C20D1 Diagnostic Trouble Code

C20D1 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 C20D1 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 :

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 missing ground strap or a rusty ground where the fuel tank is grounded to the frame. Check for damage to the wiring harness connector. Replace the oxygen sensor that is downstream from the catalytic converter on the side of the engine that does not contain cylinder #1. Also, if a oxygen sensor code stating "heater circuit malfunction" the sensor has most probably failed.

Process Tips

Diagnostic trouble code C20D1 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 C20D1.

Fortunately, C20D1 is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.

C20D1 Trouble Code For Specific Cars

C20D1 Chevrolet Deville Driver's / Passenger's Door Ajar Output Circuit Short to Battery
C20D1 Riley Two-point-six Hydraulic Oil Temperature Sensor Circuit High Input
C20D1 Fiat 501 Lamp Anti-Theft Indicator Circuit Open
C20D1 Citroen 7 Hp Flash To Pass Switch Circuit Open
C20D1 Vauxhall Movano Pressure Control Solenoid B Malfunction
C20D1 Chevrolet Equinox 2 Drivers Seat Belt Buckle Switch Resistance out of Range
C20D1 Gaz 32 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)