677:3 Starter Relay Drive Circuit - Voltage Above Normal, or Shorted to High SourceRelated models 
The Engine Control Module has detected a break in the relay driver circuit or relay coil. Note: This knowledge base article is for JLG series machines that uses Diesel Exhaust Fluid. Starter Lockout Driver Circuit - Voltage Above Normal or Shorted to a High Source Possible CausesDefective relay
Defective wiring harness
Bad Ground Connection
Defective ECM Troubleshooting Steps1. Locate the fuse and relay panel beside the battery disconnect switch in the engine compartment and remove the R1 Starter Lockout Relay. (note the orientation when removing the relay)
2. Perform a continuity check between pin 86 and pin 85 to see if the relay coil is good.
A. If there is no continuity, replace the relay.
3. Locate the ECM mounted to the frame wall just behind the engine radiator and disconnect the J2 X771 connector. 4. Perform a continuity check on wire WHT 84 START LO TXL pin 83 of the X771 connector to socket 86 of the R1 Starter Lockout Relay.
A. If there is no continuity, repair the wire.
5. Perform a continuity check on wire BLK 0-26-11 GND socket 85 of the R1 Starter Lockout Relay and the X775 located at the ground bussbar located on the frame wall behind the transmission.
A. If there is no continuity, repair the wire.
6. If everything above checks out good, Cummins will need to verify the ECM is performing correctly.
- Cummins Analyzer Kit
- Standard Mechanical Tools
- Fluke Multimeter
Related DocumentsService Manual
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