Q: What does Caterpillar fault code MID 087 CID 0373 FMI 05 mean?

MID 087 CID 0373 FMI 05 (Braking / Traction): Service Brakes Locked / Alarm Active Fix: LOGIC: Hydraulic Brake Accumulator Pressure Release Solenoid Open. ACTION: Check solenoid coil resistance on the brake valve block. Inspect brake manifold harness leads passing through the center swing turntable swivel manifold.

Q: What does Caterpillar fault code MID 087 CID 0420 FMI 05 mean?

MID 087 CID 0420 FMI 05 (Electrical / Steering): Secondary Steering Active / Alarm Fix: LOGIC: Secondary Steering Motor Relay Control Circuit Open. ACTION: Measure auxiliary DC electric pump relay coil resistance (~35Ω). Inspect relay harness pass-through connectors behind the cab hydraulic access panel.

Q: What does Caterpillar fault code SPN 168 FMI 1 mean?

SPN 168 FMI 1 (Electrical): Slow Crank / ECM Reset Fix: LOGIC: System Voltage Low (<9V). ACTION: Load test batteries. Check alternator S-terminal.

Q: What does Caterpillar fault code SPN 168 FMI 2 mean?

SPN 168 FMI 2: Lights flickering; Radio resetting; Random "ghost" codes across different systems; Hard starting. Fix: System Voltage Intermittent LOGIC: Battery voltage is "noisy" or dropping below 9V momentarily. ACTION: Perform a load test on batteries. Check the "Clean Machine Ground" (usually a small wire directly to the battery negative). Inspect alternator belt tension. FIX: Clean/tighten battery terminals; replace batteries or alternator.

Question 1

What does Caterpillar fault code 110-04 mean?

Accepted Answer

110-04: The ECM detects a "Short to Ground." Engine may enter an immediate severe derate or shutdown to prevent perceived overheating. Fix: ACTION: 1. Isolation Test: Unplug the sensor. If the code stays 110-04, the signal wire is rubbed through to the frame. 
2. Sensor Check: Measure resistance across sensor pins; "0" Ohms indicates an internal sensor short. 
3. Harness Search: Inspect the harness where it crosses over the valve cover or near the alternator.

Question 2

What does Caterpillar fault code 1250-9 mean?

Accepted Answer

1250-9 (Electrical): Remote Control Comm: Abnormal Update Fix: LOGIC: Loss of CAN heartbeat from RC module.

ACTION: Check CAT Data Link wiring and 120-ohm terminating resistors.

Question 3

What does Caterpillar fault code 2265-7 mean?

Accepted Answer

2265-7 (Hydraulic): Slow Hydraulic Cycle Times Fix: LOGIC: Hydraulic Pump #1 Outlet Pressure Sensor: Not Responding Properly.

ACTION: Swap pump #1 and pump #2 sensor connectors. If the fault moves, replace the pressure transducer.

Question 4

What does Caterpillar fault code 3413-5 mean?

Accepted Answer

3413-5 (Electrical): Fuel Lift Pump Failure Fix: LOGIC: Electric Fuel Priming Pump Current Below Normal.

ACTION: Measure resistance at the priming pump motor pins. If "Open Loop," the internal motor brushes are gone.

Question 5

What does Caterpillar fault code 3510-3 mean?

Accepted Answer

3510-3 (Electrical): Multiple Faults Fix: LOGIC: 5V Reference #2 Voltage High.

ACTION: Disconnect sensors on this rail one by one until the voltage stabilizes at 5.0V.

Question 6

What does Caterpillar fault code MID 036 CID 0168 FMI 01 mean?

Accepted Answer

MID 036 CID 0168 FMI 01 (Electrical): Multiple Sensor Faults / Monitor Blinks Fix: LOGIC: ECM Main Unswitched Battery Voltage Critically Low (<19V).

ACTION: Load test all 12V batteries in the 24V series-parallel bank under cranking conditions. Clean master disconnect ground studs and test battery charge output under full work light load.

Question 7

What does Caterpillar fault code MID 087 CID 0373 FMI 05 mean?

Accepted Answer

MID 087 CID 0373 FMI 05 (Braking / Traction): Service Brakes Locked / Alarm Active Fix: LOGIC: Hydraulic Brake Accumulator Pressure Release Solenoid Open.

ACTION: Check solenoid coil resistance on the brake valve block. Inspect brake manifold harness leads passing through the center swing turntable swivel manifold.

Question 8

What does Caterpillar fault code MID 087 CID 0420 FMI 05 mean?

Accepted Answer

MID 087 CID 0420 FMI 05 (Electrical / Steering): Secondary Steering Active / Alarm Fix: LOGIC: Secondary Steering Motor Relay Control Circuit Open.

ACTION: Measure auxiliary DC electric pump relay coil resistance (~35Ω). Inspect relay harness pass-through connectors behind the cab hydraulic access panel.

Question 9

What does Caterpillar fault code SPN 168 FMI 1 mean?

Accepted Answer

SPN 168 FMI 1 (Electrical): Slow Crank / ECM Reset Fix: LOGIC: System Voltage Low (<9V).

ACTION: Load test batteries. Check alternator S-terminal.

Question 10

What does Caterpillar fault code SPN 168 FMI 2 mean?

Accepted Answer

SPN 168 FMI 2: Lights flickering; Radio resetting; Random "ghost" codes across different systems; Hard starting. Fix: System Voltage Intermittent

LOGIC: Battery voltage is "noisy" or dropping below 9V momentarily.

ACTION: Perform a load test on batteries. Check the "Clean Machine Ground" (usually a small wire directly to the battery negative). Inspect alternator belt tension.

FIX: Clean/tighten battery terminals; replace batteries or alternator.

Caterpillar Fault Codes

Ready to take control of your fleet maintenance?

Other manufacturers

Code	System	Symptom	Full fix
110-04	—	The ECM detects a "Short to Ground." Engine may enter an immediate severe derate or shutdown to prevent perceived overheating.	View fix
1250-9	Electrical	Remote Control Comm: Abnormal Update	View fix
2265-7	Hydraulic	Slow Hydraulic Cycle Times	View fix
3413-5	Electrical	Fuel Lift Pump Failure	View fix
3510-3	Electrical	Multiple Faults	View fix
MID 036 CID 0168 FMI 01	Electrical	Multiple Sensor Faults / Monitor Blinks	View fix
MID 087 CID 0373 FMI 05	Braking / Traction	Service Brakes Locked / Alarm Active	View fix
MID 087 CID 0420 FMI 05	Electrical / Steering	Secondary Steering Active / Alarm	View fix
SPN 168 FMI 1	Electrical	Slow Crank / ECM Reset	View fix
SPN 168 FMI 2	—	Lights flickering; Radio resetting; Random "ghost" codes across different systems; Hard starting.	View fix