C21AC Nissan Commercial OBD Code

OBD/2 C21AC error code description and symptoms.

EGR Flow Insufficient Detected The EGR system is monitored during steady state driving conditions while the EGR is commanded on.
The test fails when the signal from the DPF EGR sensor indicates that EGR flow is less than the desired minimum. Vacuum supply EGR valve stuck closed EGR valve leaks vacuum EGR flow path restricted EGRVR circuit shorted to PWR VREF open to D.P.F. EGR sensor D.P.F. EGR sensor downstream hose off or plugged EGRVR circuit open to PCM VPWR open to EGRVR solenoid D.P.F. EGR sensor hoses both off D.P.F. EGR sensor hoses reversed Damaged EGR orifice tube Damaged EGRVR solenoid Damaged PCM Perform KOER self-test and look for DTC C21AC as an indication of a hard fault.

As long as the throttle plate remains closed, the idling speed and quality is controlled by the PCM via the idle control valve, and as can be seen from the above it should be clear that idle control on a gasoline engine is a complex affair. For instance, if the engine is started in sub-zero temperatures, the PCM will command the idling control valve to allow less air to enter the engine to enrich the air/fuel mixture to create a condition which is roughly analogous to how chokes worked on carburetted engines to control idling in cold weather.

C21AC Nissan Commercial Error Code Repair Process :

The rule of C21AC code when it comes to emissions-related vehicle repair is that any modification that changes the vehicle from a certified configuration to a non-certified configuration is considered tampering: this applies to both vehicle owners and repair facilities and is, therefore, a Federal offense. Replacing a catalyst with a straight pipe is one traditional example of idm input circuit malfunction/ ignition coil control circuit high voltage. Likewise, overriding the OBD C21AC error in system through the use of high-tech defeat devices or non-certified computer chips, for example, would also be considered tampering. The OBD system may, however, be repaired back to its original certified configuration with certified performance chips or appropriate aftermarket parts.

Common Causes of Nissan Commercial C21AC OBD2 Code

A common cause of code C21AC is the failure of IDM Input Circuit Malfunction/ Ignition Coil Control Circuit High Voltage, but there are several other possible causes as well, such as ;

Air fuel ratio (A/F) Sensor 1 Bank 1 circuit poor electrical connection
Faulty Intake Valve Timing Control Solenoid Valve
Fuel filler cap remains open or fails to close
Intake Valve Timing Control Solenoid Valve circuit poor electrical connection

C21AC is a kind of Chassis Trouble Code

Diagnosing chassis noises can be one of the most frustrating problems technicians face. Fortunately, manufacturers have engineered noise, vibration and harshness (NVH) diagnostic techniques and equipment to find the source of the noise.

Engine OBD 2 Codes website is a freeware resource center for engine trouble codes.

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C21AC Nissan Commercial OBD Code

C21AC Nissan Commercial Error Code Repair Process :

Common Causes of Nissan Commercial C21AC OBD2 Code

C21AC code for other Nissan cars