Bendix EC-60 UDS 170 / SPN 791 FMI 10 — DA Left WSS Loss of Sensor Signal

Code Details

Plain-English Meaning

The EC-60 had a valid signal from the drive axle left wheel speed sensor but lost it during vehicle operation. Unlike an open-circuit code detectable at rest, this records while the vehicle is moving — suggesting an intermittent connection or a tone ring that provides a signal at low speed but fails above a threshold.

The Bendix EC-60 table maps UDS code 170, blink code 04-04, J1587 003-10, and J1939 SPN 791 FMI 10 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

• ABS lamp on; code may be stored rather than continuously active
• Fault may be speed-dependent, appearing above a certain road speed
• Static harness checks may pass, failing only when flexed at speed
• ABS disabled at that corner while fault is active or stored
• May correlate with temperature, load, or specific operating conditions

Possible Causes

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

• Intermittent harness fault that opens when flexed at speed or under vibration
• Tone ring damage severe enough to cause complete signal loss above a threshold speed
• Connector backing out under vibration — terminal not fully locked in housing
• Sensor mounting loose, allowing physical movement away from the ring at speed
• Active sensor (if equipped) with an intermittent power supply failing at speed

First Checks

• Check all connector latches from sensor to EC-60 — a partially seated connector can pass a static pull test but separate under vibration.
• Inspect the harness routing for points where it contacts moving suspension or driveline components.
• Look for tone ring damage across its full circumference — extensive damage can cause intermittent complete loss at speed.
• If an active sensor is used, check the sensor supply voltage circuit for drops under load.
• Road test with Bendix ACOM live data to confirm whether the signal drops at a repeatable speed or condition.

Can I Keep Driving?

ABS is disabled at the affected wheel channel while this fault is active. Normal hydraulic or air base braking continues unaffected — the vehicle can brake, but anti-lock protection is not available at that corner. Drive conservatively to a service location. Do not operate in conditions where ABS intervention would be likely, such as slippery surfaces or loaded highway braking. Clear only after root-cause repair.

Related Lookup Pages

• FMI 10 explanation
• Bendix manufacturer hub
• ABS / ATC / ESP fault codes
• ABS Light symptom page
• Brake Warning Light symptom page
• Search this code