GLOW PLUG 9N0194 - Caterpillar

This procedure covers the following diagnostic codes:
Table 1
Diagnostic Trouble Codes for the Analog Throttle Position Sensor Circuit
J1939 Code Description Notes
91-3 Accelerator Pedal Position 1 : Voltage Above Normal The Electronic Control Module (ECM) detects that the setting for the upper diagnostic limit has been exceeded for at least 0.5 seconds.
The keyswitch has been ON for at least 2 seconds.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-3 Accelerator Pedal Position 2: Voltage Above Normal
91-4 Accelerator Pedal Position 1 : Voltage Below Normal The ECM detects that the setting for the lower diagnostic limit has been exceeded for at least 0.5 seconds.
The keyswitch has been ON for at least 2 seconds.
If equipped, the warning lamp will come on. The diagnostic code will be logged.
29-4 Accelerator Pedal Position 2: Voltage Below Normal If a fault occurs with the primary throttle with secondary throttle is installed, the secondary throttle will be used until the fault is repaired.If a fault occurs with the secondary throttle, the engine will use the primary throttle until the fault is repaired.If a functional throttle is not available, the following conditions will occur:
The engine will default to the limp home speed.
If the engine speed is higher than the limp home speed, the engine will decelerate to the limp home speed.
If the engine speed is lower than the limp home speed, the engine speed will remain at the current speed.
The engine will remain at this speed when the diagnostic code remains active.
All inputs from the faulty throttle are ignored by the ECM until the fault is repaired.
All inputs from the repaired throttle will be ignored by the ECM until the keyswitch has been cycled.The diagnostic codes above relate to an analog sensor. Use this procedure only if the analog sensor uses an output from a variable resistor.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 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 VDC 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.Use the electronic service tool to check the input status.Note: The identification letters for the terminals in the connectors may vary dependent on the manufacturer of the throttle pedal. Substitute the correct letters/numbers as required.
Illustration 1 g06013372
Schematic of the analog throttle position sensors
Illustration 2 g06036267
P1 and P2 harness connector pin locations for the analog throttle position sensors
(J1:23) Throttle 1 - 5 VDC supply
(J1:24) Throttle 1 -