Series 50G & 60G Troubleshooting

Section 3.2 Vehicle Condition

Section 3.2
Vehicle Condition

Obvious part and component problems may cause Low Power, Misfiring, or Rough Running. The first step in diagnosing the engine is to check related vehicle conditions. ‪

Section 3.2.1
Troubleshooting the Vehicle

To ensure obvious part and component problems are not causing Low Power, Misfiring, or Rough Running, troubleshoot as follows:‪

  1. Check the vehicle controls.
    1. Confirm the vehicle has natural gas in its tanks.
    2. Confirm the ignition system is on.
    3. Confirm the batteries are charged.
    4. Confirm the batteries are on.
    5. Confirm the manual gas valve is open during cranking.
    6. Confirm the fuel door is closed.
    7. If the engine still has low power, misfiring, or rough running, go to step .
    8. If the engine operates normally, troubleshooting is done.
  2. Check electrical connections and electronic controls.
    1. Confirm wiring harnesses at DDEC® are connected.
    2. Confirm ground straps from engine to starter are connected.
    3. Confirm the PLC/Multiplex/Electrical System is getting power.
    4. Confirm proper operation of the fire suppression system and the methane detection system. Refer to OEM Vehicle Manual.
    5. Confirm proper operation of the fuel door magnetic switch. Refer to OEM Vehicle Manual.
    6. Confirm proper operation of all tank valves and high pressure solenoid valve during cranking. Refer to OEM Vehicle Manual.
    7. Confirm the following ground wires all are attached to the same ground bar:
    8. Three wires 150 from the five pin vehicle power harness.
    9. Coil ground wire 953 from the coil power harness.
    10. Oxygen Sensor Interface Module ground wire 957 from the OEM sensor ground harness.
    11. Throttle ground wire 956 from the OEM sensor ground harness.
    12. PSV ground wire 150 from the OEM sensor ground harness.
    13. Confirm proper operation of the Stop Engine Light (SEL).
    14. Confirm proper operation of the Check Engine Light (CEL).
    15. If the engine still has low power, misfiring, or rough running, go to step .
    16. If the engine operates normally, troubleshooting is done.
  3. Check the installation requirements for the electronic system.
    1. Verify the installation requirements for the electronic system have been met. Refer to "7 The Natural Gas Engine Characteristics" . If the engine installation requirements for the electronic system did not comply, repair as required.
    2. If the engine still has low power, misfiring, or rough running, check the Ignition System. Refer to "3.3 Ignition System" .
    3. If the engine operates normally, troubleshooting is done.


Series 50G and 60G Troubleshooting Guide - 6SE482
Generated on 10-13-2008

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