Data Link Connector (DLC) Diagnosis
NOTE:
Main relay is located behind instrument panel, to left of glove box.
- If OBD system check has been performed, go to next step. If OBD system check has not been performed, go to ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK .
- Connect scan tool to data link connector. Turn ignition switch to RUN position. If scan tool does not display engine data, go to next step. If scan tool displays engine data, data link connection is okay at this time. Check for loose and intermittent connections.
- Check FI, IG-COIL METER and TAIL-DOME fuses. If all fuses are okay, go to next step. If any fuse(s) were blown, repair as necessary and go to step 21 .
- Turn ignition switch to RUN position. Measure voltage at terminal No. 16 (White wire) of data link connector. See Fig 1 . If battery voltage exists, go to next step. If battery voltage does not exist, go to step 7 .
- Measure voltage at terminal No. 7 at data link connector. If battery voltage exists, go to next step. If battery voltage does not exist, go to step 8 .
- Using a test light connected to battery voltage, probe terminals No. 4 and 5 at data link connector. If test light illuminates at each terminal, go to step 20 . If test light does not illuminate at both terminals, go to step 9 .
- Repair open or short in battery voltage circuit (White wire) between instrument panel fuse box and data link connector. After repairs have been made, go to step 21 .
- Check for open or short in serial data circuit between PCM and data link connector. If open or short exists, repair as necessary and go to step 21 . If open or short does not exist, go to step 10 .
- Repair open in ground circuits and go to step 21 .
- Turn ignition switch to RUN position. Using a test light connected to ground, backprobe ignition voltage circuits terminals at PCM. See PCM CIRCUITS (1.6L) table or PCM CIRCUITS (1.8L) table under PCM CIRCUIT IDENTIFICATION. If test light did not illuminate at both terminals, go to next step. If test light illuminated at both terminals, go to step 19 .
- Check for open or short in ignition voltage circuits between PCM and main relay. If open or short does not exist, go to next step. If open or short exists, repair as necessary and go to step 21 .
- Turn ignition switch to LOCK position. Remove main relay. Turn ignition switch to RUN position. Using a test light connected to ground, probe terminal No. 2 (Black/Red wire) at main relay harness connector. See Fig 2 . If test light illuminates, go to next step. If test light does not illuminate, go to step 15 .
- Using a test light connected to ground, probe terminal No. 1 (Black/White wire) at main relay harness connector. If test light illuminates, go to next step. If test light does not illuminate, go to step 16 .
- Turn ignition switch to LOCK position. Using a test light connected to battery voltage, probe terminal No. 3 (Blue wire) at main relay harness connector. Turn ignition switch to RUN position. If test light illuminates, go to step 18 . If test light does not illuminate, go to step 17 .
- Repair open or short in power feed circuit (Black/Red wire) between main relay and FI fuse. After repair has been made, go to step 21 .
- Repair open or short in ignition feed circuit (Black/White wire) between main relay and IG-COIL METER fuse. After repair has been made, go to step 21 .
- Check for an open in main relay control circuit between main relay and PCM. If an open does not exist, go to step 19 . If an open exists, repair as necessary and go to step 21 .
- Replace main relay and go to step 21 .
- Replace PCM and go to step 21 .
- Scan tool is faulty. Refer to scan tool manual for repair information, then go to next step.
- Operate vehicle within conditions which original symptom was noted. If system operates properly, system is okay at this time. If system does not operate properly, check harness connectors for poor connection.