Please fill the "Code Box" to find engine fault code.
|The all list of engine trouble codes.|
P0421 Engine Diagnostic Code
On 1999 and later P0421 engines, the instrument cluster has a built-in self-diagnostic mode that can be accessed by pressing and holding the instrument cluster SELECT/RESET button. Insert the ignition key and turn to the RUN position (but don't crank or start engine). Continue to press and hold the SELECT/RESET button (for 5 seconds) until the word TEST is displayed by the odometer. Release the SELECT/RESET button within three seconds after the word TEST is displayed to begin the self-diagnostic mode.
P0421 engine code provides below are generic codes that may not apply to all vehicles. Car manufacturer uses specific P0421 DTC code that are different from the codes shown below. Foreign vehicles may also use DTC codes different from the generic Engine Diagnostic codes.
P0421 Diagnostic Trouble Code Meaning And Solution
|Powertrain Problem||SAE - Generic||Auxiliary Emission Controls||21 Engine Fault Code|
Starting letter P diagnostic code shows that there are problems in engine, transmission and emissions systems.
Don't forget ! If your P0421 engine code not resolved on and there are trouble codes in your computer, your vehicle will not pass an OBD 2 emissions test. The light must be off and there must be no codes in memory to pass an OBD 2 emissions test. In addition, all of the OBD II self-monitors that check for faults must have run and completed without finding any further problems to pass the test.