The most common cause for this Rover 2300 P3998 type of failure is due to liquids spilled on the upshift/downshift switch. Open or shorted electrical wiring, damaged, corroded, or disconnected wiring or connectors are also a viable possibility.
Common Symptoms For Rover 2300 P3998
If the initial resistance is within specifications, leave the leads of the digital volt/ohmmeter connected and heat the resistor with a heat gun
Should all system circuitry and sensors check out and the transmission is in good working order, suspect a faulty PCM but keep in mind that PCM failure is rare and PCM replacement will require reprogramming.
The valve is controlled by the PCM (or a similar controller) using inputs from sensors and other controllers in the controller area network (CAN). The CAN represents a communication bus that allows multiple microcontrollers to communicate with one another without the need for a host computer
Individual control module failure is rare but possible
IC Module 4X Ref Circuit Intermittent, No Pulses
BBV Sensor Circuit Low Voltage
Kick-Down Switch Failed Short
Rover 2300 P3998 Troubleshooting
When you put your foot down on the brakes you expect your car to quietly slow down and come to a stop. The power your foot applies on the brake pedal is assisted by hydraulic pressure. Your foot's force engages a piston and caliper with brake pads attached (bonded abrasive and heat resistance metal or ceramic) to put pressure on the rotor. Rover 2300 P3998 OBD2 specifically refers to the camshaft (cam) timing. In this case, if the cam timing is over-retarded, the engine light will be illluminated and the code will be set.
How to turn off Rover 2300 P3998 check engine light ?
There are two ways to turn off the check engine light:
A repair technician can do so once repairs have been made.
The OBD II can automatically turn it off when it fails to detect the problem after several diagnostic cycles.