SAE J1939 SPN and FMI fault codes for chassis and suspension systems. Covers air suspension controllers, electronic steering, tire pressure monitoring, wheel speed sensors, and vehicle dynamic stability control on heavy-duty commercial vehicles.
Diagnostic Code SPN 7137 FMI 5: Meaning and Fix SPN 7137 FMI 5 indicates the Tire 25 pressure sensor circuit has an open circuit or current below normal. This fault commonly appears after a wheel-end repair or tire replacement where the sensor harness is accidentally pinched or left disconnected. Technicians often find this code when … Read more
Diagnostic Code SPN 7137 FMI 4: Meaning and Fix SPN 7137 FMI 4 indicates tire position 25 pressure sensor circuit voltage below normal threshold, typically under 0.5V. This fault commonly appears on commercial vehicles after tire replacement when technicians forget to reprogram new TPMS sensors or during cold weather startup when sensor batteries weaken. The … Read more
Diagnostic Code SPN 7137 FMI 31: Meaning and Fix SPN 7137 FMI 31 indicates an active pressure condition on tire position 25 in commercial vehicle tire pressure monitoring systems. This fault commonly appears during pre-trip inspections when drivers notice dashboard warnings after overnight temperature drops or following tire rotations where sensor programming hasn’t been updated. … Read more
Diagnostic Code SPN 7137 FMI 3: Meaning and Fix SPN 7137 FMI 3 indicates an abnormal high voltage in the Tire 25 pressure monitoring circuit, often after ECM replacements or wiring maintenance. This fault can result from a faulty sensor or improper calibration, leading to inaccurate tire pressure readings. In practice, technicians often detect this … Read more
Diagnostic Code SPN 7137 FMI 2: Meaning and Fix SPN 7137 FMI 2 indicates the Tire Pressure Monitoring System (TPMS) for Tire 25 is receiving erratic, intermittent, or incorrect data. This fault commonly appears after a wheel replacement or tire rotation without recalibrating the sensor ID in the ECM. Technicians frequently encounter this code when … Read more
Diagnostic Code SPN 7137 FMI 18: Meaning and Fix SPN 7137 FMI 18 indicates that the pressure data for tire 25 is valid but below the normal operating range, signifying a moderate severity issue. This fault often appears in heavy-duty trucks after prolonged highway driving, especially when tire pressure monitoring systems (TPMS) malfunction or lose … Read more
Diagnostic Code SPN 7137 FMI 14: Meaning and Fix SPN 7137 FMI 14 indicates the Tire Pressure Monitoring System (TPMS) for tire 25 has received a ‘special instructions’ command, often due to a failed automated learn cycle after tire rotation. Technicians frequently encounter this fault after replacing a wheel-end sensor or updating the ECU calibration … Read more
Diagnostic Code SPN 7137 FMI 13: Meaning and Fix SPN 7137 FMI 13 indicates tire 25 pressure sensor calibration drift beyond acceptable parameters in commercial vehicle tire pressure monitoring systems. This fault commonly emerges after tire replacement or TPMS sensor installation when technicians fail to perform proper calibration sequences. The ECM detects pressure readings outside … Read more
Diagnostic Code SPN 7137 FMI 11: Meaning and Fix SPN 7137 with FMI 11 indicates an undefined issue with the pressure of tire 25. This fault commonly appears in scenarios where vehicles experience sudden pressure drops after a tire replacement or following a terrain impact. In practice, technicians encounter this fault during routine maintenance checks, … Read more
Diagnostic Code SPN 7137 FMI 1: Meaning and Fix SPN 7137 FMI 1 indicates tire 25 pressure has dropped below the minimum operational threshold established by the manufacturer’s safety parameters. This fault commonly appears on commercial vehicles equipped with advanced tire pressure monitoring systems (TPMS) during pre-trip inspections or while operating under heavy loads. The … Read more