Air intakeGeneric OBD-II codeUrgency: Monitor

P0507 on Mercedes-Benz: causes and affected engines

P0507 means: idle control system: speed higher than expected.^[1][2] Mercedes-Benz has 6 documented faults that can trigger it, across 6 engines, including OM642, 2.7 CDI (OM612) and 3.2 CDI (OM613), 2.7 CDI (OM647) and 3.2 CDI (OM648) and 2.0 CDI (OM640). Only a diagnosis can confirm the cause on your car.

Documented faults

that can trigger it

Engines

used by Mercedes-Benz, with at least one of them

Mercedes-Benz models

with at least one of these faults

Urgency

Monitor

Reviewed on 2 November 20263 sources How we work

Documented faults in Mercedes-Benz engines that can trigger P0507

Grouped by engine or model, from most to least important. These are faults with carbon build-up in the intake and with the intake flaps: not all of them will necessarily set the code, and only a diagnosis confirms the cause on your car.

OM642

In Clase C W204, Clase E W211, Clase E W212, Clase G W463, Clase M W164, Clase M / GLE W166 and 12 more models

- Critical severityFrequency: CommonIntakeBroken swirl flaps in the intake manifoldYes: the plastic rods of the intake manifold's swirl flaps become brittle and can break at around 100,000-200,000 km. If a loose flap is sucked into a cylinder, it can hit the piston and destroy the engine; this is why removing them preventively is recommended.Repair (garage): €600–€1,200Appears at around 100,000 km

2.7 CDI (OM612) and 3.2 CDI (OM613)

In Clase C W203, Clase E W210, Clase M W163 and CLK C209

- Medium severityFrequency: CommonInjectionLeaking or sooty injectors on the 2.7 CDIYes: injection is the most cited fault in owner accounts for the ML 270 CDI (24 of 81) and one of the main ones for the 170 hp (16 of 122), with injector leaks and rough idle when cold. A German ML guide warns that soot on the injectors can be expensive.

2.7 CDI (OM647) and 3.2 CDI (OM648)

In Clase E W211 and Clase S W220

- Medium severityFrequency: CommonInjectionInjectors with leaking seals or sootYes. Injection is the most cited issue in the French entry for the E 270 CDI (11 of 54 testimonies) and for the 204 hp E 320 CDI (10 of 38), with leaking injector seals and replaced injectors. A German guide warns that soot on the injectors makes high-mileage diesels expensive to run.

2.0 CDI (OM640)

In Clase A W169 and Clase B W245

- Medium severityFrequency: OccasionalInjectionCarbon build-up in the injectorsYes, although with fewer cases than the EGR: the OM640's injectors can build up soot with use, which a specialist German source describes as a cause of expensive repairs. Owner testimonies place it as a secondary problem compared with the EGR or the Autotronic gearbox.

M276

In Clase C W204, Clase C W205, Clase E W212, Clase E W213, Clase M / GLE W166, Clase R W251 and 9 more models

- Medium severityFrequency: OccasionalIntakeCarbon build-up on the M276 intake valves (direct injection)Yes: like any direct-injection petrol engine, the M276 builds up carbon in the intake ports and valves; it usually becomes noticeable at high mileage and, according to one workshop, affects the twin-turbos more than the naturally aspirated 3.5.

M271

In Clase C W204, Clase E W212 and SLK R172

- Low severityFrequency: CommonIntakeCarbon build-up in the intake on the direct-injection EVO turbo and CGI versionsOn the direct-injection versions (EVO turbo and the short-lived 2003-2005 CGI), the M271 can build up carbon on the intake valves, a problem typical of petrol direct injection. It is treated with mechanical cleaning; good-quality petrol helps prevent it.

Common causes of P0507 on any make

From most to least likely, according to the sources.

1Vacuum leak or unmetered air entering after the throttle: cracked intake hose, PCV or brake servo hose, or manifold gasket.^[1][3]
2Throttle body dirty or sticking from carbon build-up, or idle air control (IAC) valve stuck open.^[1][2][3]
3Dirty mass airflow (MAF) sensor or incorrect coolant temperature signal.^[2][3]
4EVAP purge valve stuck open, letting vapours into the intake.^[1]

What to check first

The first diagnostic steps, from the most likely and cheapest to check to the most expensive.

1Use the diagnostic tool to check that the idle really is higher than the target and when it happens: cold, warm or with the air conditioning on.^[1]
2Look for unmetered air leaks with a smoke test on the intake: hoses, PCV, brake servo, gaskets and EGR.^[1][3]
3Clean the throttle body and the IAC valve, and carry out the throttle relearn with the tool if it is electronic.^[1][3]

Full guide to P0507: symptoms, diagnosis and whether you can drive

Parts related to code P0507 on Mercedes-Benz cars

The parts that most often cause this code. The code points to the circuit, not always the part: diagnose before you buy.

Inlet manifold
- Buy part at Autodoc (affiliate link, opens in a new tab)

Affiliate links: if you buy from these shops, MotorFiable may receive a commission at no cost to you. Check compatibility against the registration plate or VIN before ordering. Affiliate links

Frequently asked questions

Which Mercedes-Benz engines have faults that can trigger P0507?

OM642 (1 fault), 2.7 CDI (OM612) and 3.2 CDI (OM613) (1 fault), 2.7 CDI (OM647) and 3.2 CDI (OM648) (1 fault), 2.0 CDI (OM640) (1 fault), M276 (1 fault) and M271 (1 fault). Each fault has its own page with the affected years and versions, the symptoms and the repair cost.

What does code P0507 mean on a Mercedes-Benz?

Idle control system: speed higher than expected. The ECU has detected that the actual idle speed is consistently above the target it calculated itself, with a tolerance that AutoDTCs puts at around 200 rpm. It is a generic OBD-II code: it means the same on a Mercedes-Benz as on any other make.^[1][2]

Can I keep driving with P0507?

Monitor. According to the sources it will not leave you stranded, but a high idle raises consumption and can punish the automatic gearbox when engaging; get it repaired soon.^[1][3]

Sources

Every fact on this page links to its source. If you find an error, let us know.

P0507 – AutoDTCsAutoDTCs · Technical documentation · consulted 29 October 2026
OBD Fehlercode P0507CarWiki.de · Technical documentation · consulted 29 October 2026 · in German
P0507: OBD2 diagnostic trouble codeCarista · Technical documentation · consulted 29 October 2026