P2D16

Code

Generic P — Powertrain

Exhaust Flow Control Valve C Control Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 21 EN: 36 RU: 24

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Page language: EN

Causes

Stuck or seized exhaust flow control valve (carbon, corrosion, foreign object)
Failed valve actuator (electric motor or solenoid)
Open, shorted or corroded wiring or connector to the valve
Poor or intermittent ground or power supply to the actuator
Faulty position sensor or feedback circuit (if equipped)
Exhaust backpressure or mechanical obstruction preventing movement

Symptoms

Check Engine Light (MIL) illuminated
Abnormal or louder exhaust sound (valve stuck open or closed)
Reduced engine performance, hesitation or poor throttle response
Possible limp-home mode on some vehicles
Reduced fuel economy or increased emissions
Diagnostic trouble codes related to other exhaust control components

What to check

Read freeze-frame and freeze data; note conditions when the fault set (engine temp, rpm, load, voltage)
Attempt to reproduce while monitoring live data for commanded vs actual valve position (if position feedback available)
Visual inspection of valve, actuator, linkage, wiring and connector for damage, corrosion, contamination
Check battery voltage and chassis/engine grounds; low voltage can cause actuator faults
Check for exhaust leaks or obstructions near the valve that could prevent operation
Verify there are no related codes that could point to powertrain or control module issues

Signal parameters

Control command: PWM duty cycle or On/Off command from ECM (0–100% duty typical for PWM)
Actuator supply voltage: approximately battery voltage (~11–14.5 V) when commanded ON
Actuator resistance (solenoid/motor): typically low ohm range (varies by design) — consult vehicle data
Position sensor/feedback voltage (if equipped): 0–5 V range; should move consistently when commanded
Response time: valve should begin to move within a fraction of a second to a few seconds depending on design
No continuous high resistance, open circuit, or short to ground/power in the control wiring

Diagnostic algorithm

Retrieve and record freeze frame and mode 6/graph data. Note engine temp, rpm and vehicle speed when fault occurred.
Clear the code and attempt to re-create the fault under the same conditions while monitoring live data (command vs feedback).
Perform a visual inspection of the exhaust flow control valve C hardware, linkage and surrounding exhaust for carbon deposits, corrosion or physical obstruction.
Inspect connector and wiring for damage, corrosion, loose pins and poor contact. Wiggle harness while monitoring for intermittent changes.
With key on engine off, verify presence of battery voltage at the valve power terminal and good ground continuity to chassis. Re-check while commanding the valve via scan tool.
Measure actuator coil/motor resistance with meter (compare to service spec). Check for short to ground or open circuit.
Command the valve using a scan tool or apply appropriate bench voltage per manufacturer procedure to observe movement. Do not exceed vehicle battery voltage or apply reversed polarity.
If the actuator does not move but has correct power/ground, remove the valve and inspect for carbon or mechanical binding. Clean or replace as required.
If wiring or actuator tests fail, repair/replace damaged wiring or connector, then retest. If actuator is faulty, replace valve assembly or actuator.
After repair, clear codes and perform functional test and road test to verify proper operation and that the code does not return.

Likely causes

Valve actuator failed or seized from carbon buildup
Damaged harness or connector (rodent chew, corrosion, pin pushed out)
Loss of power or ground to the valve control circuit
Intermittent connection causing erratic command/feedback
Valve linkage binding or rusted pivot point
Control module issuing incorrect commands (less common)

Fault status

⚠️ Status

Exhaust Flow Control Valve C control/performance fault detected. MIL may be illuminated; ECM has logged a control circuit or performance failure for that valve.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 3.0 hours