Diagnostic Trouble Code (DTC) Information

Diagnostic trouble code (DTC) information

Condition




Diagnostic trouble code (DTC) ECM-3420 is stored if the engine speed (RPM) is over 2500 rpm, engine coolant temperature (ECT) is above 40°C (104°F) and the signal from the rear knock sensor (KS) is too high or too low.

Substitute value
- ignition retarded for safety reasons
- reduced boost pressure

Possible source

Signal too high:
- short-circuit to supply voltage in the signal cable
- worn engine

Signal too low:
- open-circuit in signal cable
- contact resistance in terminals
- defective knock sensor (KS)
- short-circuit between knock sensor (KS) signal cables

Fault symptom[s]
- malfunction indicator lamp (MIL) lit