Caterpillar Cat ET Error Code CID 550 FMI 1

Caterpillar Generator Major Display

Model: Cat ET / EMCP 4.x | Code: 550-1

Applicable Systems
EMCP 4.2

Symptoms

CID 550 (Display Panel Communication): Data valid but below normal operating range. The Caterpillar Electronic Technician (Cat ET) displays this fault. Machine operation may be derated or shut down depending on severity.

Possible Causes

  • Sensor or actuator for Display Panel Communication failed or out of range
  • Wiring harness for CID 550 circuit open, shorted, or corroded
  • ECM parameter for Display Panel Communication out of calibration
  • Mechanical or hydraulic issue affecting the component

Troubleshooting Steps

  1. Step 1: Connect Cat ET and read active fault codes for CID 550
    Fault code 550-1 displayed with timestamp and component data
  2. Step 2: Inspect wiring harness and connector for CID 550 (Display Panel Communication)
    Wiring intact, connector clean and seated
  3. Step 3: Test Display Panel Communication sensor or actuator output
    Output within Caterpillar specification range
  4. Step 4: Check ECM for stored parameters and calibrate if needed
    Parameters within factory specification
  5. Step 5: Clear fault with Cat ET and verify no re-occurrence
    Fault cleared and does not return after test cycle

How to Reset

To reset: 1) Correct the underlying fault for CID 550. 2) Press FAULT RESET on the EMCP panel or clear via Cat ET. 3) Verify machine returns to normal operation. Caution: Do not reset without repairing the fault as the machine may operate in derated mode.

Frequently Asked Questions

  • Q: What does CID 550 mean on Caterpillar equipment?

    CID 550 refers to Display Panel Communication. It is a standard Caterpillar Component Identifier used in diagnostic systems.

  • Q: What does FMI 1 mean?

    FMI 1 indicates: Data valid but below normal operating range. FMI (Failure Mode Identifier) describes the type of failure detected.

Source: Caterpillar SAE J1939 CID/FMI Reference, wholefleet.ca/motorsymphdiesel.com

Category: Generator