P21CB Jaguar Xk Diagnostic Trouble Code

P21CB Jaguar Xk code definition:
P21CB is a kind of OBD-II Diagnostic P-Powertrain Diagnostic Trouble Code for Jaguar Xk.

P21CB Jaguar Xk shows up when there's an electrical problem that causes the fuel volume regulator to malfunction and open. It's quite an unusual problem and likely intermittent. Any code that causes the vehicle's engine to die while running should be fixed as soon as possible, as it can be dangerous for both the vehicle and the passengers of the vehicle.

Symptoms

Symptoms of a P21CB Jaguar Xk diagnostic trouble code may include:

The light may stay on or light intermittently as the DPF regenerates. The engine will be sluggish on acceleration.
Faulty PCM
If the DPF is not cleared the ECU will revert to the "Limp Home Mode" until the situation is corrected
Diminished fuel efficiency

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)
An air leak forward of the DPF will change the sensor readings resulting in the code

Common Misdiagnoses

IC Circuit High Voltage Problem
Control Module Throttle Actuator Position Performance Problem
Air Conditioning (A/C) Clutch Feedback Circuit High Voltage Problem
Cruise Vehicle Speed/Set Speed Difference Too High Problem
PCM Stack Overrun Problem

Repair Processes :

Once located, visually inspect the connectors and wiring. Look for rubbing, scraping, bare wires, worn spots or melted plastic connectors. With the valve disconnected, the red voltmeter lead should be attached to the IMRC valve power wire and the black voltmeter lead connected to ground.

Process Tips

Diagnostic trouble code P21CB Jaguar Xk 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 P21CB Jaguar Xk.

Fortunately, P21CB Jaguar Xk is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.