C3973 Trouble Code

View C3973 obd/2 error code description and symptoms. C3973 engine photo

Variable Cam Timing Over-advanced (Bank 1) The comprehensive component monitor (CCM) monitors the VCT position for an over-advanced camshaft timing.
The test fails when the camshaft timing exceeds a maximum calibrated value or remains in an advanced position. Cam timing improperly set No oil flow to the VCT piston chamber Low oil pressure VCT solenoid valve stuck closed Camshaft advance mechanism binding (VCT unit) C3973 DTC is a check of the VCT unit.

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.

C3973 Error Code Repair Process :

OBD C3973 code and tailpipe testing are two different approaches to identify vehicles in need of repair. The OBD system looks for broken or malfunctioning emissions control components and air suspension disable switch circuit short to ground, while tailpipe tests sample a vehicle's exhaust to see if it is above or below certain prescribed limits. Given the robust nature of today's emissions control components, it is entirely possible for an individual component to C3973 malfunction without leading to an immediate increase in emissions at the tailpipe. In such cases, other components (like the catalyst) can temporarily compensate for the part that is broken however, these other components can only do double duty for so long before they, too, begin to malfunction. In addition, OBD also monitors for C3973 and other malfunctions in the fuel system problems that traditional tailpipe tests were not designed to identify. Most state and local areas also include a gas cap pressure test as part of an emission inspection.

C3973 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.

Common Causes of C3973

A common cause of code C3973 is the failure of Air Suspension Disable Switch Circuit Short To Ground, but there are several other possible causes as well, such as ;

Camshaft advance mechanism binding (VCT unit)
Damaged VCT phaser
Faulty Air fuel ratio (A/F) Sensor 1 Bank 1
Faulty select solenoid

C3973 code for all cars

You can view according C3973 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+C3973 Pierce-arrow Series

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

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