Technical Description of OBD-II Trouble Code
The performance of the exhaust valve control circuit for Cylinder 9 is not functioning properly.
What does that mean?
This is a generic powertrain diagnostic trouble code (DTC) that is applicable to many OBD-II vehicles (1996-newer). This includes vehicles from Dodge, Peugeot, Jeep, Chevrolet, Chrysler, and others. While it is a generic code, the specific repair steps may vary depending on the year, make, model, and engine configuration of the vehicle.
OBD-II trouble code P3470, along with related codes P3469, P3471, and P3472, are associated with the exhaust valve control circuit for Cylinder 9.
The purpose of the exhaust valve control circuit for Cylinder 9 is to deactivate the exhaust valve in order to enable the cylinder deactivation feature (such as the V4 mode of a V8 engine). This helps 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 by deactivating four of the engine cylinders. This is achieved through variable valve timing solenoids that turn the exhaust valves on and off as needed. This code specifically pertains to the number 9 cylinder, while the other three cylinders involved in this process are determined by the engine configuration and firing order of the cylinders. The number 9 cylinder’s variable valve timing solenoid is located on or near the exhaust manifold in the vicinity of that cylinder, based on the specific configuration and vehicle.
When the ECM detects a performance issue related to the voltage or resistance in the exhaust valve control circuit for Cylinder 9, it will set code P3470 and illuminate the check engine light, service engine soon light, or both. In some cases, the ECM may disable the injector to the number 9 cylinder until the issue is resolved and the code is cleared, resulting in a noticeable engine misfire.
Cylinder Deactivation Solenoids:
What is the severity of this DTC?
The severity of this code can range from moderate to severe, depending on the specific symptoms of the malfunction. A misfire should be addressed immediately, as it can cause permanent damage to internal engine components.
What are some of the symptoms of the code?
Symptoms of a P3470 trouble code may include:
What are some of the common causes of the code?
Causes for this P3470 code may include:
What are some P3470 troubleshooting steps?
The first step in troubleshooting any malfunction is to research the Technical Service Bulletins (TSB’s) specific to the vehicle’s year, model, and engine. This can save time and money, as it provides a known fix for a known issue.
The second step is to check the engine oil level and ensure it is at the appropriate level. Then, inspect all components associated with the exhaust valve control circuit for Cylinder 9 for any visible physical damage. Depending on the specific vehicle, this circuit may include several components, such as the variable valve timing solenoid, switches, fault indicators, and the ECM. Conduct a thorough visual inspection of the associated wiring to check for any obvious defects, such as scraping, rubbing, bare wires, or burn spots. Next, check the connectors and connections for security, corrosion, and damaged pins. Consult the specific technical data for the vehicle to verify the configuration and identify every component incorporated within the exhaust valve control circuit for Cylinder 1.
Advanced Steps
The advanced steps are highly specific to the vehicle and require advanced equipment for accurate execution. These procedures necessitate the use of a digital multimeter and the specific technical references for the vehicle. In this situation, an oil pressure gauge may also aid in the troubleshooting process to confirm the presence of an oil passage restriction.
Voltage Checks
The reference voltage and acceptable ranges may vary depending on the specific vehicle and circuit configuration. The specific technical data will include troubleshooting charts and the appropriate sequence to follow, assisting in an accurate diagnosis.
If this process reveals the absence of a power source or ground, continuity testing may be necessary to check the integrity of the wiring, connectors, and other components. Continuity tests should always be performed with the power removed from the circuit, and the normal readings for wiring and connections should be 0 ohms of resistance. Resistance or lack of continuity indicates faulty wiring that is open, shorted, or corroded, and it must be repaired or replaced.
What are some common repairs for this code?
Common Mistake
We always recommend seeking professional mechanical service to address this issue. However, if that is not possible, we offer the option to permanently delete this specific DTC. All other codes will continue to function. If you are interested in this option, please upload your ECU file to our portal.
