Test B: Scan Tool Does Not Communicate With Class 2 Device
- Connect scan tool to Data Link Connector (DLC). DLC is located under instrument panel, near steering column. Turn ignition switch to RUN position. If scan tool powers up, go to next step. If scan tool does not power up, perform TEST A: SCAN TOOL DOES NOT POWER UP .
- Using scan tool, attempt to establish communication with Powertrain Control Module (PCM). If communication is not established with PCM, go to next step. If communication is established with PCM, class 2 serial data line may have an intermittent open short to voltage or short to ground.
- Turn ignition switch to LOCK position. Disconnect scan tool from DLC. Check for poor terminal connection or tension at DLC terminals No. 2 (Purple wire) and No. 5 (Black wire). See Figure. If problem does not exist, go to next step. If problem exists, repair as necessary. After repairs, perform appropriate diagnostic system check for any malfunctioning system(s). See DIAGNOSTIC SYSTEM CHECK INDEX table under SELF-DIAGNOSTIC SYSTEM.
- Check for open in Black wire between ground and DLC terminal No. 5. Ground point is located behind instrument panel, on right side of brake pedal bracket. If problem does not exist, go to next step. If problem exists, repair as necessary. After repairs, perform appropriate diagnostic system check for any malfunctioning system(s). See DIAGNOSTIC SYSTEM CHECK INDEX table under SELF-DIAGNOSTIC SYSTEM.
- Disconnect PCM harness connector C1. PCM is located in passenger side of engine compartment, in front of strut tower. Check Purple wire for short to ground and short to voltage between DLC terminal No. 2 and PCM harness connector C1 terminal No. 59. See Figure and Fig 1 . If problem does not exist, go to next step. If problem exists, repair as necessary. After repairs, perform appropriate diagnostic system check for any malfunctioning system(s). See DIAGNOSTIC SYSTEM CHECK INDEX table under SELF-DIAGNOSTIC SYSTEM.
- Check for open or short to ground in PCM battery voltage and ignition voltage circuits. See IDENTIFYING PCM BATTERY VOLTAGE & IGNITION VOLTAGE CIRCUITS table. If no problem exists, go to next step. If any problem exists, repair as necessary. After repairs, perform appropriate diagnostic system check for any malfunctioning system(s). See DIAGNOSTIC SYSTEM CHECK INDEX table under SELF-DIAGNOSTIC SYSTEM.IDENTIFYING PCM BATTERY VOLTAGE & IGNITION VOLTAGE CIRCUITS
Terminal No. (Connector) Wire Color Circuit 19 (C1) Pink (1) Ignition 20 (C1) Orange (2) Battery (1) Battery voltage should exist with ignition switch in RUN and START positions. (2) Battery voltage should exist at all times. - Turn ignition switch to LOCK position. Check for open in PCM ground circuits. See IDENTIFYING PCM GROUND CIRCUITS table. If problem does not exist, go to next step. If problem exists, repair as necessary. Ground point is located on lower left front of engine on transaxle stud, near starter. After repairs, perform appropriate diagnostic system check for any malfunctioning system(s). See DIAGNOSTIC SYSTEM CHECK INDEX table under SELF-DIAGNOSTIC SYSTEM.IDENTIFYING PCM GROUND CIRCUITS
Terminal No. (Connector) Wire Color Circuit 16 (C1) Black/White Ground 56 (C1) Black/White Ground 57 (C1) Black/White Ground 60 (C1) Black/White Ground - Check Purple wire for open between DLC terminal No. 2 and PCM harness connector C1 terminal No. 59. See Figure and Fig 1 . If problem does not exist, go to next step. If problem exists, repair as necessary. After repairs, go to step 11.
- Check for poor terminal connection or tension at PCM harness connector C1 terminals No. 59 (Purple wire). If problem does not exist, go to next step. If problem exists, repair as necessary. After repairs, go to step 11.
- Replace PCM. See POWERTRAIN CONTROL MODULE under REMOVAL & INSTALLATION.
- Connect PCM harness connectors. Connect scan tool to DLC. Turn ignition switch to RUN position. Wait 10 seconds. Using scan tool, attempt to establish communication with PCM. If communication is established with PCM, go to next step. If communication is not established with PCM, go to step 3.
- Using scan tool, select DISPLAY DTC function for PCM. Record all DTCs displayed and their status. If any DTCs are displayed, go to next step. If no DTCs are displayed, go to step 14.
- Perform appropriate test in accordance with DTCs retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. After repairs, go to next step.
- Using scan tool, clear all DTCs. Using scan tool, select DISPLAY DTC function for PCM. If any DTCs are displayed, perform appropriate test in accordance with DTCs retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If no DTCs are displayed, system is okay at this time.