FAQ
TL;DR: Renault Magnum DXI code EMS MID 128 PPID 8 FMI 2 points toward piston cooling oil/boost-related checks; "Fuel supply at idle, approx. 3.5 to 3.7" bar is a useful yardstick. [Elektroda, Dagomir, post #16953343]
Why it matters: This FAQ helps DXI owners troubleshoot low power and decoding errors with simple, workshop-ready checks.
Quick Facts
- Code focus: Topic points to piston cooling oil/boost diagnostics for Magnum DXI. [Elektroda, Cobrat, post #16951234]
- Idle fuel supply pressure: Typical 3.5–3.7 bar on a working DXI. [Elektroda, Dagomir, post #16953343]
- Check boost under load; engine-brake valve sits right side near hot turbo outlet. [Elektroda, Dagomir, post #16953391]
- Always verify wiring to the boost sensor and measure real boost with a mechanical gauge. [Elektroda, Cobrat, post #16955339]
- Real-world case: 2011 Magnum 480 DXI EEV—error cleared, power loss persisted. [Elektroda, R2011480dxi, post #16953218]
What does EMS MID 128 PPID 8 FMI 2 mean on a Renault Magnum DXI?
In this thread, members tied that combination to piston-cooling oil pressure/boost-related checks. Start by confirming the sensor reading and real system behavior. "Piston cooling oil pressure" was explicitly mentioned as the signal to investigate. Verify with live data and a physical test before replacing parts. [Elektroda, Cobrat, post #16951234]
My 2011 Magnum 480 DXI EEV cleared the code but still lacks power—what’s next?
A cleared, inactive code does not guarantee restored performance. Continue diagnosis: log fuel supply pressure, log boost under load, and compare to expected values. Gather baseline data before further parts swaps. The case reported the error gone, yet power remained low, underscoring the need for on-road measurements. [Elektroda, R2011480dxi, post #16953218]
What fuel supply pressure should I see at idle on a DXI?
Expect approximately 3.5–3.7 bar at idle on a healthy DXI. Use a reliable gauge and confirm with the ECU live data. Keep hoses and filters clean to maintain this baseline. "Fuel supply at idle, approx. 3.5 to 3.7" is a practical target. [Elektroda, Dagomir, post #16953343]
Where is the engine-brake valve and how do I check it?
Stand behind the vehicle, right side of the engine, near the hot turbo outlet. Remove the exhaust pipe behind the valve, then command the brake via diagnostic software to observe movement. The boost check is best done under load to mirror real conditions. "The boost pressure is best checked under load." [Elektroda, Dagomir, post #16953391]
Diagnostics say low boost—what should I inspect first?
Measure actual boost with a mechanical gauge on a road test. If the sensor is new, focus on intercooler leaks, charge hoses, turbocharger health, and connections. Listen for whistling under load. Edge case: you can have no active DTCs and still have low power from leaks. [Elektroda, Dagomir, post #16953496]
Should I trust the scan tool alone for boost pressure?
No. Validate with a mechanical gauge (“clock”) and compare to the ECU reading. Discrepancies point to sensor, wiring, or scaling issues. This step saves time and prevents unnecessary parts replacement. Always pair live data with a physical measurement. [Elektroda, Cobrat, post #16955339]
Could wiring cause a false low-boost reading?
Yes. A damaged harness or connector at the boost sensor can mimic real low boost. Before chasing hardware faults, inspect and wiggle-test the sensor wiring, then recheck live data. Repair poor terminals and retest under load. [Elektroda, Cobrat, post #16955339]
I replaced the boost sensor and filters and still have no power—what now?
Confirm the turbo makes target boost under load with a gauge. If not, focus on the intercooler, charge piping, clamps, and turbocharger condition. Seemingly small leaks cause large losses at load. Only move on after sealing the charge-air path. [Elektroda, Dagomir, post #16953496]
How do I verify real boost pressure under load?
- Tee a calibrated mechanical gauge into the intake manifold pressure line.
- Perform a controlled road test on grade with logging enabled.
- Compare the gauge reading to ECU live data; investigate if they diverge. [Elektroda, Cobrat, post #16955339]
What readings did the thread starter observe for fuel pressure?
They reported about 5.5 bar at higher revs and under 4 bar at idle. Use this only as context, not a specification. Always compare to known-good values and repeat the measurement with your own equipment. [Elektroda, R2011480dxi, post #16953325]
How do I tell if the fault is the sensor or just the parameter reading?
Clarify whether the ECU flagged a sensor DTC or you only saw low boost in parameters. If it’s only parameters, verify with a mechanical gauge and inspect wiring. If it’s a sensor DTC, test voltage, ground, and signal before replacement. [Elektroda, Cobrat, post #16953523]
What if everything tests sealed but power is still down?
If the intercooler and piping are sealed, revisit turbocharger operation and installation. Check actuator movement, shaft play, and wastegate/VGT function. Only after confirming boost under load should you consider further fuel or exhaust restrictions. [Elektroda, R2011480dxi, post #16953517]
Do I need to check boost on a dyno, or is road testing enough?
Road testing under load is sufficient when performed safely and logged properly. It reflects real conditions better than a no-load rev test. Use the gauge and scan data together to validate results. [Elektroda, Dagomir, post #16953391]
Why might a shop say “we don’t know” after scanning?
A scan can show low boost but not its cause. Without verifying harness integrity and actual boost with a gauge, root-cause analysis stalls. Insist on physical tests alongside diagnostics to move forward. [Elektroda, R2011480dxi, post #16953368]
