C0542 Diagnostic Trouble Code

C0542 is a kind of OBD-II Diagnostic C-Chassis Diagnostic Trouble Code.

It is considered generic because it applies to all makes and models of vehicles, although specific repair steps may be different depending on your car model.

Symptoms

Symptoms of a C0542 diagnostic trouble code may include:

Possible spark knock (detonation / pre-ignition)
Poor fuel economy
The engine oil will exhibit dilution from the ECUs attempts to increase engine temperature. Some vehicles advance the fuel injection timing slightly after top center to afterburn a small amount of fuel to increase exhaust temperatures. Some of this fuel enters the crankcase. When the ECU determines the necessity to regenerate the DPF, the service life of the oil be shortened significantly
Reduction in engine performance, especially at low RPM levels

Possible Causes :

Dirty air cleaner element Damaged DPF
A plugged converter will cause of host of driveability problems as well as set this code. A severely plugged converter will result in the inability to increase rpm when under load. Look for a code such as P0421 -- catalytic converter efficiency below threshold if the converter indicating a faulty converter.
Defective ECU strategies or components will prevent proper regeneration

Repair Processes :

If the engine displays a miss and there wasn't a code, determine which cylinder is misfiring. If the exhaust manifold is visible, spay or pour a small amount of water on each cylinder exhaust port. Water will evaporate immediately on good cylinders and slowly on the missing cylinder. If this can't be accomplished pull the plugs and check the condition. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code C0542 is not difficult to diagnose and repair. Thus, it always pays to have a qualified technician to look after your vehicle should this error code arise.

Diagnosing this code requires the engine to be in good running shape, without unmetered air entering the engine. If other codes that relates to misfiring condition, lean running or air entering the engine is present, then you must first fix those error codes before C0542.

Fortunately, C0542 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0542 Trouble Code For Specific Cars

C0542 Nissan Versa Cylinder #5 High To Low Side Short
C0542 Dkw-vemag Vemag-fissore Ignition Coil A Primary Circuit Malfunction
C0542 Ducati Panigale V4 Illuminated Entry Relay Circuit Open
C0542 Bentley 4.25-litre Battery Module Voltage Out Of Range
C0542 Daihatsu Freeclimber Gear Shift position short to battery
C0542 Moretti S Coupe Boost Calibration High
C0542 Porsche Cayman Type 987 Fuel Pump Monitor Circuit High Input