P0303 00

Misfiring, Cylinder 3.

SDI CGM SVG Version 1.58 Date:2018-12-07 CYL 1 CYL 2 CYL 3 CYL 4 F224F014

Fault symptom

Fault indicator lamp (for further information see WIS Fault diagnosis, general)

(Check Engine lamp flashes if diagnostics has detected a misfire that is harmful to the catalytic converter).

Uneven running and misfiring.

On-board diagnosis

Type of diagnosis:

Continuous
Each misfire is registered and evaluated two different ways depending on the type of misfire.
Test 1
•Affects emissions.
Test 2
•Harmful to the catalytic converter.

Enable criteria:


General conditions for this DTC
•Positive engine torque (negative torque = engine braking).
•Combustion signals from CDM are registered.
Test 1
•Total number of combustion signals registered.
Test 2
•The number of times no combustion signal is sent is tallied per cylinder every 200 engine revolutions. The total number of permissible misfires per 200 revolutions is indicated in a load and rpm-dependent matrix.

Fault criteria:


Test 1
•Total number of missing combustion signals more than 3%.
Test 2
•The number of times there was no combustion exceeds the number of permissible misfires.

Dependent:


P1312, P1315, P1341, P1342, P1343, P1344

System reaction to a fault:

None

OK report:

OK report occurs during ignition off, if no Fault report has been made during the driving cycle.

Fault handling:

Test 1
•Type II
•(See section Fault handling II, "Emission-related misfiring or fault in fuel system" for more information.)
Test 2
•Type I
•(See section Fault handling I, "Catalyst damaging misfiring" for more information).

Checking the wiring harness


Move the wiring harness at several spots and in several directions to reveal intermittent breaks and short-circuits. Check switches, connectors and crimp connections for oxidation, retracted pins and pin clamping force.

Diagnostic help

Diagnosis regards:

Fuel/air mixture too rich or too lean, insufficient compression, poor spark plugs causing incomplete combustion.

Functions in the diagnostic tool related to the fault:

Test value:
•Misfire Cyl 3
•Airmass Deviation from Calculated
•Additive Adaptation
•Multiplicative Adaption
Activation:
•Reset Misfire Counters
•Injector 3
•Ignition coil 3
•Fuel Pump
(See also description of readings/activations in diagnostic tool)