RING-BACKUP 1140706 - Caterpillar

System Operation Description:Use this procedure if any of the following diagnostic codes are active:
0091-03 Throttle Position Sensor voltage above normal
0091-04 Throttle Position Sensor voltage below normal
0774-03 Secondary Throttle Position Sensor voltage above normal
0774-04 Secondary Throttle Position Sensor voltage below normalThe diagnostic codes above relate to an analog sensor. Use this procedure only if the analog sensor is a variable resistance potentiometer sensor.The sensor is most likely to be mounted on a throttle pedal. The sensor is attached directly to the throttle assembly. The sensor provides an output voltage to the Electronic Control Module (ECM). The sensor output voltage will vary with the position of the throttle. Foot operated or hand operated throttle assemblies are available.The sensor receives +5 Volt DC power from the ECM. The sensor will produce a raw signal voltage that will alter between low idle and high idle. The voltage is changed into a throttle position within the range 0% to 100% by the ECM.The sensor senses the speed requirement from the throttle position. A second sensor may override this speed requirement from the first sensor. This override will be subject to an input from a secondary throttle or from the SAE J1939 (CAN) data link or from a PTO control.Use the electronic service tool in order to check the input status.
Table 1
P1 Pin Connections    
Function     Throttle 1     Throttle 2    
+5 Volt DC Supply     41     42    
Sensor Ground     33     34    
Throttle Position Input     54     55    
Illustration 1 g01800755
Schematic of the analog throttle demand sensors
Illustration 2 g01800768
Typical view of the P1 connector pin locations (33) Sensor Ground (GND) (34) Sensor Ground (GND) (41) Sensor supply (5V) (42) Sensor supply (5V) (54) Analog throttle input 1 (55) Analog throttle input 2Test Step 1. Check for Connector Damage
Turn the keyswitch to the OFF position.
Check the connectors and the harness for the following faults: 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 demand sensor. Check the wire connectors at the ECM and at the throttle sensor. The wire connectors are shown in table 1.
Check the screw for the ECM connector for the correct torque of 5.0 N m (44 lb in).Expected Result:The connectors and the harness 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 the harness and/or replace the connectors or the harness. Use the electronic service tool in order to clear all logged diagnostic codes and then verify that the repair eliminates the fault.STOPTest Step 2. Check for Active Diagnostic Codes
Turn the keyswitch to the ON position.
Use the electronic service tool to check for diagnostic codes.Expected Result:RESULT 1 The electronic service tool displays the following active diagnostic codes or recently logged diagnostic codes:
91-3 Throttle Position Sensor voltage above normal
91-4 Throttle Position Sensor voltage below