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Home >> Jeep >> 1996 >> Grand Cherokee Limited, 5.2 Y >> Repair and Diagnosis >> External Pages >> Different car >> Section 180 (Engine Controls - Tests W/Codes - 4.0L) >> Self-Diagnostic Tests >> Test TC-27A - Auto Shutdown Relay Control Circuit (DTC 42)

Test TC-27A - Auto Shutdown Relay Control Circuit (DTC 42)

WARNING: This page is about a different car, the 1995 Jeep Wrangler, 1995 Jeep Grand Cherokee, and 1995 Jeep Cherokee. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: Perform TEST TC-1A  before proceeding with this test. For connector terminal identification, see CONNECTOR IDENTIFICATION  at beginning of article. For wiring diagrams, see WIRING DIAGRAMS  at the end of this article. Perform TEST VER-2A  after each repair.
  1. Using scan tool, actuate Auto Shutdown (ASD) relay. If ASD relay is clicking, go to next step. If ASD relay is not clicking, go to step 5).
  2. Condition required to set trouble code is not present at this time. AUTO SHUTDOWN RELAY CONTROL CIRCUIT trouble code sets if an open or short is detected in Auto Shutdown (ASD) relay control circuit. Possible causes are: open or short in ASD relay coil, open or short in ASD relay ignition feed, open or shorted ASD relay control circuit, failed PCM driver, PCM failure, or defective or damaged connector terminals or wires. Go to next step.
  3. Inspect all related wiring and connectors and repair as necessary. If no problems were found with wiring and connectors, go to next step.
  4. While still actuating ASD relay, wiggle wiring harness from ASD relay to Powertrain Control Module (PCM). If engine dies, repair wiring as necessary. If engine did not die, see INACTIVE DTC CONDITION  in this article. Test is complete.
  5. Remove ASD relay and ensure connector is clean and not damaged. Using scan tool in voltmeter mode, check voltage on ASD relay connector, fused ignition feed circuit (Dark Blue wire on XJ body, White/Yellow wire on YJ body or Light Blue/Red wire on ZJ body). If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in fused ignition feed circuit (Dark Blue wire on XJ body, White/Yellow wire on YJ body or Light Blue/Red wire on ZJ body).
  6. Turn ignition off. Disconnect PCM 60-pin connector and ensure connector is clean and not damaged. Using scan tool in ohmmeter mode, check resistance of ASD relay connector, relay control circuit (Dark Blue/Yellow wire on XJ and YJ bodies or Pink wire on ZJ body). If resistance is more than 5 ohms, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Blue/Yellow wire on XJ and YJ bodies or Pink wire on ZJ body.
  7. Using an external ohmmeter, check resistance of ASD relay control circuit (Dark Blue/Yellow wire on XJ and YJ bodies or Pink wire on ZJ body) between ASD relay connector and PCM connector terminal No. 51. If resistance is more than 5 ohms, repair open in Dark Blue/Yellow wire on XJ and YJ bodies or Pink wire on ZJ body. If resistance is less than 5 ohms, replace PCM.
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