Failure Discription：Engine cannot start. Dismount display indicates engine communication timeout
Failure Analyce & Trouble shooting：
1 .ECU insurance damage
2.The flameout relay is damaged
3. The bridge wiring harness and ECU loosen the plug-in (resulting in the failure of 143.144 bus)
4. The flameout switch on board is damaged
5.The ECU body is damaged
Repair Procedure：
1.Check that the engine ECU power supply insurance in the electric control cabinet in the cab is normal and not damaged
2.Check the flameout relay in the electronic control cabinet for normalcy and exchange it with other relays. The alarm fault is still unresolved
3.Check that the vehicle wiring harness and engine ECU in the cab do not loosen the plug-in and wiring harness is not damaged
4.Check that the flameout switch on the vehicle is reset normally
5.Disconnect the conductive ring connection between the upper and lower car, start the engine and still cannot start, the fault is still unresolved
6.Get off on the electricity, the engine ECU power plug, power cord plug is measured with a multimeter with 24 v normal, ground wire is normal, check the engine ECU another plug, pull out inspection Angle of 45 needle without electricity, only 5 v plug in measurement, identified as electricity, disassemble the corrugated pipe along the wire harness search, found that the ECU plug wire into the water in the former period led to internal wiring harness corrosion in empty pick up, after the reconnect engine starting, normal fault alarm disappear 

Principle & Expierence Summary：First solve the obvious and existing fault, from simple to difficult method to solve the fault