U1018 Jaguar Mark is described as Intake Air Temperature (IAT) Circuit Malfunction. It's actually a general trouble code for a problem on IAT electrical circuit sensor, as it sends incorrect voltage input signals to the PCM. There are two wires dedicated for each coil; one is battery feed which usually comes from the distribution center, and the other one for the coil driver circuit from the PCM. The PCM grounds or ungrounds the circuit to activate or deactivate the coil.
SymptomsSymptoms of a U1018 Jaguar Mark diagnostic trouble code may include:
Possible Causes :
Look for damage to the tank indicating impact that may have damaged the fuel pump or sender. If the scan tool has that capability, and the scan tool can operate the IMRC valves, then the problem is either resolved and a simple code clearing is all that's left or a new PCM would be called for.
Diagnostic trouble code U1018 Jaguar Mark 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 U1018 Jaguar Mark.
Fortunately, U1018 Jaguar Mark is a fairly common OBD code, meaning that it applies to all makes and models of vehicles made after 1996.