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Home >> GMC >> 1991 >> Value Van 7.4 N >> Repair and Diagnosis >> External Pages >> Different car >> Section 24 (Engine Controls - Tests W/Codes - 2.5L) >> No-Start Tests >> Test NS-1A - Qualifying No Start Condition

Test NS-1A - Qualifying No Start Condition

WARNING: This page is about a different car, the 1995 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION: When checking for spark, Powertrain Control Module (PCM) damage may occur if spark plug cable is held more than 1/4" away from ground.
NOTE: For circuit and connector terminal identification, see CONNECTOR IDENTIFICATION . For wiring diagrams, see WIRING DIAGRAM  section.
  1. Attempt to crank engine. If engine does not crank, go to TEST NS-9A. If engine cranks, turn ignition off. Disconnect any spark plug cable at spark plug. Insert an insulated screwdriver in spark plug cable terminal. Hold screwdriver within 1/4" of ground.
    NOTE: When checking for spark, consider one or two sparks as a no-spark condition.
  2. While cranking engine for 10 seconds, watch for spark. If a good spark occurs, go to TEST NS-2A. If a good spark does not occur, turn ignition off. Reconnect spark plug cable. Disconnect ignition coil wire from distributor. Hold coil wire within 1/4" of ground. While cranking engine for 10 seconds, watch for spark.
  3. If good spark occurs, repair secondary ignition system as necessary. Perform TEST VER-1. If a good spark does not occur, turn ignition off. Remove ignition coil wire. Using an external ohmmeter, check resistance of ignition coil wire.
  4. If resistance is more than 15 k/ohms, replace ignition coil wire. Perform TEST VER-1. If resistance is less than 15 k/ohms, remove distributor cap. While watching distributor rotor, crank engine. If rotor does not turn, repair distributor drive system. Perform TEST VER-1.
  5. If rotor turns, reinstall distributor cap. Reinstall ignition coil wire. Disconnect ignition coil electrical connector. Inspect all terminals. Repair as required. Perform TEST VER-1. If terminals are okay, turn ignition on. Using scan tool, actuate Auto Shutdown (ASD) relay.
  6. Put scan tool in voltmeter mode. Using scan tool, check voltage on ignition coil connector Dark Green/Orange wire. If voltage is less than 10 volts, repair open Dark Green/Orange wire. Perform TEST VER-1.
  7. If voltage is more than 10 volts, check voltage on ignition coil connector Gray wire. If voltage is more than 10 volts, replace ignition coil. Perform TEST VER-1. If voltage is less than 10 volts, turn ignition off.
  8. Disconnect Powertrain Control Module (PCM) connector. Put scan tool in ohmmeter mode. Using scan tool, check resistance of PCM connector terminal No. 19 Gray wire. If resistance is less than 5 ohms, repair open in appropriate wire. Perform TEST VER-1.
  9. If resistance is more than 5 ohms, using an external ohmmeter, check resistance of Gray wire between ignition coil connector and PCM connector terminal No. 19. If resistance is more than 5 ohms, repair open in appropriate wire. Perform TEST VER-1. If resistance is less than 5 ohms, replace PCM. Perform TEST VER-1.
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