What Does P3403 Mean?
The cylinder 1 deactivation intake valve control circuit voltage is below the expected range. The ECM detects lower than normal voltage when attempting to activate the solenoid.
Common Causes
40%
Short to ground in cylinder 1 deactivation solenoid circuit
30%
Internal short in deactivation solenoid
20%
Damaged or pinched wiring harness
10%
Corroded ground connection
Diagnostic Steps
1
Step 1: Disconnect cylinder 1 deactivation solenoid and measure resistance to ground; should be open circuit
2
Step 2: Inspect wiring harness for damage, chafing, or contact with hot engine components
3
Step 3: Check for proper ground connection at ECM and engine ground points
4
Step 4: Test solenoid resistance when disconnected; compare to specifications
5
Step 5: Verify ECM is not showing low system voltage codes which could cause false low voltage readings
Estimated Repair Cost
$120 - $800
Parts + labor, varies by vehicle and location
The cylinder 1 deactivation intake valve control circuit voltage is below the expected range. The ECM detects lower than normal voltage when attempting to activate the solenoid.
The most common cause of P3403 (Cylinder 1 Deactivation/Intake Valve Control Circuit Low) is: Short to ground in cylinder 1 deactivation solenoid circuit
Typical repair costs for P3403 range from $120 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. Cylinder 1 will remain active continuously, resulting in minor decrease in fuel economy.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P3403 to identify the root cause.
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Quick Info
Category
Powertrain
System
Cylinder Deactivation System
Difficulty
Type
Generic (SAE)
Recommended Tools
OBD2 Scanner
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