450E Backhoe Loader Machine Electronic Control System Diagnostic Code List Caterpillar

Use the AVSpare Electronic Technician (Cat ET) in order to determine the diagnostic codes for the electronic control modules (ECM). After determining the diagnostic codes, refer to the corresponding test procedure for more information. Perform the procedure that corresponds to the Module Identifier (MID), the Component Identifier (CID) and the Failure Mode Identifier (FMI) of the diagnostic code.

Module Identifier (MID)

The module identifier (MID) identifies the electronic control module that detected the code. Each electronic control module on the machine has a unique MID. Use the following chart in order to match the MID for each diagnostic code to a specific electronic control module. The chart for the Module Identifier (MID) is located on the Electrical System Schematic for your machine. See the chart if the MID is not shown on the display of your machine. Refer to the service manual for that ECM. The service manual for each ECM is part of the Service Manual for the machine.

Component Identifier (CID)

The following table is a list of possible diagnostic codes for the machine ECM.

Failure Mode Identifier (FMI)

The codes for the Failure Mode Identifier are defined by the SAE standards. The following list contains a AVS version of definitions. The diagram that follows will help you understand the use of FMI with sensors.

Illustration 1	g00493694

Detailed FMI Explanation

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. A sensor that is still operating but sending a signal above the expected limit will cause an FMI 00 to be stored.

Some of the possible causes of an FMI00 are listed below.

• The signal is above normal.

• The signal is shorted to the +battery circuit.

• The sensor needs calibration.

The following is an example of a sensor that needs calibration. A PWM signal that is at a duty cycle of 80 percent is a valid signal. When the PWM signal has a duty cycle of 81 percent, the sensor is still working although 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 lower limit. The low signal could be the oil pressure signal. The sensor is still working but sending a signal below the expected limit will cause an FMI 01 to be stored.

Some of the possible causes of an FMI 01 are listed below.

• The signal is below the normal range.

• The timing is retarded.

The following is an example of a PWM sensor. This sensor is not expected to generate a PWM signal below a duty cycle of 5 percent with zero air pressure. The sensor generates a signal with a duty cycle of 4 percent when the engine is shut down. The sensor is still working but sending a signal below the expected limit will cause an FMI 01 to be stored.

FMI 02 "Data Erratic, Intermittent or Incorrect" - The signal from a component is present. The control that reads the diagnostic information cannot read the signal properly. The signal appears to be gone, unstable, or invalid. The data can be correct or incorrect intermittently. Also, this condition relates to communication between controls. The following is an example of communication between controls. When the monitoring system is looking for the engine speed from the engine ECM over the AVS data link.

• There is a failed connection.

• The signal is intermittent or erratic.

• The software has been changed.

• The signal is noisy.

• The signal is out of range.

FMI 03 "Voltage Above Normal or Shorted High" - The component or system voltage is higher than the limit. FMI 03 most often relates to a signal circuit.

Some of the components that could cause an FMI 03 are listed below.

• The sensor or the switch has failed.

• The harness is damaged.

• The electronic control module has failed.

Some of the possible causes of an FMI 03 are listed below.

• A sensor that has failed and the voltage output is high.

• Any wiring harness that has a sensor signal wire shorted to a high voltage. A high voltage is any voltage that is greater than the sensor supply voltage.

• A wiring harness that has an open circuit in the sensor signal wire will cause the control to pull up to the supply voltage.

• A control that has failed may also cause an FMI 03.

FMI 04 "The Voltage is Below Normal or the Voltage is Shorted Low" - The component or system voltage is lower than the limit. FMI 04 most often relates to a signal circuit.

Some of the components that could cause an FMI 04 are listed below.

• The sensor or the switch has failed.

• The harness is damaged.

• The electronic control has failed.

Some of the possible causes of an FMI 04 are listed below.

• A sensor that has failed and the voltage output is low.

• Any wiring harness that has a sensor signal wire shorted to ground.

• A failed ECM may also cause an FMI 04.

FMI 05 "Current Below Normal or Open Circuit" - The current through the component or the system is lower than the limit. FMI 05 is most often related to a driver circuit.

Some of the possible causes of an FMI 05 are listed below.

• There is an open circuit or a poor harness connection.

• There is an open relay.

• There is a switch in the open position.

FMI 06 "Current Above Normal or Grounded Circuit" - The current through the component or the system is higher than the limit. FMI 06 is most often related to a driver circuit. This fault is like FMI 04.

Some of the possible causes of an FMI 06 are listed below.

• There is a short to ground in the harness connection.

• There is a shorted relay.

• A failed control may also cause an FMI "06".

FMI 07 "Mechanical System Not Responding Properly" - The control detects a signal that is sent to a mechanical system and the response is not correct.

Some of the possible causes of an FMI 07 are listed below.

• The component responds improperly.

• The component is stuck in a position.

• The component has failed.

• The engine is shut down.

• The machine is being used improperly.

FMI 08 "Abnormal Frequency, Pulse Width or Period" - FMI 08 occurs when the signal is not in the expected range. FMI 08 can also relate to a faulty sensor.

Some of the possible causes of an FMI 08 are listed below.

• The harness connections are intermittent or poor.

• The engine misfired.

• The signal is noisy due to nearby interference.

• There are loose mechanical devices.

FMI 09 "Abnormal Update" - FMI 09 relates to communications on the data link. FMI 09 occurs when a control is not able to get information from another control.

Some of the possible causes of an FMI 09 are listed below.

• The control module is not communicating on the data link correctly.

• The rate of data transmission is abnormal.

• The data link has failed.

• There is a mismatch of software.

FMI 10 "Abnormal Rate of Change" - FMI 10 relates to a signal that changes too fast. The rate of change is outside of the expected limit.

FMI 11 "Failure Mode Not Identifiable" - The control identifies more than one FMI as being responsible for a single failure.

Some of the possible causes of an FMI 11 are listed below.

• There is a mechanical failure.

• There is damage to multiple circuits.

FMI 12 "Bad Device or Component" - The electronic control sends a signal and the electronic control expects a response. The control receives no response or the response is incorrect.

Some of the possible causes of an FMI 12 are listed below.

• There is a failure of the electronic control.

• There is a failure on the data link.

• There are one or more controls with mismatched software.

FMI 13 "Out of Calibration" - The electrical signal is not within limits for a specific mechanical condition.

Some of the possible causes of an FMI 13 are listed below.

• Calibration is required.

• The data is out of range.

FMI 14, 15, and 20 - These codes are not active.

FMI 16 "Parameter Not Available" - The control does not support the requested parameter.

FMI 17 "Module Not Responding" - The control does not respond to the request for data.

FMI 18 "Sensor Supply Failure" - The sensor power supply in the control has failed.

FMI 19 "Condition Not Met" - The conditions that are defined by the software were not met.