PIN 2G8609 - Caterpillar

System Operation Description:Use this procedure if another procedure has directed you here. Use this procedure if any of the following diagnostic codes are active:
91-02 Throttle Position Sensor erratic, intermittent, or incorrect
91-03 Throttle Position Sensor voltage above normal
91-04 Throttle Position Sensor voltage below normal
91-12 Accelerator pedal - power supply failure
774-02 Secondary Throttle Position Sensor erratic, intermittent, or incorrect
774-03 Secondary Throttle Position Sensor voltage above normal
774-04 Secondary Throttle Position Sensor voltage below normal
774-12 Secondary Throttle Position Sensor failureThe Throttle Position Sensor (TPS) is an analog sensor and this sensor is attached directly to the throttle assembly. Foot or hand operated versions of the throttle assembly are available. The throttle position sensor provides an output voltage to the Electronic Control Module (ECM). The sensor output voltage will vary with the position of the throttle from 0.5 Volts to 4.5 Volts.The sensor receives +5 Volt power from the ECM. The sensor will produce a voltage that will alter between low idle and high idle. The voltage is changed into a throttle position within the range 0 to 100 percent by the ECM. The output voltage from the sensor is displayed on the electronic service tool as a percentage:
0.5 Volts = 5 percent
4.5 Volts = 95 percentThe TPS senses the speed requirement from the throttle position. A second TPS may override the speed requirement from the first TPS. This override will be subject to an input from either the SAE J1939 (CAN) or from the Set Speed Control. The input status can be checked on the electronic service tool Status Display Screen.The system will check the position of the idle validation switch in relation to the throttle position signal when the idle validation has been set for use. If the switch position and the signal from the TPS are valid, then the throttle will operate as normal.
Illustration 1 g01331438
Schematic of the analog throttle position sensor (31 Pin MIC)
Illustration 2 g01331437
Schematic of the analog throttle position sensor (70 Pin MIC)
Illustration 3 g01625095
ECM pin locations
(18) Throttle 2 Position
(25) Throttle 1 Position
(44) Sensor Common
(45) +5 Volt Supply Test Step 1. Inspect the Electrical Connectors and the Wiring
Turn the keyswitch to the OFF position.
Check the connectors and wiring for the following problems: damage, abrasion, corrosion and incorrect attachment.
Refer to Troubleshooting, "Electrical Connectors - Inspect".
Perform a 45 N (10 lb) pull test on each of the wires in the harness that are associated with the throttle position sensor. Check the wire connectors at the ECM, at the MIC, and at the throttle assembly.
P1:18 Throttle No 2
P1:25 Throttle No 1
P1:44 Sensor common
P1:45 +5V DC sensor supply
Check the ECM connector (Allen head screw) for the proper torque of 6.0 N m (55 lb in). Expected Result:The connectors and wiring should be free of the following faults: damage, abrasion, corrosion and incorrect attachment.Results:
OK - Proceed to Test Step 2.
Not OK - Repair: Repair the connectors or wiring and/or replace the connectors or wiring.Use the electronic service tool to clear all logged diagnostic codes and then verify that the repair has eliminated the fault.STOPTest Step