The general manifestations of accelerator control system
disorders are as follows:
(1) Idle jitter or occasional stalling
Engines with accelerator control system
usually cancel idle control valves and are controlled by EPC directly. If there is no problem with spark plug, most of them are caused by dirty electronic throttle. The problem can be solved by cleaning the throttle and setting it basically.
(2) Rear-seating phenomena occur when braking
For EFI engines with electronic throttle, in order to optimize the control of acceleration performance, brake switch status signal, gear signal and air conditioning switch signal are specially transmitted to engine electronic control unit (ECU) to participate in the control of electronic throttle.
(3) Heavy steering, failure code display CAN communication failure
From the principle analysis, the failure of ABS/ASR system is caused not only by the wheel speed sensor, hydraulic controller and brake switch, but also by the device malfunction outside ABS/ASR system, the most typical one is electronic throttle.
(4) Air conditioning system enters failure protection state
The throttle position sensors (G187, G188) are out of order, and the throttle is overstretched due to dirt. The engine electronic control unit (J623) will think that the load is too heavy at this time, and then instruct the cooling fan to continue to run at low speed.