C20AD Diagnostic Trouble Code

C20AD 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 C20AD diagnostic trouble code may include:

Rich or lean exhaust
Fuel pressure too low
Engine surge
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected

Possible Causes :

A large air leak at or near the number one oxygen sensor would also cause a lean mixture.
Faulty IMRC actuator relay (if equipped)
Faulty IMRC actuator/sensor

Repair Processes :

It should be pretty close to battery voltage (12 volts). If not, then this is the circuit that has the problem. Look for missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector.

Process Tips

Diagnostic trouble code C20AD 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 C20AD.

Fortunately, C20AD is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C20AD Trouble Code For Specific Cars

C20AD Porsche Boxster Type 986 Fuel Pressure Regulator 1 Control Circuit Low
C20AD Mitsubishi Lancer Autolamp Sensor Input Circuit Short To Ground
C20AD Humber Super Snipe Right Rear Turn Lamp Circuit Short to Battery
C20AD Vignale 125 PWM Input Circuit Failure
C20AD Jeep Dakar Seat Driver Rear Up Switch Circuit Open
C20AD Ford Zephyr Motor Relay # 1 Circuit Failure
C20AD Chevrolet Chevette Driver Power Window Up Circuit Short To Ground