On a trip around Devon, I noticed that the engine in my 53-plate S-TYPE 3.0 was pinking when climbing certain hills, which is not something I would have expected from a computer-controlled engine. I overcame this problem to some degree by using the manual settings on the auto transmission and keeping in as low a gear as possible. There’s 72,000 miles on the clock, but the engine was replaced at 30,000 miles with a new unit supplied and fitted by Jaguar. The only fault code showing is ‘P1111’.
A The code ‘P1111’ normally indicates that all systems are functioning correctly and that the diagnosis check is complete. As you say, an electronically controlled engine should not be suffering from pinking. If this is the case, it may be that the one of the knock sensors is at fault; the sensor
should send a signal to the ECM to adjust the timing to prevent pinking. The left-hand knock sensor is located within the V of the engine, on the inside of the left-hand bank as viewed from the driver’s seat, while the right-hand sensor is located below the exhaust manifold on the outside of the cylinder block just to the rear of the alternator. The knock sensors should read 180-220KΩ when read with an ohmmeter. You should also check the continuity of the connecting wires. Other possible causes are the ECM, the 02 sensors, fuel pressure or air leaks in the inlet system, although given that no detrimental fault codes are present, the most likely cause is the knock sensor.
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