STC500 Crane operation room throttle pedal Don't work Trouble Shooting Case。

Repair Procedure：

1: throttle switch, power switch open 115 ground wire - conductive ring 207- bridge 207- engine ECM07 08 interface, 0V switch throttle.
2: The accelerator pedal through the wiring harness and SYMC is linked together, SYMC acquisition throttle signal (0 ~ 5 v voltage signal), SYMC according to the amount of voltage acquisition, send the analog current signal, passed to chassis wiring harness, conductive ring through the pulldown resistor is converted into a voltage signal, the engine ECU throttle pin connected signal, ECU according to the voltage signal to control the engine speed. 
Detection method:

1. Check whether there is throttle and switch fault.
1-1 find 207 in the cab, normal
2-2 207 is from the boarding car 115 0V, the detection found that 115 is a virtual ground wire, resulting in the inability to transfer 0V to 207.The inspection found that the customer replaced the conductive ring and connected the chassis ground wire incorrectly.(see attached photo)