Fault Tree

OBD-II differential diagnosis

Every trouble code with repair data loaded. Structure decoding works for any well-formed J2012 code, including these and the ones we hold no repair data for.

Code library 5 codes

P0128
Coolant thermostat below regulating temperature
Fuel and air metering
3 causes
P0171
System too lean (bank 1)
Fuel and air metering
5 causes
P0301
Cylinder 1 misfire detected
Ignition system or misfire
5 causes
P0420
Catalyst system efficiency below threshold (bank 1)
Auxiliary emission controls
5 causes
P0455
Evaporative emission system leak detected (large)
Auxiliary emission controls
4 causes