67232-94300 Suzuki Bush

Diagnostic Codes
Diagnostic trouble codes are generated by the Electronic Control Module (ECM) to alert the operator that a problem has been detected. The problem can be in the electronic system or in the mechanical system. Diagnostic trouble codes are used by the service technician to help in the identification of the nature of the problem. Cat Electronic Technician (ET) is a software program that can be used by the service technician to view the diagnostic code information. Refer to Troubleshooting, "Electronic Service Tools" for detailed information that is related to the functionality of Cat ET.The *Controller Area Network (CAN) data link is used by the ECM to communicate with controllers, display modules, and electronic service tools. The ECM transmits information and the ECM receives information over the CAN data link. The communications protocol and the diagnostic messages over the CAN data link conform to the SAE J1939 industrial standards.Note: The SAE J1939 industrial standards refer to the control module for the engine as the Electronic Control Unit (ECU). This manual refers to this control module as the Electronic Control Module (ECM).Communications with electronic service tools aid the technician in diagnostics and troubleshooting for the engine and the engine subsystems. When a problem with the engine is detected by the ECM, the ECM communicates information about the problem over the CAN data link. The problem may be physically detected by one of the input or output circuits by the ECM. A problem can also be communicated via the data link to the ECM. The ECM transmits this information over the data link in a form of a diagnostic trouble code and code description.The diagnostic trouble code has a format of a two-element code. The following terms describe the elements of the code:Suspect Parameter Number (SPN) - The SPN is a code which is assigned to each component. The SPN identifies the origin of the problem.Failure Mode Identifier (FMI) - The FMI is used with the SPN to provide more information that relates to the problem. The FMI may indicate that a problem with an electronic circuit or an electronic component has been detected. The FMI may also indicate that an abnormal operating condition has been detected.The codes are displayed in the form “SPN-FMI”. The ECM also attaches a text description to the message that is transmitted over the data link. This text description is used to describe the SPN-FMI code.The failure mode identifiers can be divided into two categories:
Codes that indicate that a problem with an electronic circuit or an electronic component has been detected
Codes that indicate that an engine event or a system event has been detectedThe failure mode of the fault is determined by evaluating the electronic signal from the suspect circuit. Typically, the first category of code is generated when the signal for the circuit is outside the range of the sensor. The second category of code is an engine event. An engine event indicates that the sensor signal is OK, but the signal is outside the normal operating range of the engine parameter. Illustration 1 is an example that represents the evaluation of a sensor signal by the ECM.
Illustration 1 g01950177
Example of the typical electrical signal of a sensor
(1) This area represents the normal operating range of the engine parameter.
(2) In these areas, the engine is operating in an unsafe operating range of the monitored parameter. A diagnostic code that indicates an engine event will be generated for the monitored parameter. The sensor circuit does not have an electronic problem. Refer to Systems Operation, "Engine Monitoring System" for additional information that is related to engine events.
(3) In these areas, the signal from the sensor is outside of the operating range of the sensor. The sensor circuit has an electronic problem. A diagnostic trouble code that indicates that a problem with the circuit has been detected will be generated.When you troubleshoot a diagnostic trouble code, be sure to evaluate the problem from the viewpoint of an interpretation of the electrical signal. Refer to the above illustration for an evaluation of the sensor signal.Cross-Reference Information for Diagnostic Codes
Table 1 is a list of the diagnostic codes for this engine. The diagnostic codes are cross-referenced with the appropriate procedure that can be used to troubleshoot the code.
Table 1
Cross-Reference from Diagnostic Trouble Codes to Functional Test or Procedure
J1939 Code and Description CDL Code and Description Troubleshooting Procedure
28-3
Accelerator Pedal Position #3 : Voltage Above Normal 774-3
Secondary Throttle Position Sensor : Voltage Above Normal Troubleshooting, "Speed Control - Test"
28-4
Accelerator Pedal Position #3 : Voltage Below Normal 774-4
Secondary Throttle Position Sensor : Voltage Below Normal Troubleshooting, "Speed Control - Test"
29-3
Accelerator Pedal Position #2 : Voltage Above Normal 774-3
Secondary Throttle Position Sensor : Voltage Above Normal Troubleshooting, "Speed Control - Test"
29-4
Accelerator Pedal Position #2 : Voltage Below Normal 774-4
Secondary Throttle Position Sensor : Voltage Below Normal Troubleshooting, "Speed Control - Test"
29-8
Accelerator Pedal Position #2 : Abnormal Frequency, Pulse Width, or Period 774-8
Secondary Throttle Position Sensor : Abnormal Frequency, Pulse Width, or Period Troubleshooting, "Speed Control - Test"
52-3
Engine Intercooler Temperature : Voltage Above Normal 279-3
Aftercooler Coolant Temperature Sensor (Front) : Voltage Above Normal Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
52-4
Engine Intercooler Temperature : Voltage Below Normal 279-4
Aftercooler Coolant Temperature Sensor (Front) : Voltage Below Normal Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
91-3
Accelerator Pedal Position #1 : Voltage Above Normal 91-3
Accelerator Pedal Position #1 : Voltage Above Normal Troubleshooting, "Speed Control - Test"
91-4
Accelerator Pedal Position #1 : Voltage Below Normal 91-4
Accelerator Pedal Position #1 : Voltage Below Normal Troubleshooting, "Speed Control - Test"
91-8
Accelerator Pedal Position #1 : Abnormal Frequency, Pulse Width, or Period 91-8
Accelerator Pedal Position #1 : Abnormal Frequency, Pulse Width, or Period Troubleshooting, "Speed Control - Test"
95-2
Engine Fuel Filter Differential Pressure : Erratic, Intermittent, or Incorrect 95-2
Engine Fuel Filter Differential Pressure : Erratic, Intermittent, or Incorrect The filtered fuel pressure is greater than the unfiltered fuel pressure. Ensure that the sensor connectors are connected to the correct sensors. If an electrical problem with a sensor is suspected, refer to Troubleshooting, "Sensor Signal (Analog, Active)