PUMP GP-ENGINE 0R3538 - Caterpillar

This procedure covers the following codes:
Table 1
Diagnostic Trouble Codes for the Valve Position Sensors
J1939 Code Description Notes
27-3 Engine Exhaust Gas Recirculation Valve Position : Voltage Above Normal The Electronic Control Module (ECM) detects that the signal voltage from the position sensor on the Exhaust Gas Recirculation (EGR) valve is greater than 4.8 VDC for at least 0.5 seconds.
The battery voltage is at least 10 VDC.
The ECM will set the valve to the default position while this code is active. The default position is 0 percent.
The warning lamp will flash. The engine will be derated.
27-4 Engine Exhaust Gas Recirculation Valve Position : Voltage Below Normal The ECM detects that the signal voltage from the position sensor on the EGR valve is less than 0.2 VDC for at least 0.35 seconds.
The battery voltage is at least 10 VDC.
The ECM will set the valve to the default position while this code is active. The default position is 0 percent.
The warning lamp will flash. The engine will be derated.
51-3 Engine Throttle Valve 1 Position : Voltage Above Normal The ECM detects the following conditions:
The signal voltage from the position sensor on the intake throttle valve is greater than 4.75 VDC for at least 0.5 seconds.
The battery voltage is at least 10 VDC.
The intake throttle valve will move to the default position while the diagnostic code is active. The default position is 0 percent.
The warning lamp will come on.
51-4 Engine Throttle Valve 1 Position : Voltage Below Normal The ECM detects the following conditions:
The signal voltage from the position sensor on the intake throttle valve is less than 0.25 VDC for at least 0.5 seconds.
The intake throttle valve will move to the default position while the diagnostic code is active. The default position is 0 percent.
The warning lamp will come on.
Use this procedure in order to troubleshoot the position sensors for the following valves:
EGR valve
Engine intake throttle valveEach position sensor is an integral part of the associated valve. If the following procedure indicates a fault with the position sensor, then the entire valve must be replaced.The following background information is related to this procedure:The troubleshooting procedures for the diagnostic codes of each position sensor are identical. The ECM supplies 5 VDC to terminal "1" of the engine intake throttle valve connector and to terminal "6" of the EGR valve connector. The sensor common from the ECM connector goes to terminal "3" of the engine intake throttle valve connector and to terminal "4" of the EGR valve connector. The sensor supply is output short circuit protected. A short circuit to the battery will not damage the circuit inside the ECM. The signal voltage from terminal "5" of the engine intake throttle valve and from terminal "2" of the EGR valve is supplied to the appropriate terminal at the P2/J2 ECM connector.
Illustration 1 g03734119
Schematic diagram for the valve position sensors
Illustration 2 g03728447
Typical view of the pin locations on the 62-pin engine interface connector for the motorized valves
(29) EGR valve PWM signal
(30) EGR valve return
(33) EGR valve position