P3470

Code

Generic P — Powertrain

Cylinder 9 Exhaust Valve Control Circuit Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 26 EN: 35 RU: 25

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Page language: EN

Causes

Faulty exhaust valve actuator/solenoid for cylinder 9
Open, shorted, or corroded wiring or connector to the exhaust valve actuator
Poor ground or low supply voltage to the actuator circuit
Oil contamination or mechanical binding of the exhaust valve/actuator
Intermittent connector contact caused by broken terminals or chafed harness
Faulty PCM or internal driver failure

Symptoms

Malfunction Indicator Lamp (MIL) / Check Engine Light illuminated
Reduced engine performance or power delivery
Rough idle or occasional misfire on cylinder 9
Degraded fuel economy and increased emissions
Unusual exhaust noise or valve-related tapping sound (if mechanical binding)
Stored freeze-frame data showing condition at fault occurrence

What to check

Read and record freeze-frame and live data with a scan tool; note any related codes
Check for other cylinder-specific or cam/timing codes (may point to root cause)
Visually inspect wiring and connector for cylinder 9 exhaust valve actuator for damage, corrosion, oil, or loose terminals
Back-probe connector to verify supply voltage and ground with ignition ON and during commanded operation
Measure actuator coil resistance and compare to specification
Wiggle harness while monitoring live data to reproduce intermittent faults

Signal parameters

Supply voltage to actuator: nominal battery voltage (~12 V) with ignition ON (may be switched fused feed)
Control signal: often a ground-switched or PWM signal from PCM; expected 0–12 V range depending on design
Typical coil/solenoid resistance: commonly in the low ohms to tens of ohms (e.g., ~5–40 Ω) — consult vehicle spec
No open circuit or short to battery/ground; continuity from PCM connector to actuator connector
PWM frequency and duty cycle vary by manufacturer; signal should change when actuator is commanded

Diagnostic algorithm

Use a scan tool: read codes, freeze-frame, and live data. Note if code is current or historic and check for related cam/crank or cylinder codes.
Visually inspect the cylinder 9 exhaust valve actuator, pins, and harness for damage, oil contamination, corrosion, or disconnection.
With ignition ON (engine off), back-probe the actuator connector: verify fused supply voltage and a good ground reference. Record voltages.
Command the actuator via scan tool (if possible) and observe changes in voltage, duty cycle, or actuator movement. Listen/observe for mechanical response.
Measure actuator coil resistance (engine off, connector disconnected). Compare to factory spec. Check for short to ground or battery.
Perform continuity check between PCM control pin and actuator connector; check for intermittent opens by wiggling harness.
If wiring/connectors are good and actuator does not respond or resistance out of spec, replace the exhaust valve solenoid/actuator for cylinder 9.
If actuator replacement does not clear the code, test/replace PCM or further diagnose PCM driver circuit per manufacturer procedure.
After repair, clear codes and road test while monitoring live data to confirm the issue is resolved and code does not return.

Likely causes

Defective exhaust valve solenoid/actuator (most common)
Wiring harness damage or poor connector connection at cylinder 9 circuit
Open or high-resistance ground/supply to the actuator
Actuator mechanically stuck (oil sludge or debris)
PCM driver fault (least common)

Fault status

⚠️ Status

Powertrain DTC P3470 — Cylinder 9 Exhaust Valve Control Circuit Performance. Abnormal signal detected from the exhaust valve actuator/solenoid circuit for cylinder 9; inspect actuator, wiring, supply/ground, and PCM.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0-3.0 hours