Bendix EC-60 UDS 79 / SPN 1807 FMI 13 — SAS Calibration in Progress

Code Details

Plain-English Meaning

The SAS calibration procedure is currently in progress; this code clears automatically when calibration completes successfully. SAS calibration defines the straight-ahead reference; without a valid reference, the EC-60 cannot correctly interpret whether steering input represents a normal turn or a yaw instability event that needs correction.

The Bendix EC-60 table maps UDS code 79, blink code 21-02, J1587 089-13, and J1939 SPN 1807 FMI 13 to this ABS/ATC/ESP diagnostic entry. The Bendix source indicates an ABS and/or ATC/ESP warning lamp can be on for this entry. The EC-60 continuously monitors wheel speed sensor circuits, pressure modulation valve output drivers, supply voltage quality, J1939 network data from the engine and transmission controllers, and internal self-diagnostic routines. When any monitored value falls outside its acceptable range — or a circuit does not respond as the module expects — the EC-60 logs a diagnostic trouble code and may disable the affected ABS, ATC, or ESP function. Bendix ACOM Pro or a compatible diagnostic interface is the required tool for reading live sensor data, running actuator tests, performing calibrations, clearing latched codes, and adjusting EC-60 configuration parameters. Generic J1939 scan tools can read the SPN/FMI but cannot access EC-60-specific live data screens or configuration settings.

Common Symptoms

• ESP/stability lamp on; yaw-correction using steering angle data suspended
• ABS and ATC continue to operate normally
• Code commonly appears after SAS replacement, steering gear service, or front axle alignment
• Physical steering is unaffected — the fault is in the electronic reference, not the steering mechanism
• Code may clear automatically once the calibration procedure finishes

Possible Causes

Possible causes may include the items below. The list is not a parts diagnosis.

• SAS calibration not performed after sensor replacement, steering gear service, or alignment
• Front axle alignment changed after the last calibration — the steering neutral point has shifted
• SAS connector intermittently lost power during a drive cycle, resetting internal memory that contained the calibration reference
• Replacement SAS with a different zero-position trim requiring a new calibration
• ACOM calibration session interrupted before the reference capture step completed

First Checks

• Confirm front axle alignment is within specification before attempting calibration — calibrating on a misaligned axle creates a zero reference that will cause plausibility faults later.
• Connect Bendix ACOM and navigate to the SAS calibration function; follow the procedure with the steering wheel held at the confirmed straight-ahead position.
• After calibration completes successfully, clear stored codes and verify with ACOM live data that the SAS reads near zero angle with the steering wheel centered.
• Verify the SAS connector is fully seated and the supply voltage is stable — intermittent power can cause the sensor to lose its calibration reference.
• Test with a slow left and right lock-to-lock steering sweep to confirm the angle reading is smooth and returns to near zero at center.

Can I Keep Driving?

A stability sensor fault (yaw rate, steering angle, or lateral acceleration) disables ESP stability intervention while leaving ABS and ATC intact. The vehicle handles as it would without electronic stability control. Drive with that in mind — cornering, evasive maneuvers, and braking on slippery surfaces carry a higher risk. Stability sensor faults should be addressed before returning the vehicle to regular line-haul or severe-weather service.

Related Lookup Pages

• FMI 13 explanation
• Bendix manufacturer hub
• ABS / ATC / ESP fault codes
• ABS Light symptom page
• Brake Warning Light symptom page
• Search this code