Test A: Powertrain Control Module (Pcm) Does Not Respond To NGS Tester
NOTE:
Depending on module configuration, with all modules connected and with ignition switch in RUN position or with engine running 2-3 volts may be present at Data Link Connector (DLC) terminals No. 2 (Gray wire without traction control; Gray/Violet wire with traction control) and No. 10 (Blue wire without traction control; Blue/White wire with traction control). These are the Standard Corporate Protocol (SCP) diagnostic communications network circuits.
- Turn ignition switch to LOCK position. Disconnect NGS tester. Disconnect PCM harness connector C421. Inspect connector for loose, damaged or corroded terminals. If connector is okay, go to next step. If connector is damaged, repair connector as necessary.
- Measure resistance between terminal No. 16 (Gray wire) at PCM harness connector C421 and terminal No. 2 (Gray wire without traction control; Gray/Violet wire with traction control) at Data Link Connector (DLC). See Fig 1 and Fig 2 . If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in Gray/Violet and/or Gray wire between DLC and PCM.
- Measure resistance between terminal No. 15 (Blue wire) at PCM harness connector C421 and terminal No. 10 (Blue wire without traction control; Blue/White wire with traction control) at DLC. If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, open in Blue and/or Blue/White wire.
- Disconnect Anti-Lock Brake System (ABS) module harness connector C385 (if equipped with traction control). Turn ignition switch to RUN position. Measure voltage at terminal No. 2 (Gray wire without traction control; Gray/Violet wire with traction control) at DLC. If voltage does not exist, go to next step. If voltage exists, repair short to voltage in Gray and/or Gray/Violet wire.
- Turn ignition switch to LOCK position. Measure resistance between ground and terminal No. 2 (Gray wire without traction control; Gray/Violet wire with traction control) at DLC. If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Gray and/or Gray/Violet wire.
- Turn ignition switch to RUN position. Measure voltage at terminal No. 10 (Blue wire without traction control; Blue/White wire with traction control) at DLC. If voltage does not exist, go to next step. If voltage exists, repair short to voltage in Blue and/or Blue/White wire.
- Turn ignition switch to LOCK position. Measure resistance between ground and terminal No. 10 (Blue wire without traction control; Blue/White wire with traction control) at DLC. If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in Blue and/or Blue/White wire.
- If vehicle is equipped with traction control, go to next step. If vehicle is not equipped with traction control, replace PCM if PCM power and ground circuits are okay.
- Connect ABS module harness connector C385. Measure resistance between ground and terminal No. 2 (Gray/Violet wire) at DLC. If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, replace ABS module.
- Measure resistance between ground and terminal No. 10 (Blue/White wire) at DLC. If resistance is greater than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, replace ABS module.
- Turn ignition switch to RUN position. Measure voltage at terminal No. 10 (Blue/White wire) at DLC. If voltage is 6 volts or less, go to next step. If voltage is greater than 6 volts, replace ABS module.
- Measure voltage at terminal No. 2 (Gray/Violet wire) at DLC. If voltage does not exist, replace PCM if PCM power and ground circuits are okay. If voltage exists, replace ABS module.