Mercedes-Benz P0106

MAP sensor performance on Mercedes — OM651 diesel boost sensor and M271/M274 petrol intake sensors both fail with mileage.

Mercedes-Benz P0106 — MAP sensor performance on Mercedes — OM651 diesel boost sensor and M271/M274 petrol intake sensors both fail with mileage. Typical UK independent garage cost: £140–£480.

What actually causes P0106 on a Mercedes-Benz

OM651 diesel boost sensor (mounted in the charge pipe) suffers contamination from EGR soot blowing back through a leaking EGR cooler — clean it, or replace if signal is permanently drifted. M271 Kompressor petrol has a long history of intake manifold flap problems that present as P0106. M274 modern turbo petrol fails the sensor by 80k miles.

Mercedes-Benz engines that log P0106

• OM651 2.1 diesel (C/E/GLK)
• M271 1.8 Kompressor petrol
• M274 2.0 turbo petrol (C/E/GLA/CLA)
• M276 3.0 V6 biturbo

How we diagnose P0106 on a Mercedes-Benz

1. Xentry — read MAP/boost sensor live data vs commanded
2. On OM651, pressure-test cooling for EGR cooler leak (root cause of sensor fouling)
3. On M271, check intake manifold flap actuator
4. Replace MAP sensor if cleaning doesn't restore signal
5. Test-drive and confirm boost tracks correctly

The common misdiagnosis to avoid

Don't approve a Mercedes-quoted 'turbo and intake decontamination' (£900+) on OM651 — clean the sensor, fix the EGR cooler leak that contaminated it, and the code's gone for £200–£300.

Mercedes-Benz P0106 repair cost in the UK

Expect £140–£480 including parts and labour at an independent garage. Main-dealer quotes on Mercedes-Benz are usually higher for the same job, and the spread exists because the cheap cause and the expensive cause throw the same code — pay for the diagnosis before you pay for parts.

Bob's workshop tip

If you've got an OM651 with both P0106 and slowly disappearing coolant, the EGR cooler is leaking — fix that first, replace the contaminated sensor afterwards. Doing it in the wrong order means a new sensor fouls within weeks.

Codes usually seen alongside P0106 on Mercedes-Benz

• P0299
• P2002
• P0401

Symptoms drivers report with P0106

• Sudden loss of power on a motorway slip road — car drops into limp mode at exactly the point you plant the throttle
• Full power returns after a key-off / key-on cycle, then disappears again 10–20 miles later
• Whistling, hissing or a chuff-chuff noise from the engine bay under acceleration
• Slight oil mist around intercooler pipework or a stain on the underside of the bonnet
• MPG drops 4–8 mpg within a tankful, sometimes with faint black smoke on hard acceleration
• Sometimes paired with P0299 (underboost), P0234 (overboost), or P0401 (EGR flow)

Repairs that clear P0106

• Clean or replace MAP sensor
• Smoke-test intake and boost pipes
• Check EGR isn't stuck open

For the generic, all-makes explanation of this code — meaning, every known cause and UK cost bands — see our P0106 guide.