What does code P1240 mean?

Q: What does code P1240 mean?

Injector Circuit Cylinder 7 Intermittent. P1240 on a GM vehicle means the engine control module (ECM) has detected an intermittent fault in the electrical circuit for fuel injector number 7, which is typically on the odd-numbered bank of a V8 or V6 engine. The ECM monitors injector current and voltage while commanding the injector on and off, and it sets this code when the circuit momentarily opens, shorts, or behaves erratically without failing completely. Because the fault is intermittent, the injector may still fire most of the time, making the symptom hard to reproduce.

DTC codes / GM codes / P1240

P1240 · GMInjector Circuit Cylinder 7 Intermittent

P1240 on a GM vehicle means the engine control module (ECM) has detected an intermittent fault in the electrical circuit for fuel injector number 7, which is typically on the odd-numbered bank of a V8 or V6 engine. The ECM monitors injector current and voltage while commanding the injector on and off, and it sets this code when the circuit momentarily opens, shorts, or behaves erratically without failing completely. Because the fault is intermittent, the injector may still fire most of the time, making the symptom hard to reproduce.

SystemPowertrain

Code typeGM specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

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