Possible causes

– Low oil pressure
– Restricted oil passage
– Engine mechanical condition
– Multiple Displacement System (MDS) Solenoid fault

Tech notes

Although in some cases changing the engine oil may fix the problem, usually the Multi Displacement System Solenoid may need to replaced.

When is the code detected?

The Engine Control Module (ECM) has detected a lean condition on bank 1 while in the 4 cylinder mode

Symptoms

– Engine Light ON (or Service Engine Soon Warning Light)

P3400 DODGE Description

The Multi-Displacement System (MDS) deactivates four of the V8’s cylinders when the throttle is closed or at steady speeds.