Cummins ISB CM550 (1990-94) Fault Code: 133 PID: 29 SPN: 29 FMI: 3 Remote Throttle Position Sensor

Circuit Description
The remote throttle pedal provides the driver’s throttle command to the electronic control
module (ECM) through the OEM harness and the original equipment manufacturer’s (OEM)
interface harness. The ECM uses this signal to determine the fueling command.

Component Location
The remote throttle pedal location varies with each OEM. Refer to the OEM manual.

Shop Talk
The throttle position sensor is a potentiometer. The resistance specifications of the throttle
position sensor is as follows:
1) Between supply and return = 2000 to 3000 ohms
2) Between supply and signal: Released = 1500 to 3000 ohms; depressed = 200 to 1500

Note: If the throttle or throttle position sensor is changed, or after a calibration download, cycle
the throttle pedal (keyswitch in the ON position) through its complete travel three times. This
procedure calibrates the new throttle with the ECM.
1) The remote throttle enable switch must be turned on for the remote throttle to operate.
2) Possible causes of this fault code include an open circuit in the return wire, short circuit to
+5 VDC or 12 VDC, defective remote throttle position sensor or a failed ECM power
supply.