immobilizer E11 25 (White/Blue) E10 17 (Brown) Without Engine Immobilizer E11 26 (White/Blue) E10 17 (Brown) - 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 some models, it may be necessary to replace A/C compressor along with A/C compressor lock sensor.
- Check wiring harness and electrical connectors between ECM and A/C compressor lock sensor. See WIRING DIAGRAMS in MANUAL A/C-HEATER SYSTEMS - CAMRY & CAMRY SOLARA article in AIR CONDITIONING & HEATING. 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.