P3440

Code

Generic P — Powertrain

Cylinder 5 Exhaust Valve Control Circuit High

Brand: Generic

Type: P — Powertrain

Views: UK: 20 EN: 33 RU: 26

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Page language: EN

Causes

Short to battery (12V) on cylinder 5 exhaust valve solenoid/control circuit
Faulty exhaust valve actuator / VVT solenoid for cylinder 5
Corroded, bent or disconnected connector or wiring harness at solenoid or ECM
Poor or missing ground at the ECM or solenoid
Internal ECM driver fault
Low engine oil level, dirty oil, or oil pressure problems causing actuator malfunction

Symptoms

Check Engine Light (MIL) on and related DTC stored
Possible rough idle or misfire if actuator is stuck or timing is off
Reduced engine performance or poor fuel economy if cam timing is affected
Erratic cam timing or audible valve/cam noise in severe mechanical cases
Intermittent faults that may clear with ignition cycles

What to check

Read and record freeze frame and freeze data with a scan tool; note operating conditions when DTC set
Inspect connector and wiring to cylinder 5 exhaust valve solenoid for corrosion, damage, pin push‑out, or water intrusion
Check engine oil level and condition; inspect for oil quality and pressure issues
Use a DVOM to check battery voltage at the solenoid supply and engine ground availability
Measure resistance of the solenoid coil (remove connector) and compare to OEM specification
Backprobe the control pin and monitor voltage with key on/engine running or use scope to view PWM signal from ECM

Signal parameters

Typical solenoid coil resistance: consult OEM — commonly in the range ~6–30 ohms (measure at ambient temperature)
Control signal idle voltage: near 0–1 V when driver is off; high when commanded depending on PWM duty (if circuit is shorted to 12V the control line will show ~battery voltage)
Supply voltage at solenoid supply pin: battery voltage (~11–14.5 V) with ignition on
PWM control frequency: often 10–200 Hz depending on manufacturer; duty cycle varies with commanded cam timing — consult service data
Expected behavior: when commanded off, control line should not remain at battery voltage; when commanded on, oscilloscope shows PWM waveform — if steady battery voltage present, suspect short to 12V or driver fault

Diagnostic algorithm

Connect a scan tool, read P3440 and any related codes; record freeze frame data and attempt to reproduce the fault.
Visually inspect harness and connector at cylinder 5 exhaust valve solenoid for damage, corrosion, oil or water. Repair as needed.
Verify engine oil level and condition; top/replace oil if out of spec. Low oil can cause VVT/electro-hydraulic actuator faults.
With ignition OFF, disconnect the solenoid connector and measure coil resistance across the solenoid pins. Compare to OEM spec. Replace solenoid if out of range or open/shorted.
With connector disconnected, check for short to battery: measure voltage between the control pin and ground with the ignition ON — if battery voltage present with connector removed, inspect harness for short to constant 12V.
Check continuity between the solenoid control pin and the ECM control pin; check for unexpected continuity to battery (short) or other circuits.
Backprobe the control wire with the connector connected and engine running (or commanded test). Use an oscilloscope to verify PWM waveform and proper voltage swing. If waveform shows steady battery voltage, suspect short or faulty ECM driver.
Verify good ground at the ECM and engine block ground straps; repair high resistance grounds.
If wiring and solenoid check good, consider replacing the solenoid. If new solenoid does not clear the code and wiring/grounds are good, suspect ECM driver fault and follow OEM ECM replacement/repair procedures.
After repairs, clear codes and road test to ensure fault does not return. If intermittent, monitor with logs or extended test drive.

Likely causes

Wiring short to constant 12V at the solenoid connector
Failed solenoid coil (internal short or open)
Damaged connector pins or water ingress causing high voltage feedback
Broken ground or high resistance ground at ECM/engine block
ECM output driver failed

Fault status

⚠️ Status

Circuit High detected on Cylinder 5 Exhaust Valve Control — voltage higher than expected (possible short to battery, solenoid fault, wiring/connector issue, or ECM driver failure).

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours