ABS Warning Lamp Circuit Open
The VOLVO-MACK-MID136-PID792-FMI5 (Volvo/Mack D/MP Series) diesel fault code means: ABS Warning Lamp Circuit Open. This is a minor severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- intermediate
- Estimated cost
- $200-$900
Down with a Volvo fault on the road?
Get connected with a verified mobile diesel mechanic near you. Verified diesel & reefer techs, launching on the freight corridor.
Find a mobile mechanic →A $30 car code reader can't do diesel. The HD7000 reads full-system codes and does parked DPF regen, idle/speed-limit, and service resets from the cab — on everything from a 6.7 Cummins/Power Stroke/Duramax pickup to Class-8 trucks (Detroit, Paccar, CAT, Volvo, Mack, International).
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Full-system 6/9/16-pin diesel scan tool for Cummins, Paccar, CAT, Detroit and more — plug-and-play, no subscription. A cheaper way to read heavy-duty codes a basic OBD2 scanner skips entirely.
Check Price on AmazonAffiliate link -- we earn a commission at no extra cost to you.
Common Symptoms
- ABS warning lamp illuminated
- Possible ATC (traction control) disabled
- ABS disabled during the affected wheel
- Check Engine Light may also set from multiplexing
Probable Causes (Ranked by Likelihood)
- Failed ABS warning lamp Likely
- Harness damage at wheel end or frame crossover Likely
- Tone ring contaminated with metal debris Possible
- Incorrect sensor air gap from loose mounting Possible
- ABS ECU fault Less Likely
Step-by-Step Diagnostic Procedure
Connect Volvo PTT or Mack Guided Diagnostics (ABS module) and verify MID136-PID792-FMI5 active; read wheel speed live data.
Inspect sensor mounting and air gap; clean tone ring of metallic debris.
Measure sensor resistance at the harness (spec typically 1000-2500 ohms).
Inspect harness routing for chafe at axle flex point and frame crossover.
After repair, road-test above 5 mph to verify fault clears and ABS lamp goes out.
Frequently Asked Questions
What does Volvo/Mack code MID136-PID792-FMI5 mean?
Volvo/Mack code MID136-PID792-FMI5 (ABS Warning Lamp Circuit Open) is a minor-severity diagnostic trouble code set on D11/MP7, D13/MP8, and D16/MP10 diesel engines in Volvo VNL/VNR and Mack Anthem/Pinnacle/Granite/Titan trucks. It indicates a fault in the ABS warning lamp system and should be read with Volvo Premium Tech Tool (PTT) or Mack Guided Diagnostics.
Can I drive a Volvo or Mack truck with code MID136-PID792-FMI5?
Limited short-term operation is usually possible, but the fault will illuminate the Check Engine Light and should be diagnosed promptly to avoid cascading aftertreatment or fueling faults.
How much does it cost to fix Volvo/Mack code MID136-PID792-FMI5?
Typical repair falls in the range $200-$900. Sensor/wiring repairs are at the low end; EGR cooler, NOx sensor set, DEF pump, injector, or head work runs at the high end. Volvo PTT or Mack Guided Diagnostics is normally required for calibration and parameter programming.
Sources
This page is built from documented references. Verify against your own service info before repair work.