What Does P3448 Mean?
The ECM has detected an abnormally high voltage in the cylinder 6 exhaust valve control solenoid circuit. The voltage on the control line exceeds the expected threshold when the solenoid is not being commanded, indicating a short to power source. This prevents the ECM from properly controlling cylinder 6 exhaust valve deactivation.
Common Causes
35%
Short to battery voltage in the cylinder 6 exhaust valve solenoid wiring
30%
Failed cylinder 6 exhaust valve solenoid with internal short to power
20%
ECM driver failure causing uncontrolled high voltage output
15%
Miswired or cross-pinned VLOM connector
Diagnostic Steps
1
Step 1: With KOEO, measure voltage at the cylinder 6 exhaust valve solenoid control wire. Expect near 0V when not commanded — above 5V confirms the fault.
2
Step 2: Disconnect the solenoid and recheck harness-side voltage. A drop to normal implicates the solenoid; persistent voltage implicates wiring.
3
Step 3: Inspect wiring routing for contact with B+ sources. Check especially near power distribution, alternator, and ignition circuit areas.
4
Step 4: Measure solenoid resistance and check for shorts between terminals and the solenoid housing.
5
Step 5: Use bi-directional scan tool controls to command the solenoid while monitoring voltage to verify ECM driver function.
Estimated Repair Cost
$150 - $800
Parts + labor, varies by vehicle and location
The ECM has detected an abnormally high voltage in the cylinder 6 exhaust valve control solenoid circuit. The voltage on the control line exceeds the expected threshold when the solenoid is not being commanded, indicating a short to power source. This prevents the ECM from properly controlling cylin...
The most common cause of P3448 (Cylinder 6 Exhaust Valve Control Circuit High) is: Short to battery voltage in the cylinder 6 exhaust valve solenoid wiring
Typical repair costs for P3448 range from $150 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive. Cylinder deactivation will be disabled. Repair the short-to-voltage condition to prevent potential ECM driver circuit damage.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P3448 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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