P249E Mercedes E 400 Diagnostic Trouble Code

P249E Mercedes E 400 code definition:
P249E is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Mercedes E 400.

P249E Mercedes E 400 is defined as Knock Sensor Circuit Range Performance (Bank 1 or Single Sensor). This refers to camshaft timing, which in this case is over-retarded. So if the problem persists despite of your diagnosis, then you should never hesitate to take your vehicle to your dealer or to a qualified mechanic.

Symptoms

Symptoms of a P249E Mercedes E 400 diagnostic trouble code may include:

Excessive exhaust leak
Hesitation upon acceleration
Malfunction Indicator Lamp (MIL) illuminated
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.

Common Misdiagnoses

Vehicle Speed Output Circuit Problem
Cruise Control Servo Indicates Low Problem
A/C System High Pressure High Temperature Problem
PCM Stack Overrun Problem
Transmission Control Module Reprogrammable Memory Problem

Repair Processes :

If all testing has passed so far yet you still have the same code, check your scan tool and see if it can open and close the IMRC valve. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground.

Process Tips

Diagnostic trouble code P249E Mercedes E 400 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before P249E Mercedes E 400.

Fortunately, P249E Mercedes E 400 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.