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Home › Dodge and Ram › 2003 › Ram Van B2500, Van Cargo Extended, 5.2 T › Repair and Diagnosis › Engine Performance › System › Engine Controls - System & Component Testing - CNG › DRIVEABILITY Problems › Start & Stall Condition

Start & Stall Condition

NOTE: For circuit identification and wiring diagram, see WIRING DIAGRAMS  . If Powertrain Control Module (PCM) is replaced, PCM must be reprogrammed. See PROGRAMMING. After each repair procedure has been completed, reconnect all components. Perform POWERTRAIN VERIFICATION TEST VER-1 under VERIFICATION TESTS in SELF-DIAGNOSTICS - RAM VAN article.

Possible Causes:

Testing

  1. Turn ignition on. Using scan tool, check for DTCs. If no DTCs exist, go to next step. If any DTCs exist, perform appropriate diagnostic test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in SELF-DIAGNOSTICS - RAM VAN article.
  2. Turn ignition on. Using scan tool, monitor TP sensor voltage while slowly opening throttle from idle position to wide open throttle position. If voltage changes smoothly, go to next step. If voltage does not change smoothly, replace TP sensor.
  3. Ensure throttle is fully closed and against throttle stop. Using scan tool, read TP sensor voltage. If voltage is 0.92 volt or less, go to next step. If voltage is more than 0.92 volt, check for binding throttle linkage. Repair linkage as necessary. If linkage is not binding, replace TP sensor.
    NOTE: The following procedure assumes that the cooling system thermostat is functioning properly. Test works best if performed on a totally cold engine (cold soak).
  4. Turn ignition on. Using scan tool, read Engine Coolant Temperature (ECT) sensor value. If engine coolant temperature is more than 180°F (82°C), allow engine coolant temperature to cool down to 150°F (66°C) before proceeding. If engine coolant temperature is 150°F (66°C) or less, start engine and monitor scan tool until engine coolant temperature reaches 180°F (82°C). If ECT sensor value increases smoothly, go to next step. If ECT sensor value increase is erratic, check for cooling system problems and repair as necessary. If cooling system is okay, replace ECT sensor.
  5. Check the following additional items as possible causes for start and stall condition:
    • Check for any technical service bulletins that may apply.
    • Engine exhaust system must not have restrictions.
    • Engine compression must be within specification.
    • Engine valve timing must be within specification.
    • Engine must not have any vacuum leaks.
    • Throttle body must be free of carbon build-up and dirt.

    If a problem is found, repair as necessary. If no problems are found, go to next step.

  6. Check fuel pressure. See FUEL PRESSURE TEST under FUEL SYSTEMS in BASIC DIAGNOSTICS - RAM VAN - CNG article. If fuel pressure is okay, test is complete. If fuel pressure is not okay, diagnose and repair fuel system as necessary. See FUEL SYSTEMS  .
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