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| Illustration 1 | g02639459 |
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| Illustration 2 | g02722153 |
Location of the Machine ECM | |
This diagnostic code is recorded when the Machine Electronic Control Module (ECM) does not receive expected information from the Machine Security System (MSS) key reader over the J1939 (CAN A) data link.
Note: The MSS must be installed in order for this diagnostic code to be logged.
Test Step 1. CHECK THE CAT ET SCREENS
- Check the active diagnostic screen and the logged diagnostic screen for a communication error between the Machine ECM and the key reader.
Expected Result:
The Caterpillar Electronic Technician (Cat ET) service tool reports CID 1960 FMI 09 as being active, or the diagnostic code has been logged.
Results:
- YES - The Cat ET service tool reports CID 1960 FMI 09 diagnostic code as being active, or the diagnostic code has been logged.
Repair: Examine the connections on the CAN A data link between the key reader and the Machine ECM. Ensure that all connections in the data link circuit are clean, tight and in good condition.
Proceed to Test Step 3.
- NO - The diagnostic code has not been logged or the diagnostic is not active.
Repair: The diagnostic code is not active at this time. Resume normal machine operation.
STOP
Test Step 2. CHECK FOR POWER TO THE KEY READER
- Disconnect the machine harness connector from the MSS key reader.
- Turn the key switch to the ON position. At the machine harness connector for the key reader, measure the voltage between contact "1" (wire 308-YL) and contact "2" (wire 200-BK). Measure the voltage between contact "1" (wire 308-YL) and frame ground.
Expected Result:
The voltage that is measured for each measurement is approximately 24 VDC.
Results:
- YES - The voltage that is measured for each measurement is approximately 24 VDC. The supply voltage is correct. Proceed to Test Step 3.
- NO - One of the voltage measurements is not correct. There is a problem in the wiring harness.
Repair: If the voltage measurement between contact "1" and frame ground is less than 24 VDC, then the supply wire 308-YL is either open or shorted in the machine harness. Check the wiring harness for signs of damage. Repair the machine harness or replace the machine harness.If the voltage measurement between contact "1" and contact "2" is less than 24 VDC and the frame ground measurement is OK, then the ground wire 200-BK is either open or shorted in the machine harness. Check the wiring harness. Repair the machine harness or replace the machine harness.
STOP
Test Step 3. CHECK THE TERMINATING RESISTORS AND THE DATA LINK CIRCUIT
- Reconnect the machine harness connector to the MSS key reader.
- Disconnect the "J2" machine harness connector from the ECM.
- Measure the resistance between the CAN A + contact "J2-67" (wire F711-YL) and the CAN A - contact "J2-68" (wire F712-GN) on the machine harness connector for the ECM.
Expected Result:
The resistance measurement is approximately 60 ± 3 Ohms.
Results:
- OK - The resistance is within the range. Proceed to Test Step 4.
- Not OK - The resistance is approximately 120 ± 6 Ohms. A terminating resistor is missing or damaged.
Repair: If a termination resistor is missing, install the missing resistor. If both resistors are present, measure the resistance between pin A and pin "B" of each termination resistor. The resistance should measure 120 ± 3 Ohms. Replace the termination resistor if the resistance is not 120 ± 3 Ohms.Verify that the repair eliminates the problem.
STOP
Test Step 4. CHECK THE STATUS OF THE DIAGNOSTIC CODE
- Inspect the contacts and clean the contacts of the harness connectors.
- Reconnect all harness connectors.
- Turn the disconnect switch and the key start switch to the ON position.
- Clear all inactive diagnostic codes.
- Operate the machine.
- Determine if the CID 1960 FMI 09 is active.
Expected Result:
The CID 1960 FMI 09 is active.
Results:
- YES - The CID 1960 FMI 09 is active. The problem has not been corrected. The ECM may have failed.
Repair: Check the data link circuit again. Use the Caterpillar Electronic Technician (Cat ET) service tool in order to perform a wiggle test on the machine wiring harness. The wiggle test can detect momentary or intermittent shorts or opens in the machine wiring harness. If the cause of the problem cannot be found, the ECM or the MSS key reader module may be faulty.If the cause of the problem is not found, the ECM may have failed. Prior to replacing an ECM, always contact the technical communicator at your dealership for possible consultation with Caterpillar. This consultation may greatly reduce repair time. If the cause of the diagnostic code is not found and the ECM must be replaced, refer to the Troubleshooting, "Electronic Control Module (ECM) - Replace" Section of this manual for details.
STOP
- NO - The CID 1960 FMI 09 diagnostic code is not active. The problem does not exist at this time.
Repair: The initial diagnostic code may have been caused by a poor electrical connection that was corrected when a harness connector was disconnected and reconnected. Resume normal machine operation.
STOP