Quote:
Originally Posted by SonicVQ
Interesting problem...
From the FSM under P0500:
The vehicle speed signal is sent to the combination meter from the “ABS actuator and electric unit (control unit)” via the CAN communication line.
The combination meter then sends a signal to the ECM via the CAN communication line.
Soooo... the ABS module sends the wheel speed to the gauge cluster (via CAN bus) and it converts it to vehicle speed. The vehicle speed is then sent to the ECU.
It is possible the US cluster sends the vehicle speed in MPH to the ECU. Since the ECU is expecting KPH, it throws off the calculations and s-mode doesn't work.
^^^ just my 2¢
|
Yes. What I posted in his other thread. That's the only thing that bothered me, was no information about MPH or KPH signal to ECM.
That definitely could be the issue, but if such a signal is critical to function of ECM, you would think a Fault or failure would be shown as other systems are looking for a "specific" speed signal.
Not sure if this car (cluster) is smart enough for that.
Either way, I'm not 100% sure.
P.S. I Just looked into FSM a little deeper. In the Cruise control section, vehicle speed is also sent from Combo meter to ECM for CC function. In the system description, Nissan always gives the values as KPH (MPH) which leads me to believe my original theory, that "actual" values are not of concern, only signal pulses from Wheel speed sensors converted to a mechanical/electrical value for speedometer.
From FSM: "BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately
40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.