P0306

P0306

Diagnosis information - DME

Cylinder-specific misfire

NOTE 1:
The fault types have a special meaning in the case of misfires:
- Fault type Implausible signal: Exhaust-related fault after engine start
- Fault type Limit value not reached: Exhaust-related fault during driving
- Fault type Limit value exceeded: Fault damaging to catalytic converter

NOTE 2:
- The sum fault P0300 is always entered in addition to other misfires It is possible that misfires have occurred for one or more cylinders.
- Detecting the misfire can block the fuel injection for the remainder of the driving cycle after a permanent misfire is detected on the cylinder in question. Misfire detection remains active.

Diagnostic conditions
- Engine running
- Engine load > 4 % up to 25 %, depending on engine speed
- Intake air temperature > -30 °C (-22 °F)
- No fault in crankshaft sensor
- In the event of misfires while driving: level road conditions (= not a bumpy road)

Possible fault causes
- If misfires occur for only one cylinder:
--> electrical fault in the activation line between DME and ignition coil
--> Spark plug connector faulty
--> Ignition coil faulty
--> Spark plug faulty
--> Secondary air
--> Mechanical or electrical fault in injection valve
--> Valve seat or valve faulty
--> Valve lift control faulty
--> Exhaust system blocked/constricted
--> Foreign matter in intake system; this can also lead to sporadic misfires for changing cylinders

- If misfires occur for a bank:
--> Electrical fault or loose contact in the activation line to the solenoid valve of the camshaft control
--> Solenoid valve of camshaft control has electrical or mechanical fault or is blocked
--> Hall-sender rotor (sensor wheel) faulty / twisted out of position
--> Secondary air
--> Intake camshaft adjustment too slow
--> Intake camshaft timing incorrect
--> Outlet camshaft timing incorrect
--> Fault in valve lift control
--> Oxygen sensor faulty (also loose contact in wiring harness)
--> Exhaust system blocked/constricted
--> Foreign matter in intake system; this can also lead to sporadic misfires for changing cylinders

- If misfires occur for both banks:
--> Wrong / poor fuel
--> Tank empty
--> Water in tank
--> Use of an engine-block heater
--> Secondary air
--> Exhaust system blocked/constricted
--> Foreign matter in intake system; this can also lead to sporadic misfires for changing cylinders