What does code P1790 mean?

Q: What does code P1790 mean?

Ignition Supply Malfunction. P1790 on a Jaguar means the engine control module (ECM) has detected a problem with the ignition supply circuit, which is the switched power feed that energises the ignition coils and related engine management components. The ECM monitors this supply and flags the code when the voltage is outside the expected range during key-on or engine running, indicating an open circuit, high resistance, or short to ground or power.

DTC codes / Jaguar codes / P1790

P1790 · JaguarIgnition Supply Malfunction

P1790 on a Jaguar means the engine control module (ECM) has detected a problem with the ignition supply circuit, which is the switched power feed that energises the ignition coils and related engine management components. The ECM monitors this supply and flags the code when the voltage is outside the expected range during key-on or engine running, indicating an open circuit, high resistance, or short to ground or power.

SystemPowertrain

Code typeJaguar specific

SeverityMedium

Fix difficultyIntermediate

AreaTransmission

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