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P3473 Cylinder 10 Deactivation/Intake Valve Control Circuit/Open GuideMechanic.Com Modern internal combustion engines are equipped with sophisticated technologies designed to improve fuel efficiency, performance, and emissions.
One such technology is cylinder deactivation, which allows certain cylinders to be temporarily disabled under light load conditions.
This system, while effective, is also complex and heavily reliant on precise electronic and mechanical control. When a fault occurs, the system sets a Diagnostic Trouble Code (DTC) to help identify the problem.
One such code is P3473: Cylinder 10 Deactivation/Intake Valve Control Circuit/Open. This article will explore the meaning, causes, symptoms, diagnostic approach, and repair strategies related to this code.
See Also: P3472 Cylinder 9 Exhaust Valve Control Circuit High
P3473 Cylinder 10 Deactivation/Intake Valve Control Circuit/Open
What Does DTC P3473 Mean?
Definition: P3473 – Cylinder 10 Deactivation/Intake Valve Control Circuit/Open
This code indicates that the Engine Control Module (ECM) or Powertrain Control Module (PCM) has detected an open circuit condition in the intake valve control circuit for cylinder 10 during cylinder deactivation operation.
An “open circuit” means there is a break or disconnection in the electrical circuit that prevents the solenoid controlling the intake valve lifter from functioning properly.
In simpler terms, when the ECM commands the intake valve to deactivate for cylinder 10, it cannot detect the electrical signal returning from the control circuit, suggesting that power isn’t reaching the solenoid or the circuit is broken.
How Cylinder Deactivation Works
Many V8 engines from manufacturers like General Motors use cylinder deactivation systems such as Active Fuel Management (AFM) or Displacement on Demand (DoD).
These systems help improve fuel efficiency by disabling certain cylinders when full engine power is not required, such as during highway cruising.
The Process:
- Oil Control: The ECM sends a signal to special solenoids that control the flow of engine oil to hydraulic lifters.
- Hydraulic Lifters: The hydraulic lifters collapse, which prevents the intake and exhaust valves from opening in selected cylinders.
- Cylinder Reactivation: When full engine power is required, the ECM re-pressurizes the lifters to restore normal valve operation.
When there’s a fault like P3473, the intake valve on cylinder 10 cannot be properly controlled, which disrupts cylinder deactivation and leads to system failure.
Vehicles Commonly Affected
P3473 commonly occurs in GM vehicles equipped with V8 engines that use AFM or DoD technology, including:
- Chevrolet Silverado, Suburban, Tahoe, Avalanche, Camaro
- GMC Sierra, Yukon, Denali
- Cadillac Escalade
- Other GM platforms with 5.3L, 6.0L, and 6.2L V8 engines
Other automakers may also use similar technology, but GM vehicles are most often associated with this code.
P3473 Cylinder 10 Deactivation/Intake Valve Control Circuit/Open
Symptoms of P3473
Depending on how the system fails, the symptoms may be mild or severe. Common symptoms include:
- Check Engine Light (CEL) On: The first and most obvious sign.
- Reduced Engine Performance: When cylinder deactivation fails, you may notice hesitation or sluggishness.
- Rough Idle: The engine may idle roughly if valve control is compromised.
- Poor Fuel Economy: Disabling cylinder deactivation often results in increased fuel consumption.
- Ticking or Tapping Noise: If the intake valve lifter is not properly activated, you may hear abnormal engine noises.
- Misfires: The affected cylinder may misfire if valve timing is severely affected.
Common Causes of P3473
Several issues can trigger this fault code:
- 1. Open or Broken Wiring: A damaged wire in the intake valve control circuit can break the electrical path, causing an open circuit.
- 2. Faulty Intake Valve Solenoid: The solenoid responsible for controlling oil flow to the lifter may fail internally, resulting in no electrical continuity.
- 3. Poor Electrical Connections: Corroded or loose connectors can interrupt circuit continuity.
- 4. Blown Fuse or Faulty Relay: Electrical protection devices may fail, cutting power to the solenoid.
- 5. Faulty ECM Driver: In rare cases, the ECM itself may fail to provide the correct voltage to the circuit.
- 6. Contaminated Oil: Dirty or degraded oil can affect solenoid operation indirectly, though it doesn’t typically cause an open circuit on its own.
Diagnosing P3473
Accurate diagnosis is crucial to avoid unnecessary repairs. Follow these steps:
1. Confirm the Code
- Use a professional-grade OBD-II scanner to read stored trouble codes and verify the presence of P3473.
- Look for related codes such as P3474 (Circuit Performance), P3475 (Circuit Low), or P3476 (Circuit High) that may provide additional clues.
2. Visual Inspection
- Inspect the wiring harness leading to cylinder 10’s intake valve control solenoid.
- Look for frayed, pinched, cut, or melted wires.
- Check for oil contamination at electrical connectors.
3. Check Connector Condition
- Disconnect the solenoid and inspect the terminals for corrosion, bent pins, or loose fitment.
4. Test Solenoid Continuity
- Use a multimeter to measure the resistance across the solenoid terminals.
- Typical resistance should be between 5–15 ohms.
- An infinite resistance reading indicates an open circuit.
5. Check Power and Ground Supply
- With the ignition on, verify voltage supply and ground at the solenoid connector.
- Lack of power or ground may indicate a wiring issue upstream.
6. Test ECM Output
- If the solenoid and wiring check out, verify that the ECM is sending the correct signal.
P3473 Cylinder 10 Deactivation/Intake Valve Control Circuit/Open
Repair Options for P3473
Once the root cause is identified, repairs may include:
1. Repair or Replace Wiring
- If damaged wires are found, repair them using high-quality connectors, heat shrink tubing, and proper splicing techniques.
2. Replace the Intake Valve Control Solenoid
- If solenoid resistance is out of specification or continuity is lost, replace the solenoid.
3. Clean or Replace Connectors
- Remove corrosion with electrical contact cleaner. Replace connectors if terminal damage is found.
4. Replace Blown Fuse or Faulty Relay
- If the circuit protection components have failed, replace them and verify the cause to prevent future failures.
5. Replace ECM (Rare)
- If ECM output testing confirms driver failure, reprogram or replace the ECM. This is typically a last resort after all other possibilities are ruled out.
P3473 Cylinder 10 Deactivation/Intake Valve Control Circuit/Open
Preventing P3473
While some causes of P3473 are unavoidable, many can be prevented through regular maintenance:
Change Oil Regularly:
- Use high-quality oil of the correct viscosity to keep hydraulic lifters and solenoids clean.
Inspect Electrical Connections:
- Periodically check connectors and wiring for wear or corrosion, especially in high-mileage vehicles.
Avoid Improper Modifications:
- Poorly installed aftermarket electrical components can damage sensitive circuits.
Respond Quickly to Early Symptoms:
- Don’t ignore rough idling, ticking noises, or intermittent warning lights.
The Consequences of Ignoring P3473
Ignoring this code can lead to:
- Long-term engine damage
- Poor fuel economy
- Increased emissions
- Complete failure of the cylinder deactivation system
- Potentially costly repairs if problems escalate
Conclusion
DTC P3473 – Cylinder 10 Deactivation/Intake Valve Control Circuit/Open indicates a disruption in the electrical circuit responsible for controlling cylinder 10’s intake valve during cylinder deactivation.
The root causes are typically electrical in nature—ranging from damaged wiring and faulty solenoids to failed connectors or ECM issues.
Accurate diagnosis involves a step-by-step process including visual inspections, continuity tests, voltage checks, and component testing. Most repairs involve replacing faulty solenoids or repairing damaged wiring.
Preventative maintenance, including regular oil changes and careful monitoring of engine performance, can minimize the risk of encountering this issue.
Addressing P3473 promptly ensures your engine runs efficiently, saves fuel, reduces emissions, and prevents larger, more expensive problems in the future.
- P3473 Cylinder 10 Deactivation/Intake Valve Control Circuit/Open - June 16, 2025
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