P3408 Cylinder 1 Exhaust Valve Control Circuit High
OBD-II Trouble Code Technical Description
Cylinder 1 Exhaust Valve Control Circuit High
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) and applies to many OBD-II vehicles (1996-newer). That may include but is not limited to vehicles from Dodge, Peugeot, Jeep, Chevrolet, Chrysler, etc. Although generic, the exact repair steps may vary depending on year, make, model and engine configuration.
OBD-II trouble code P3408 and related codes P3405, P3406 and P3407 are associated with the cylinder 1 exhaust valve control circuit.
The purpose of the cylinder 1 exhaust valve control circuit is to turn off the exhaust valve to accommodate the cylinder deactivation feature (e.g. V4 mode of a V8 engine) to improve fuel economy during light load operation at idle or on the highway. The Engine Control Module (ECM) controls the 4 or 8 cylinder modes of the engine deactivating four of the engine cylinders. This process is accomplished by incorporating variable valve timing solenoids that turn the exhaust valves on and off as required. This code pertains to the number 1 cylinder and the other three cylinders in this process are determined by the engine configuration and the firing order of the cylinders. The ECM will limit cylinder deactivation to a cycle time of 10 minutes in V4 mode, and then return to V8 mode for 1 minute. The number 1 cylinder variable valve timing solenoid is mounted on or near the exhaust manifold in the vicinity of that cylinder based of the specific configuration and vehicle.
When the ECM detects voltage or resistance that is too high outside the normal expected value range within the cylinder 1 exhaust valve control circuit, code P3408 will be set and the check engine light, service engine soon light or both may be illuminated. In some circumstances, the ECM may disable the injector to the number 1 cylinder until the issue is corrected and the code has been cleared causing a noticeable engine misfire.
Cylinder Deactivation Solenoids:
What is the severity of this DTC?
The severity of this code can vary tremendously from moderate to severe depending on the specific symptoms of the malfunction. A misfire requires immediate attention because it can cause permanent damage to internal engine components.
What are some of the symptoms of the code?
Symptoms of a P3408 trouble code may include:
Increased fuel consumption Poor engine performance Engine misfire Service engine soon light illuminated Check engine light illuminatedWhat are some of the common causes of the code?
Causes for this P3408 code may include:
Faulty variable valve timing solenoid Low engine oil level or pressure Restricted oil passage Faulty or damaged wiring Corroded, damaged or loose connector Defective ECMWhat are some P3408 troubleshooting steps?
The first step in the troubleshooting process for any malfunction is to research the Technical Service Bulletins (TSB's) for the specific vehicle by year, model and engine. This can save you time and money because it is basically a known fix for a known issue.
The second step is to check the condition of the engine oil and confirm it is serviced to the appropriate level. Then locate all components associated with the cylinder 1 exhaust valve control circuit and look for obvious physical damage. Based on the specific vehicle, this circuit may incorporate several components including the variable valve timing solenoid, switches, fault indicators and the ECM. Perform a thorough visual inspection to check the associated wiring for obvious defects such as scraping, rubbing, bare wires, or burn spots. Next is to check the connectors and connections for security, corrosion and damaged pins. Consult the specific technical data for the vehicle to verify the configuration and identi
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