Bendix EC-60 UDS 161 / SPN 791 FMI 2 — DA Left WSS Open or Shorted

The EC-60 found an open circuit or a short in the drive axle left wheel speed sensor circuit. Without a clean signal at that corner, ABS cannot control wheel braking there — ABS is suspended for that channel and ATC/ESP may be suspended as well.

Code Details

Structured details for Bendix EC-60 UDS 161 / SPN 791 FMI 2
Display codeBendix EC-60 UDS 161 / SPN 791 FMI 2
SPN791
FMI2
OEM codeBendix UDS 161, Bendix Blink 04-03, J1587 003-02
ManufacturerBendix
SystemABS / ATC / ESP
ComponentWheel speed sensor
Source addressUnknown or not applicable
Severityhigh
Review statusai source checked
Source confidencehigh
Last reviewed2026-03-04

Plain-English Meaning

The EC-60 found an open circuit or a short in the drive axle left wheel speed sensor circuit. Without a clean signal at that corner, ABS cannot control wheel braking there — ABS is suspended for that channel and ATC/ESP may be suspended as well.

The Bendix EC-60 table maps UDS code 161, blink code 04-03, J1587 003-02, and J1939 SPN 791 FMI 2 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 warning lamp on
  • ATC/ESP lamp on if stability functions are affected
  • ABS inactive at the affected wheel corner; normal braking is unaffected
  • Scan tool reads Bendix EC-60 UDS 161 / SPN 791 FMI 2 as active or stored
  • Traction control may be suspended on the affected axle

Possible Causes

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

  • Wiring open between drive axle left WSS connector and EC-60 harness
  • Short to ground or to battery voltage in the sensor circuit
  • Corroded, bent, or backed-out terminal in the sensor connector
  • Sensor coil internally open or shorted (passive sensors typically read 900–2000 Ω)
  • Harness chafed on axle housing, suspension bracket, or chassis ground point

First Checks

  • Inspect the drive axle left sensor connector for corrosion and bent pins before reaching for a meter.
  • With ignition off and connector unplugged, measure sensor coil resistance — out-of-range reading condemns the sensor.
  • Measure resistance from each sensor pin to chassis ground; any continuity indicates a short in the circuit.
  • Trace the harness from sensor to EC-60 looking for abrasion on axle housing and air-line bundles.
  • On the drive axle, inspect the axle housing seal and vent for oil seepage onto the sensor face; check the tone ring slots for mud or debris packed from road spray, which is more severe at rear drive axle positions.
  • After repair, clear with Bendix ACOM or equivalent and confirm the code does not return on a test drive.

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

Sources

  • Bendix EC-60 ABS/ATC/ESP Controllers Service Data SD-13-4869 Bendix Commercial Vehicle Systems, hosted in NHTSA Manufacturer Communications · oem · accessed 2026-05-05 · confidence high

    Source: Bendix Commercial Vehicle Systems, hosted in NHTSA Manufacturer Communications, Bendix EC-60 ABS/ATC/ESP Controllers Service Data SD-13-4869. This page paraphrases factual fields only and is not a substitute for the original document.

    Open source
  • Bendix EC-60 Advanced Controllers Service Data SD-13-4869 Bendix Commercial Vehicle Systems, hosted in NHTSA Manufacturer Communications · oem · accessed 2026-05-05 · confidence high

    Source: Bendix Commercial Vehicle Systems, hosted in NHTSA Manufacturer Communications, Bendix EC-60 Advanced Controllers Service Data SD-13-4869. This page paraphrases factual fields only and is not a substitute for the original document.

    Open source

FAQ

What does "open or shorted" mean for the drive axle left WSS?

The EC-60 tests the sensor circuit and found either no continuity (open) or an unwanted current path (short). Both conditions prevent the module from reading wheel speed at that corner.

Will the brakes still work with Bendix EC-60 UDS 161 / SPN 791 FMI 2 active?

Normal hydraulic or air braking continues. ABS — and possibly ATC/ESP — is suspended at that corner until the fault is repaired and cleared. Treat it as a safety-relevant condition.

Are drive axle WSS tone rings more susceptible to debris contamination than steer axle rings?

Yes. Drive axle tone rings are exposed to significantly more road spray, mud, and debris than steer axle rings because of the tire rotation direction and proximity to the road surface. Packed debris in tone ring slots distorts the signal enough to log WSS faults even with an electrically intact sensor and harness.