0432152 JOHNSON CARB ASSY., Upper

Table 1
J1939 Code and Description Comments
28-3
Accelerator Pedal Position 3 : Voltage Above Normal The Electronic Control Module (ECM) has detected that the analog "0–5 Volt" desired speed signal has exceeded the 4.5 volt trip point.
The setting for the upper diagnostic limit has been exceeded for .6 seconds.
The code is logged.
28-4
Accelerator Pedal Position 3 : Voltage Below Normal The ECM has detected that the analog "0–5 Volt" desired speed signal is below the .5 volt trip point.
The setting for the lower diagnostic limit has been exceeded for .6 seconds.
The code is logged.
29-3
Accelerator Pedal Position 2 : Voltage Above Normal The ECM has detected that the "PWM" desired speed signal is above the 95% diagnostic limit.
The alarm output is activated.
The code is logged.
29-4
Accelerator Pedal Position 2 : Voltage Below Normal The ECM has detected that the "PWM" desired speed signal is below the 5% diagnostic limit.
The alarm output is activated
The code is logged.
29-8
Accelerator Pedal Position 2 : Abnormal Frequency, Pulse Width, or Period The ECM has detected an erratic signal for the "PWM" desired speed signal.
The alarm output is activated.
The code is logged.
91-3
Accelerator Pedal Position 1 : Voltage Above Normal The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
91-4
Accelerator Pedal Position 1 : Voltage Below Normal The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
91-8
Accelerator Pedal Position 1 : Abnormal Frequency, Pulse Width, or Period The PWM signal from the sensor to the ECM is not correct.
The code is logged.
974-5
Remote Accelerator Pedal Position : Current Below Normal The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged.
974-6
Remote Accelerator Pedal Position : Current Above Normal The ECM detects signal voltage that is not in the acceptable range.
The ECM flags the throttle position as invalid data and a default value is used. The engine speed is limited to high idle.
The code is logged. For this troubleshooting procedure, the "Desired Speed Input" configuration parameter can be set to "4 - 20 mA" input, "PWM" input, or "0-5 Volt"input.The engine ECM will only monitor the status of the input signal for the PWM and 0-5 Volt desired speed inputs.The engine ECM does not supply the power and ground for the PWM or 0-5 Volt speed control circuits.If an external speed control source device is used, refer to that devices troubleshooting procedure.If using the CAN desired speed input, refer to Troubleshooting, "Data Link - Test".The value of the current, frequency, or voltage corresponds to a range of desired engine speeds between minimum high idle and maximum high idle. The "Minimum Engine High Idle Speed" and the "Maximum Engine High Idle Speed" are set with the "Service/Configuration" screen of Cat ET. For more information, refer to Troubleshooting, "Configuration Parameters".When the idle/rated speed switch is in the Idle position, a current value of 4.0 mA, 5% duty cycle, or .5 Volts corresponds to the programmed "Minimum Engine High Idle Speed". A current value of 20.0 mA, 95% duty cycle, or 4.5 Volts corresponds to "Maximum Engine High Idle Speed". Desired speed input values within this range will vary the desired engine speed in a linear fashion between. The range will vary between "Minimum Engine High Idle Speed" and "Maximum Engine High Idle Speed".The most likely causes of a diagnostic code for this circuit are a poor connection or a problem in a wiring harness. The next likely cause is a problem with a component. The least likely cause is a problem with the ECM.
Illustration 1 g06205151
Table 2
Troubleshooting Test Steps Values Results
1. Inspect the Electrical Connectors and the Wiring
A. Turn the main disconnect switch to the OFF position.
B. Thoroughly inspect the connectors. Refer to Troubleshooting, Electrical Connectors - Inspect for additional information.
C. Perform a 45 N m (33 lb ft) pull test on the connector wires.
D. Check the harness for abrasions and pinch points.
Connectors and Wiring
Result: The connectors and wiring appear to be OK.
Proceed to Test Step 2.
Result: There is a problem with the connectors and/or wiring.
Repair: Repair