Series 50G & 60G Troubleshooting

Section 8.1 Vehicle Condition

Section 8.1
Vehicle Condition

Obvious part and component problems may cause a backfire condition. The first step in diagnosing the engine is to check related vehicle conditions.‪

Section 8.1.1
Troubleshooting the Vehicle

To ensure obvious part and component problems are not causing a backfire condition, 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 manual gas valve is open during idle.
    5. Confirm the fuel door is completely closed.
    6. If the engine still backfires, go to step .
    7. If the engine no longer backfires, 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 wire 439 in DDEC power harness is not loose.
    4. Confirm the PLC/Multiplex/Electrical System is getting power.
    5. Confirm proper operation of the fire suppression system and the methane detection system. 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 proper operation of fuel door magnetic switch. Refer to OEM Vehicle Manual.
    8. Confirm proper operation of the Stop Engine Light (SEL).
    9. Confirm proper operation of the Check Engine Light (CEL).
    10. If the engine still backfires, go to step .
    11. If the engine no longer backfires, 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 Chapter "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 backfires, check for engine backfire. Refer to "8.2 Backfire" .
    3. If the engine no longer backfires, troubleshooting is done.


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

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