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HOMESERVICE MANUALSJEEP1994WRANGLER SAHARA, AUTOMATIC, 32RHREPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMENGINE CONTROLS - TESTS W/CODES - 2.5L & 4.0LSELF-DIAGNOSTIC TESTSTEST TC-28A - NO ASD RELAY VOLT SENSE AT PCM(DTC 42)
1994 Jeep Wrangler Sahara, Automatic, 32RH

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

1994 Jeep Wrangler Sahara, Automatic, 32RHSECTION Test TC-28A - No ASD Relay Volt Sense At Pcm(DTC 42)
NOTE: For connector terminal identification, see CONNECTOR IDENTIFICATION at beginning of article. For wiring diagrams, see WIRING DIAGRAMS at the end of this article.
  1. Using DRB, erase trouble code messages. Attempt to start engine and let it idle. Read trouble code messages. If DRB 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 when ASD relay is energized. Possible causes are: open ASD relay output wire (Dark Green/Orange wire), open ASD relay control circuit wire (Dark Blue/Yellow), failed ASD relay or open battery feed circuit to ASD relay (Red wire). Go to next step.
  3. Inspect all related wiring and connectors and repair as necessary. Perform TEST VER-1. If no problems were found with wiring and connectors, see INACTIVE DTC CONDITION in this article. Perform TEST VER-1. Go to next step.
  4. With engine running, wiggle harness from ASD relay to PCM. Using DRB, 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.
  5. Using DRB, erase trouble code messages. Attempt to start engine. If engine does not start, go to step 7). If engine starts, turn ignition off and disconnect Powertrain Control Module (PCM). Using an external ohmmeter, measure resistance in Auto Shutdown (ASD) circuit (Dark Green/Orange wire) between PCM connector terminal No. 57 and ASD relay. See Figure .
  6. If resistance is greater than 5 ohms, repair open in Dark Green/Orange wire. Perform TEST VER-1. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-1.
  7. If engine does not start, disconnect ASD relay. Inspect all related wiring and connectors and repair as necessary. Using DRB in voltmeter mode, check voltage in battery feed circuit (Red/White wire). If voltage is less than 10 volts, repair open in Red/White wire. Perform TEST VER-1.
  8. If voltage is greater than 10 volts, turn ignition off. Install a known good relay. and attempt to start engine. If engine starts, replace original ASD relay. Perform TEST VER-1. If engine does not start, disconnect Powertrain Control Module (PCM). Using an external ohmmeter, measure resistance in Auto Shutdown (ASD) circuit (Dark Green/Orange wire) between PCM connector terminal No. 57 and ASD relay. See Figure .
  9. If resistance is greater than 5 ohms, repair open in Dark Green/Orange wire. Perform TEST VER-1. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-1.
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