The MP8 is the Volvo D13's sibling under the bulldog hood — same architecture, same MID/PID format, Mack-specific calibrations and the mDRIVE transmission alongside. This page covers the Mack-specific picture; the format explainer lives on the Volvo D13 page.
How Mack MP8 fault codes work
Mack uses MID/PID/PPID/SID + FMI identically to Volvo (see the D13 page for the full format lesson). MP7 and MP8 share the code list; MP8HE adds efficiency-package codes noted below.
Most-searched Mack MP8 codes
These are the codes technicians look up most. Every row links to a full code page with symptoms, ranked causes and step-by-step diagnostics.
| Code | Meaning | Severity | Common fix |
|---|---|---|---|
| MID 128 PID 102 FMI 4 | Boost pressure low | Medium | Sensor/harness |
| MID 128 PPID 270 FMI 4 | EGR valve fault | High | EGR service |
| MID 128 PID 409 FMI 0 | SCR efficiency low | Critical — derate chain | PTT guided SCR diag |
| MID 128 PID 407 FMI 4 | NOx sensor inlet low | High | Sensor/harness |
| MID 130 (mDRIVE) SID 24 FMI 7 | mDRIVE clutch actuator | High | Clutch calibration in PTT |
| MID 128 PID 27 FMI 3 (MP8HE) | EGR flow high (HE package) | Medium | HE-specific calibration check |
Tools that read and clear Mack MP8 codes
The same PTT + Vocom II setup that covers Volvo covers Mack — one license, both brands. mDRIVE clutch work specifically wants PTT's guided calibration; it's the procedure that separates shops that can service Macks from shops that can't.
Frequently Asked Questions
Are MP7 and MP8 fault codes the same?
Yes — same engine architecture and ECU family. This list serves both; the MP8HE efficiency package adds a few codes around its unique EGR routing.
Can I use Volvo documentation for a Mack engine?
Largely yes for the engine — shared architecture means shared service logic. Chassis and mDRIVE documentation is Mack-specific.