MID 087 - Chassis ECM
CID 3826 - Operator Seat Belt Action Alarm
FMI 04 - Voltage Below Normal
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| Illustration 1 | g02737818 |
Operator seat belt action alarm circuit | |
This diagnostic code indicates the Chassis ECM detects the operator seat belt action alarm relay voltage is below normal.
The following can cause this code:
- Relay signal circuit shorted to ground
- Relay failure
- ECM failure
Note: The following test procedure may create other diagnostic codes. Ignore these created codes and clear these created codes after the original diagnostic code has been corrected. Ensure diagnostic code CID 3826 FMI 04 is active before performing this procedure.
Note: Use a calibrated digital multimeter for this procedure.
Test Step 1. CHECK THE RELAY
- Turn on the disconnect switch and the keyswitch.
- Observe the diagnostic code status.
- Disconnect the relay from the harness.
- Check CID 3826 FMI 04 status.
Expected Result:
CID 3826 FMI 04 is active.
Results:
- OK - CID 3826 FMI 04 is active. Proceed to Test Step 2.
- NOT OK - CID 3826 FMI 04 is not active. The relay has failed.
Repair: Replace the relay
STOP
Test Step 2. CHECK THE GROUND
- Turn off the keyswitch and the disconnect switch.
- Disconnect the harness from the relay.
- Disconnect the harness connectors from the ECM.
- At the harness connector for the ECM, measure the resistance from the signal contact J1-54 (wire F488-BR) of the harness to all possible ground sources. Measure the resistance to all contacts of the harness connectors for the ECM.
Expected Result:
Each resistance is greater than 5000 ohms.
Results:
- OK - Each resistance is greater than 5000 ohms. Proceed to Test Step 3.
- NOT OK - A resistance is not correct. There is a short between signal contact J1-54 (wire F488-BR) and the circuit with the low resistance.
Repair: Repair or replace the harness.
STOP
Test Step 3. CHECK DIAGNOSTIC CODE
- Inspect the harness.
Clean and inspect the harness connector contacts for corrosion or damage.
Check the wire insulation for damage caused by heat, corrosion, or chafing.
- Perform a 45 N (10 lb) pull test on each circuit wire.
- Reconnect all harness connectors.
Verify that the connectors are fully seated and the clips are fastened.
- Check for intermittent problems. Using Cat® Electronic Technician (Cat ET), perform a wiggle test on the harness.
- Turn on the disconnect switch and the keyswitch.
- Operate the machine.
- Check CID 3826 FMI 04 status.
Expected Result:
CID 3826 FMI 04 is not active.
Results:
- OK - CID 3826 FMI 04 is not active.
Repair: The initial diagnostic code was probably caused by a poor connection at one of the connectors that was checked. Resume normal operation.
STOP
- NOT OK - CID 3826 FMI 04 is active. The ECM may have failed.
Repair: Exit this procedure and perform this procedure again. Contact your technical communicator. If the ECM requires replacement, see Testing and Adjusting, "Electronic Control Module (ECM) - Replace".
STOP