Powertrain
generic / SAE
P034C
Ion Sense System Performance
Some engines (notably Saab and some Mazda direct-injection units) use the spark plug as an ion-current sensor after spark to detect knock and misfire. This code reports a performance issue with the ion-sense input — typically a worn plug, loose secondary connection, or aged ion-sense module.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number3 / 4C
Possible causes
- Spark plugs worn high
- Ion-sense module aged medium
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 150–1500 €
- Estimated time: 1–4 h
- Component: ion sense module
- Component: spark plug
- Component: ignition coil
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012