C1981 Trouble Code

View C1981 obd/2 error code description and symptoms. C1981 engine photo

Brake Switch Circuit Input Malfunction Indicates PCM did not receive a brake pedal position (BPP) input. Open or short in BPP circuit Open or short in stoplamp circuits Damaged PCM Malfunction in module(s) connected to BPP circuit. (Rear Electronic Module [REM] Windstar and LS6/LS8 or Lighting Control Module (LCM) Continental and Town Car. Damaged brake switch Misadjusted brake switch Check for proper function of stoplamps.

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.

C1981 Error Code Repair Process :

If your vehicle speed sensor range/performance check engine light is illuminated, it's best to take it in for diagnostic testing, which can feel like a hassle. Because while the lights vary in appearance from vehicle to vehicle, all have the same basic meaning: There's a problem with the car's emissions system. The on-board diagnostics system C1981 and engine control unit are in charge of monitoring a bunch of different vehicle speed sensor range/performance, and if they get a reading that's a little out of whack, up pops the check engine light.

C1981 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 C1981

A common cause of code C1981 is the failure of Vehicle Speed Sensor Range/Performance, but there are several other possible causes as well, such as ;

Failures of clutch motion/travel sensors.
Continuous oil flow to the VCT piston chamber
Faulty Mass Air Flow (MAF) sensor
1Camshaft Position Sensor circuit poor electrical connection

C1981 code for all cars

You can view according C1981 DTC for your car model. We selected several models to see obd2 solutions click and view it.

+C1981 Toyota Chaser

+C1981 Bentley 3.5-litre

+C1981 Dodge Intrepid

+C1981 Mercedes Clk 500

+C1981 Dacia Supernova

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

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