3.
Check the vehicle speed after connecting a scantool to Data Link Cable(DLC).
ECM is received Vehicle Speed Signal from ABS module. Wheel sensor signal is input to ABS module. ABS module send this signal to ECM. If vehicle speed signal is not input to ECM when vehicle is being stopped, engine stalls because ECM doesn`t control ignition timing and fuel injection. The purpose of the inspection is to analyze whether vehicle speed signal is input to ECM or not.
Engine "ON"
Drive the vehicle after lifting the vehicle.
Check the vehicle speed after connecting a scantool to Data Link Cable(DLC).
Is the vehicle speed current data normal?
YES
Vehicle speed signal is OK.
NO
Go to "Vehicle speed signal inspection" procedure as below..
Engine "ON"
Check the waveform of the vehicle speed signal. (Measure terminal "4" of the MC 11 connector as Fig2.)
Drive the vehicle after lifting the vehicle.
Is the waveform of the vehicle speed signal normal?
YES
Vehicle speed signal is OK.
NO
If harness is OK, Check ABS/TCS module.
The vehicle speed signal input to ECM is not VSS(Vehicle Speed Sensor) but wheel speed sensor signal of the FR(Front Right) wheel. ABS module send 12V pulse signal to ECM.
