System Operation Description:
Use this procedure to troubleshoot the electrical system if a problem is suspected with the Electronic Control Module (ECM) and/or if any one of the diagnostic codes in Table 1 is active or easily repeated.
Note: Also, use this procedure if the integrity of the configuration parameters or the engine lifetime totals is questionable.
| Diagnostic Codes Table | ||
| Code and Description | Conditions which Generate this Code | System Response |
| 252-11 Calibration Module : Other Failure Mode | The flash file is for a different engine family or for a different engine application. | The engine will not start. Clearing this diagnostic code requires factory passwords. The personality module code must be reset to zero. |
| 252-12 Calibration Module : Failure | ||
| 253-2 Personality Module : Erratic, Intermittent, or Incorrect | The flash file is for a different engine family or for a different engine application. There may be a problem with the configuration parameters. |
The engine will not start. Clearing this diagnostic code requires factory passwords. The personality module code must be reset to zero. |
The ECM is the computer that controls the engine. The personality module chip contains the ECM software that controls the operation of the computer (ECM). The flash file is a software file that is downloaded into ECM memory (personality module chip) in order to program the ECM for a specific engine application. Flash programming is the preferred method for updating the software. This procedure eliminates the need to physically remove the personality module from the ECM. This procedure also decreases the risk of moisture entry into the ECM due to improper seal installation.
Test Step 1. Inspect the Electrical Connectors and the Wiring
- Remove electrical power from the ECM.
Illustration 1 g01139425
ECM
(1) J1/P1 connectors
(2) J2/P2 connectors
- Thoroughly inspect connectors (1) and (2). Also inspect the battery connections. Refer to Troubleshooting, “Electrical Connectors – Inspect” for details.
- Perform a 45 N (10 lb) pull test on each of the wires that are associated with the circuit for the air shutoff system.
- Check the allen head screw on the ECM connectors for the proper torque. Refer to Troubleshooting, “Electrical Connectors – Inspect” for the correct torque value.
- Check the harnesses and the wiring for abrasion and for pinch points.
Expected Result:
All connectors, pins and sockets are completely coupled and/or inserted and the harnesses and wiring are free of corrosion, of abrasion, and of pinch points.
Results:
- OK – The harnesses and the connectors are OK. Proceed to Test Step 2.
- Not OK – The wiring and/or a connector are not OK.Repair: Repair the wiring and/or the connectors. Replace parts, if necessary. Ensure that all of the seals are properly in place and ensure that the connectors are completely coupled. Verify that the repair eliminates the problem.
STOP
Test Step 2. Check for Diagnostic Codes
- Restore electrical power to the ECM.
- Use Caterpillar Electronic Technician (ET) to check for active diagnostic codes. Observe the “Active Diagnostic” screen on Cat ET. Wait at least 30 seconds so that any codes may become active. Look for these codes:
- 252-11
- 252-12
- 253-2
- Verify the integrity of engine’s configuration parameters.
Expected Result:
None of the above codes are active. The integrity of the configuration parameters is intact.
Results:
- OK – None of the above codes are active. The integrity of the configuration parameters is intact.Repair: If an intermittent condition is suspected, refer to Troubleshooting, “Electrical Connectors – Inspect”.
STOP
- Not OK – A 252-11 or 252-12 diagnostic code is active. Proceed to Test Step 3.
- Not OK – A 253-2 diagnostic code is active. Proceed to Test Step 4.
Test Step 3. Check For Current Software
- Restore the electrical power to the ECM.
- Use Cat ET to verify that the correct software is installed. Refer to Service Information System (SIS Web) in order to check for the latest release of the software for the serial number of your engine.
Expected Result:
The correct software is installed in the ECM.
Results:
- OK – The correct software is installed in the ECM. Proceed to Test Step 4.
- Not OK – The correct software is not installed in the ECM.Repair: Install the correct personality module into the ECM or flash program the correct software into the ECM. Refer to Troubleshooting, “ECM – Replace” or refer to Troubleshooting, “ECM Software – Install”. Verify that the repair eliminates the problem.
STOP
Test Step 4. Review the Parameters and Data
- Restore the electrical power to the ECM.
- Use Cat ET to review the system configuration parameters and the engine lifetime totals.
Expected Result:
The parameters and totals are correct.
Results:
- OK – The parameters and totals are correct.Repair: The engine will not start until the 253-2 diagnostic code is cleared.Use Cat ET to obtain the factory passwords that are needed to reset the personality module code to zero. Refer to Troubleshooting, “Factory Passwords”. Clear the 253-2 diagnostic code.If an intermittent condition is suspected, refer to Troubleshooting, “Electrical Connectors – Inspect”.
STOP
- Not OK – The parameters and/or the totals are incorrect.Repair: Program the suspect parameters and/or the engine lifetime totals. Refer to Troubleshooting, “Configuration Parameters”.If the ECM will not accept the programming, replace the ECM. Refer to Troubleshooting, “ECM – Replace”. Verify that the repair eliminates the problem.
STOP