Series 50G/60G Troubleshooting – Section 1.2 Vehicle Condition

Section 1.2
Vehicle Condition

Obvious part and component problems may cause a No Start condition. The first step in diagnosing the engine is to check related vehicle conditions.‪

Section 1.2.1
Troubleshooting the Vehicle

To ensure obvious part and component problems are not causing a No Start 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 parking brake is engaged and the transmission is in neutral during cranking.
   5. Confirm the manual gas valve is open during cranking.
   6. Confirm the fuel door is closed.
   7. If the engine still does not start, go to step .
   8. If the engine starts, 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 the fuel door magnetic switch. Refer to OEM Vehicle Manual.
   7. Confirm proper operation of all tank valves and high pressure solenoid valve during cranking. 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 does not start, go to step .
   11. If the engine starts, 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 does not start, check the active DDEC diagnostic codes. Refer to "1.3 Active DDEC Diagnostic Codes" .
   3. If the engine starts, troubleshooting is done.