LEMON Manuals: Even more car manuals for everyone
Home >> Jeep >> 1996 >> Grand Cherokee Limited, 5.2 Y >> Repair and Diagnosis >> External Pages >> Different car >> Section 179 (Engine Controls - Tests W/Codes - 2.5L) >> Self-Diagnostic Tests >> Test TC-28A - No ASD Relay Volt Sense At Pcm (DTC 42)

Test TC-28A - No ASD Relay Volt Sense At Pcm (DTC 42)

WARNING: This page is about a different car, the 1995 Jeep Wrangler 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, read trouble code messages. If scan tool also displays AUTO SHUTDOWN RELAY CONTROL CIRCUIT, go to TEST TC-27A  . Using scan tool, erase trouble code messages. Attempt to start engine and let it idle. Using scan tool, read trouble code messages. If scan tool displays NO ASD RELAY VOLT SENSE AT PCM reset, go to step 5). If trouble code message did not reset, go to next step.
  2. Condition required to set trouble code is not present at this time. NO ASD RELAY VOLT SENSE AT PCM trouble code sets if ASD output voltage is not sensed at PCM when ASD relay is energized. Possible causes are: open ASD relay output circuit (Dark Green/Orange wire), open ASD relay control circuit (Dark Blue/Yellow), failed ASD relay, open fused battery feed circuit to ASD relay (Red wire on Cherokee or Red/White wire on Wrangler), 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, see INACTIVE DTC CONDITION  in this article. Go to next step.
  4. Start engine and allow to idle. Wiggle harness from ASD relay to PCM. Using scan tool, read trouble code messages. If NO ASD RELAY VOLT SENSE AT PCM trouble code message resets, repair wiring where wiggling harness caused code to reset. If NO ASD RELAY VOLT SENSE AT PCM trouble code message does not reset, see INACTIVE DTC CONDITION  in this article. Test is complete.
  5. Using scan tool, erase trouble code messages. Attempt to start engine. If engine does not start, go to step 7). If engine starts, go to next step.
  6. Turn ignition off. Disconnect PCM 60-pin connector and ensure connector is clean and not damaged. Using an external ohmmeter, measure resistance in ASD relay output circuit (Dark Green/Orange wire) between PCM connector terminal No. 57 and ASD relay output. If resistance is more than 5 ohms, repair open in ASD relay output circuit. If resistance is less than 5 ohms, replace PCM.
  7. If engine does not start, disconnect ASD relay and ensure connector is clean and not damaged. Using scan tool in voltmeter mode, check voltage in fused battery feed circuit (Red/Black wire on Cherokee, Red/White wire on Wrangler). If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open in Red/Black wire on Cherokee, Red/White wire on Wrangler.
  8. Turn ignition off. Install a known good relay and attempt to start engine. If engine starts, replace original ASD relay. If engine does not start, go to next step.
  9. Turn ignition off. Disconnect PCM 60-pin connector and ensure connector is clean and not damaged. Using an external ohmmeter, measure resistance in ASD relay output circuit (Dark Green/Orange wire) between PCM connector terminal No. 57 and ASD relay. If resistance is more than 5 ohms, repair open in Dark Green/Orange wire. If resistance is less than 5 ohms, replace PCM.
scientia non olet · About LEMON Manuals