What does code P1227 mean?

Q: What does code P1227 mean?

Mechanical Guard Circuit Low Input. P1227 on a Jaguar indicates that the engine control module (ECM) has detected a low input voltage on the mechanical guard circuit, which is a safety circuit designed to monitor the electronic throttle body and cut power if a fault is detected. The ECM expects a certain voltage range on this circuit and sees a signal below the acceptable threshold, which can be caused by a wiring fault, a failing throttle body, or a poor connection.

DTC codes / Jaguar codes / P1227

P1227 · JaguarMechanical Guard Circuit Low Input

P1227 on a Jaguar indicates that the engine control module (ECM) has detected a low input voltage on the mechanical guard circuit, which is a safety circuit designed to monitor the electronic throttle body and cut power if a fault is detected. The ECM expects a certain voltage range on this circuit and sees a signal below the acceptable threshold, which can be caused by a wiring fault, a failing throttle body, or a poor connection.

SystemPowertrain

Code typeJaguar specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Guidance is general and written for Jaguar vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.