938G Wheel Loader, 938G Series II Wheel Loader, IT38G Integrated Toolcarrier and IT38G Series II Integrated Toolcarrier Traction Control System Diagnostic Code List Caterpillar

Module Identifier (MID)

The electronic control module that has detected a failure is identified by the Module Identifier (MID). Each electronic control module on the machine has a unique MID. The MID for the ECM of the Traction Control System is 28.

Component Identifier (CID)

The Component Identifier (CID) is a code that describes the component that is believed to have caused the failure.

Failure Mode Identifier (FMI)

The codes for the Failure Mode Identifier (FMI) are defined by the Society of Automotive Engineers (SAE). The list of codes in Table 1 is used on AVSpare products.

Detailed FMI Explanations

FMI 00 - "Data Valid But Above Normal Operating Range." Every electronic control system sets a high limit for the expected operating range of the signal. The limit includes signals that are above the expected range. A sensor that is still working but sending a signal above the expected limit will cause an FMI 00 to be stored.

Some possible causes of FMI 00 are listed here:

• Signal above normal (High pressure or high temperature)

• Calibration is needed. FMI 13 is the preferred code.

For example, a certain PWM sensor is expected to generate a valid signal over 80 percent duty cycle. If the sensor generates a signal of 81 percent duty cycle, the sensor is still working but the signal is above the expected signal limits.

FMI 01 - "Data Valid But Below Normal Operating Range." Every electronic control system sets a low limit for the expected operating range of the signal. The limit includes signals that are under the expected range. A low engine oil pressure signal from a working sensor could produce this FMI. A sensor that is still working but sending a signal below the expected limit will cause an FMI 01 to be stored.

Some possible causes of FMI 01 are listed here:

• The signal is below normal. (The voltage, pressure, or temperature is low.)

• Timing is retarded.

For example, a certain PWM sensor is not expected to generate a PWM signal below 5 percent duty cycle even with zero air pressure. If the sensor generates a signal of 4 percent duty cycle with the engine shutdown, the sensor is still working but the signal is below the expected signal limits.

FMI 02 - "Data Erratic, Intermittent Or Incorrect." Signal data that is received from a component is valid. The data that is received from the component has become intermittent or erratic. Data can be correct sometimes and the data may be incorrect at other times. The communication that occurs between electronic controls also relates to this condition.

Some possible causes of FMI 02 are listed here:

• Loose connections in switches, harness, etc.

• Intermittent/erratic signal

• Programmed data has changed.

• Noisy signal

• The signal is out of range. FMI 00 or FMI 01 is the preferred code.

• A failed power or ground connection to the ECM

• Failed ECM

FMI 03 - "Voltage Above Normal Or Shorted High." The voltage that is received from a component is higher than the expected value that is identified by the CID. FMI 03 most often relates to a signal circuit.

Some possible components that can cause an FMI 03 are listed here:

• The sensor (switch)

• The harness

• The related electronic control

Some possible causes of an FMI 03 are listed here:

• A sensor output that is not related to the duty cycle is stuck at the maximum output of the sensor.

• A harness that has the sensor signal wire shorted to any voltage that is greater than the voltage of the sensor power supply.

• A sensor signal wire is open in the machine harness between the sensor and the control. When a sensor has been disconnected from an electronic control, the input circuit voltage is normally pulled up to a positive level.

• A sensor signal contact of a failed control that is internally shorted to a positive voltage source

• A failed control believes that a failure exists in a circuit that is working correctly. This is unlikely.

FMI 04 - "Voltage Below Normal Or Shorted Low." The voltage that is received from a component is lower than the expected value that is identified by the CID. FMI 04 most often relates to a signal circuit. FMI 04 is very similar to FMI 06. FMI 04 is sometimes used in the place of FMI 06.

Some possible causes of FMI 04 are listed here:

• The sensor

• The harness

• The related electronic control

Some possible cause of FMI 04 are listed here:

• A sensor output that is not related to the duty cycle is stuck at the minimum output of the sensor.

• The signal wire is shorted to ground in the harness.

• Electronic control has an internal short to ground on the connector contact of the signal input.

FMI 05 - Current Below Normal Or Open Circuit. The current of the monitored circuit is below normal. This usually results from an open circuit. FMI 05 is generally related to an output of a driver circuit.

Some possible causes of FMI 05 are listed here:

• Open circuit or poor harness connection

• High resistance circuit in a component (relay coil)

• Component in the open position (switch)

FMI 06 - "Current Above Normal Or Grounded Circuit." The current of the monitored circuit is above normal. This code is most commonly caused by a circuit that is shorted to ground. This is very similar to an FMI 04. FMI 06 is sometimes used in the place of FMI 04. FMI 06 is generally related to an output of a driver circuit.

Some possible causes of FMI 06 are listed here:

• A short to ground in the harness

• Low resistance (failure) in component coil (relay)

• Electronic control has an internal short to ground on the connector contact of signal input.

FMI 07 - "Mechanical System Not Responding Properly." A mechanical system does not respond in the expected manner when electrical commands are received from the electronic control.

For example, a sluggish solenoid valve causes a slow shift.

Some possible causes of FMI 07 are listed here:

• Improper response of a component

• Stuck component

• Component failure

• The engine is shutdown.

• Improper machine operation

FMI 08 - "Abnormal Frequency, Pulse Width Or Period. "The frequency of the signal or the width of a given signal pulse is not in the expected range. This code can also relate to a failed output circuit of a sensor or an open output circuit of a sensor.

Note: The period is the time in seconds for one cycle at a given frequency.

Some possible causes of FMI 08 are listed here:

• Intermittent connection of a signal circuit

• Misfire.

• Noisy signals that are caused by a nearby radio or magnetic field

FMI 09 - "Abnormal Update." This code relates to the communication that occurs between electronic controls via a data link. This code occurs when given control is unable to receive required information from another control via the data link. This code indicates that the communication link to the ECM has been lost for more than 5 seconds. The ECM is not responding.

Some possible causes of FMI 09 are listed here:

• Loose connections in the harness or switches

• Failed power or ground connections to the ECM

• No communication is available on the data link.

• Abnormal update because of a mismatch of software between electronic controls

• Failure of the electronic control

FMI 10 - "Abnormal Rate Of Change." The code is related to a signal that changes at a rate that is different from the expected rate. The RATE OF CHANGE is outside of the expected limit. This value is not outside of the expected maximum or minimum value.

For example, The ground speed increases too fast for normal operation. The output of the transmission speed sensor is sending an unreasonable signal.

FMI 11 - "Failure Mode Not Identifiable." This code is used when an electronic control determines that multiple Failure Mode Identifiers are responsible for a single failure.

Some possible causes of FMI 11 are listed here:

• Mechanical failure

• Machine damage to multiple circuits

FMI 12 - "Bad Device Or Component." The code is used for the situations that are listed here: The code is used when an electronic control does not receive an expected response from another electronic control via the data link. The code is also used when an electronic control receives an expected response from another electronic control but the response is not valid. This condition is also used when an electronic control is expected to send data periodically and the control does not send the data.

Some possible causes of FMI 12 are listed here:

• Control failure.

• Failure of the data link

• One or more controls with the incorrect software

FMI 13 - "Out Of Calibration." This code is used when the electrical signal of a given mechanical condition is not within the expected limits of the electronic control. The sensor needs calibration, adjustment or replacement.

The possible causes of FMI 13 are listed here:

• Calibration is required.

• Data out of range

Troubleshooting Procedures

Go to the procedure that corresponds to the CID and FMI that has been indicated. These procedures are used only for maintenance events (CID and FMI) that originate from the TCS. These procedures are used for CID's that have an MID of 28.

If the MID is not for the TCS, see the Module Identifier chart on the Electrical System Schematic for the machine that is being serviced. Once you have determined the electronic control modules that detected the event, refer to the Service Manual for that control for troubleshooting information. The Service Manual modules for each control are part of the machine Service Manual.

Diagnostic Codes