C0138 Diagnostic Trouble Code

C0138 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 C0138 diagnostic trouble code may include:

If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Corroded or damaged connector
Reduction in engine performance, especially at low RPM levels
The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.

Possible Causes :

Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Low fuel pressure caused by a clogged filter, failing fuel pump, failed fuel pressure regulator or clogged or leaking injectors.
Fuel with a large percentage of sulfur will clog the DPF quickly

Repair Processes :

Find out what kind of system you have and verify that voltage to the fuel level sensor is present at the fuel pump wiring harness. Oxygen sensors signal the engine management computer the amount of oxygen present in the exhaust, which is used in determining and controlling the fuel ratio. 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.

Process Tips

Diagnostic trouble code C0138 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 C0138.

Fortunately, C0138 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C0138 Trouble Code For Specific Cars

C0138 Nissan Be-1 Climate Control Recirculation Actuator Out of Limits
C0138 Maserati 4200 Gt Transmission Fluid Pressure
C0138 Abarth 600 A Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)
C0138 Pininfarina Chronos Engine Speed Input Circuit Intermittent
C0138 Gmc Terrain Park Brake Valve Solenoid #1 Sense Input Circuit Short to Gound
C0138 Westfield Xtr SCP (J1850) Invalid or Missing Data for Navigation
C0138 Lanchester Light Six Speed Wheel LF Input Signal Missing