C1997 Diagnostic Trouble Code

C1997 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 C1997 diagnostic trouble code may include:

Misfire
Misfire
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
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

Possible Causes :

A large vacuum leak would cause a massive amount of un-metered air to enter the intake manifold resulting in an overly lean mixture.
Faulty IMRC actuator/sensor
An air leak forward of the DPF will change the sensor readings resulting in the code

Repair Processes :

Look at the plug wires to make sure they are not burnt or laying on the exhaust. Use the DVOM to test resistance and continuity on all system circuits if actuator and sensor resistance levels are in compliance with manufacturer's specifications. Look for damage to the tank indicating impact that may have damaged the fuel pump or sender.

Process Tips

Diagnostic trouble code C1997 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 C1997.

Fortunately, C1997 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C1997 Trouble Code For Specific Cars

C1997 Alpine Berlinette Air Bag Passenger Circuit Short to Battery - Loop #2
C1997 Turner 1100 Pedal Position Rearward Switch Circuit Short to Battery
C1997 Mg Magna Air Suspension RR Height Sensor Circuit Short To Ground
C1997 Maserati Quatroporte Transmission Fluid Temperature Sensor Circuit High Input
C1997 Lotus Extreme Traction Control Motor Potentiometer Circuit Open
C1997 Willys-overland 685 SCP (J1850) Invalid or Missing Data for Powertrain Status Request
C1997 Citroen Gs Fuel Level Sensor Circuit Range/Performance