Misfiring

Fault symptoms
Misfiring

Conditions
The following conditions apply for the current fault symptom:
- No diagnostic trouble codes in the car with the current symptom description.

Diagnostic help
Start fault diagnosis by changing the spark plugs and then determine whether one or more cylinders are misfiring using the misfire counters.

If only one cylinder is misfiring, concentrate fault diagnosis to that cylinder and check compression, ignition trigger from the control module, ignition discharge module and, finally, injectors.

If more than one cylinder is misfiring, inspect components and cylinders that are common to all cylinders. Conduct a general check on connections and hoses first and then a thorough check on compression, ignition and fuel system.

Functions in the diagnostic tool related to the fault:
- Misfire Cyl 1.
- Misfire Cyl 2.
- Misfire Cyl 3.
- Misfire Cyl 4.
- Multiplicative Adaptation, unit %
- Additive Adaptation, unit mg/c.
- Closed loop, unit %.
- Purge Adaptation, unit %.
- Air mass deviation from calculated, unit %.
- Activating misfire counter reset.
- Activating ignition triggers.
- Activating injector test.
- Activating pump test.

See also the description of activations, for more information.
"Activate" Menu

Checking the wiring
Jiggle the wiring harness at several points and in different directions to detect intermittent breaks and short circuits. Observe the multimeter, diagnostic tool or test lamp during the check.