Challenger 35, Challenger 45 and Challenger 55 Agricultural Tractors Electronic Systems Caterpillar

The purpose of the troubleshooting procedure is to determine which component has failed. Troubleshooting procedures progress from most likely points of failure to least likely. The procedures have the following prioritization:

• Component is bad.

• Wiring or connectors are bad.

• Electronic module is bad.

Each procedure assumes the following data:

• No previous troubleshooting, or tampering has been performed on system.

• No other fault codes are reporting.

• The fault code is currently being shown.

• Modules are working sufficiently enough to report the fault code in the first place. Are the indicators flashing on the RHC and CCM? Is the EMC status lamp on or flashing?

• The diagnostics will work correctly to identify the fault. Create a fault by unplugging a sender for a particular module. Does the appropriate fault code appear?

Assume for repair:

• Shop conditions are preferable to field conditions for troubleshooting. Additional time will be required to troubleshoot in the field.

• The batteries are fully charged and the charging system is operating properly.

• Extension connectors, connector probes, digital metering and power supplies are available.

• Caterpillar Electronic Technician (ET) is available and the technician is trained on the operation of CAT ET. See Testing And Adjusting, "Service Tools".

• Spare sensors are available: engine oil pressure sensor, engine coolant temperature sensor, transmission oil temperature sensor, aftercooler temperature sensor and draft pin sensor. Components that cannot be tested with a meter should be on hand for troubleshooting.

• Spare modules available: EMC, RHC and CCM.

Initial Troubleshooting Procedures

1. Check for current fault codes using Mode 1, Operator Calibrations. List the codes if multiples exist. If no faults are present and the is still a problem, see "Troubleshooting Procedures Without Fault Codes".

2. Enter Mode 2, View/Clear Stored Fault Codes. Record all stored codes, the hour they occurred and the number of times they repeated.

3. After the faults have been recorded, clear the faults from memory and operate the machine again.

4. Only troubleshoot current fault codes. Earlier faults may be the cause of subsequent faults. The first fault to occur may have something to do with faults that occur later. Use the Caterpillar Electronic Technician (CAT ET) tool whenever possible.

5. Have other technicians or owner(s)/ operators performed repairs prior to your troubleshooting? Get all of the facts about what has been done before attempting to diagnose faults in the electrical system. Make sure all prior work has been performed with authorized replacement parts and proper repair/installation procedures. Be wary of any prior temporary repairs, which could potentially be causing fault codes to report. Fault code diagnostic procedures do not consider conditions where improper components are used, nor conditions where improper previous repairs have been performed.

6. Each troubleshooting procedure approaches the diagnostic task as if there were only one fault code and the condition has just occurred, or is currently flashing on the EMC. Conditions with multiple faults must be diagnosed by the repair technician's judgment using information in all of the involved troubleshooting procedures. This will involve studying the troubleshooting procedures for all of the reported fault codes, prior to performing any diagnostic task. Whenever dealing with multiple fault codes, do not assume priority should be given to the lowest, or highest fault code number. If all codes occurring have the same engine hour time of occurrence, priority should be given to circuitry problems that affect, or influence all of the circuits involved in the reported fault codes. For instance, if a power supply, or signal ground fault code is reported, give it priority over fault codes for individual components.

7. During the course of diagnosing the system, it is important to note whenever using CAT ET to observe fault codes, the user must not forget many codes are key reset only. In other words, you can correct the problem, but the fault code will continue to report until the key start switch is turned OFF and then back ON.

8. Also, CAT ET does not continuously scan the system for fault codes, it only reports with a list what the on board computers are currently reporting when a request is made. Fault codes can be cleared or even new ones occur without being shown on the tool. For updates, the user must scan the system after each fix or attempt to repair the system.

9. It is important to follow each fault code diagnostic procedure step by step, since skipping steps may lead to erroneous results, lengthier troubleshooting time, or replacement of functional components. The proper sequence for troubleshooting the system is to begin with components such as switches, potentiometers and sensors. Progress to the harness and connectors. Finally resolve the problem to the modules. If a module must be replaced, use care in handling the new modules, verify hardware and software revision levels for compatibility and remember to enter Mode 12, Machine Features/Configuration at the EMC, to program the proper setup and to save the setup.

10. In dealing with complex fault codes where multiple conditions must occur in order for a fault code to report, a repair must be followed by testing to the required conditions. Several faults, such as engine coolant temperature, take up to 20 minutes before reporting a fault condition. Others require the machine to be in motion, or in gear, or engine running etc., before reporting a fault code. Before verifying a fix, make sure all fault conditions are met first.

Troubleshooting Procedures With Fault Codes

• Go to the procedure which corresponds to the fault code that is showing on the MPM display of the EMC.

• To troubleshoot using connectors C001 and C002, unbolt the CCM inside the cab, lift the CCM up and disconnect the C001 and C002 connectors.

Troubleshooting Procedures Without Fault Codes

• To troubleshoot using connectors C001 and C002, unbolt the CCM inside the cab, lift the CCM up and disconnect the C001 and C002 connectors.

• If no faults codes are present or multiple circuits are not power up or some items do not function, the probable cause is loss of power. The loss of power could be caused by poor connections, failed fuses or possible open circuit due to failed wiring or failed components.

• Always check the RD-2 power wire from the main distribution panel to the battery box for possible damage. Also check the connector (RD-2 to RD-4) located in the battery box for poor or loose connection. Repair the faulty components or replace the faulty components.