Test J: Electronic Automatic Temperature Control (EATC) Module Does Not Respond To NGS Tester
NOTE:
After making any repair, perform data link diagnostic test. See DATA LINK DIAGNOSTIC TEST under SELF-DIAGNOSTIC SYSTEM.
- Turn ignition switch to LOCK position. Electronic Automatic Temperature Control (EATC) module has two 13-pin connectors. Disconnect EATC module 13-pin connector C280, located behind center of instrument panel. Connector C280 has a blank terminal No. 5. See Fig 1. Inspect EATC module connector C280 for loose, damaged or corroded terminals. Repair as necessary. If connectors are okay, go to next step.
- Connect EATC module connector C280. Perform data link diagnostic test. See DATA LINK DIAGNOSTIC TEST under SELF-DIAGNOSTIC SYSTEM. If NGS tester displays EATC: NO RESPONSE ON CKT914 (BUS+), go to next step. If NGS tester displays EATC: NO RESPONSE ON CKT914 (BUS-), go to step 4.
- Turn ignition switch to LOCK position. Disconnect NGS tester. Disconnect EATC module 13-pin connector C280. Measure resistance of Tan/Orange wire between EATC module connector C280 terminal No. 15 and Data Link Connector (DLC) terminal No. 2. See Figure and Fig 1 . If resistance is less than 5 ohms, replace EATC module. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. If resistance is 5 ohms or more, repair open in Tan/Orange wire between EATC module connector and DLC.
- Turn ignition switch to LOCK position. Disconnect NGS tester. Disconnect EATC module 13-pin connector C280. Measure resistance of Pink/Light Blue wire between EATC module connector C280 terminal No. 1 at and DLC terminal No. 10. See Figure and Fig 1 . If resistance is less than 5 ohms, replace EATC module. See appropriate AUTOMATIC A/C-HEATER SYSTEMS article in AIR CONDITIONING & HEATING. If resistance is 5 ohms or more, repair open in Pink/Light Blue wire between EATC module connector and DLC.