BOLT 1B2721 - Caterpillar

3176, 3406B (PEEC) Truck EnginesDescription of Change: A pedal-mounted throttle sensor is now available for 3176 and 3406B (PEEC) Truck engines. (The throttle position sensor under the cab is also still available.) The new sensor has the electronics on the back of the OEM-supplied pedal. The personality module has been updated on all these truck engines to accommodate the new sensor, even if it is not used.Adaptable To: The new pedal-mounted throttle sensor (7X1930 Control Group) can be installed in place of the throttle position sensor (7T5596 Control Group) on earlier truck engines. A new personality module is required if the engine was built before May 15, 1989. Calibration of the pedal-mounted sensor (7X1930) is done automatically by the ECM (Electronic Control Module). The correct calibration can be displayed with the ECAP (Electronic Control Analyzer Programmer) or the DDT (Digital Diagnostic Tool). The correct per cent throttle (governor control movement) is displayed as 3% with the throttle completely released, and 100% with the throttle completely depressed.
Calibration of the throttle position sensor (7T5596) must still be done manually. However, instead of using the percent throttle reading displayed with an ECAP or DDT, use the frequency probe to monitor the pulse width modulated signal (PWM, or duty cycle) on the ECAP or DDT. To do this, install a 9-pin breakout "T" (P7/J7 for 3176 or P2/J2 for 3406B PEEC) and monitor PWM on the THROTTLE signal line (pin E for both engines) using an ECAP or DDT. Set the minimum throttle position when the duty cycle reading is 18 to 20%, and set the maximum throttle position when the duty cycle reading is 81 to 83%.