Barometric Pressure Sensor Voltage Above Normal
What does VOLVO-MACK-MID128-PID108-FMI3 mean?
The VOLVO-MACK-MID128-PID108-FMI3 (Volvo/Mack D/MP Series) diesel fault code means: Barometric Pressure Sensor Voltage Above Normal. This is a minor severity code.
Common Symptoms
- Check Engine Light illuminated
- Affected gauge reads zero or maximum
- Possible engine derate
- Fault code active on scan tool
- May affect cold start performance
Probable Causes (Ranked by Likelihood)
- Failed BARO sensor element Very Likely
- Open, shorted, or chafed wiring to sensor Likely
- Corroded or backed-out connector pin Likely
- 5V reference supply out of spec Possible
- ECM input circuit fault Less Likely
Step-by-Step Diagnostic Procedure
Connect Volvo PTT or Mack Guided Diagnostics and monitor live data for BARO sensor — compare against known-good spec.
Unplug sensor connector and inspect for bent, corroded, or backed-out pins; check for moisture intrusion.
Measure 5V reference at signal return line (should be 4.9-5.1V key-on with sensor unplugged).
Measure sensor resistance across signal and return pins per Volvo/Mack service information.
Back-probe harness and wiggle-test while watching live data for intermittent faults.
If sensor tests in-spec, inspect harness between sensor and VECU for chafing.
Frequently Asked Questions
What does Volvo/Mack code MID128-PID108-FMI3 mean?
Volvo/Mack code MID128-PID108-FMI3 (Barometric Pressure Sensor Voltage Above Normal) 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 BARO sensor 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 MID128-PID108-FMI3?
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 MID128-PID108-FMI3?
Typical repair falls in the range $150-$600. 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.