P00C0

Code

Generic P — Powertrain

Turbocharger/Supercharger Bypass Valve B Control Circuit

Brand: Generic

Type: P — Powertrain

Views: UK: 20 EN: 147 RU: 34

AI status

Completed

ready

Completed 100%

Page language: EN

Causes

Open or shorted wiring in the bypass valve B control circuit
Corroded, loose or damaged connector at the bypass valve
Failed bypass/recirculation valve B solenoid or actuator (stuck or electrically open)
Poor or missing ground or supply voltage to the valve
Blown fuse or damaged relay supplying the circuit
ECM/PCM driver fault (rare)

Symptoms

Check Engine Light (MIL) illuminated
Reduced engine power or poor boost control
Turbo/supercharger underboost or overboost conditions
Hesitation, reduced throttle response or limp-home mode
Abnormal or loud bypass/wastegate noises if valve is stuck
Erratic idle or surging if recirculation valve is not operating

What to check

Read and record freeze frame and full scan data; confirm P00C0 is current or stored
Use a scan tool to monitor commanded bypass valve B duty cycle/position and actual response
Visually inspect wiring and connector for damage, corrosion, water, or disconnection
Check fuses/relays that feed the bypass valve circuit
Measure voltage supply and ground at the valve connector with connector connected and engine off/on
Measure resistance of the valve solenoid coil (specs vehicle-specific) and check for open/short

Signal parameters

Control type: either switched 12 V or PWM control from ECM (vehicle-specific)
Typical coil resistance (generic): ~5–40 ohms (measure against vehicle spec)
Idle/no-command expected: open-circuit or ~0–1 V on signal/driver side (depending on design)
Commanded-on expected: battery voltage (approx. 9–14 V) or PWM duty cycle up to 100% (observe duty % with scan tool/oscilloscope)
Ground reference: near 0 V; poor ground will show elevated resistance/voltage drop
When commanded, the valve/solenoid should show a change in current draw and/or audible actuation (vehicle-specific)

Diagnostic algorithm

Retrieve freeze frame and live data. Confirm code P00C0 and check when it set (conditions, load, RPM).
Visually inspect the bypass valve B, connector, and harness for damage, corrosion, or water. Repair as needed.
Check relevant fuses/relays for the boost control circuit. Replace if blown or faulty.
With ignition ON (engine off), backprobe the valve connector: verify battery voltage supply on the power pin (if applicable) and a good ground reference.
Command the bypass valve B ON/OFF with a scan tool while monitoring the control wire: verify the ECM outputs the expected voltage or PWM signal. Use an oscilloscope for intermittent/complex PWM checks.
Measure coil resistance at the valve. Compare to vehicle specification. If open or shorted, replace the valve.
If the ECM commands the valve but it does not move, bench-test or swap with a known-good valve to confirm mechanical operation.
If the valve and harness test good but there is no or incorrect command from the ECM, inspect wiring continuity between ECM and valve, looking for opens/shorts to power or ground.
Repair or replace damaged wiring, connectors, or the valve as indicated. After repair, clear codes and perform road test under conditions that previously set the code.
If fault returns and wiring/valve are good, consult manufacturer guidance for ECM/PCM driver testing or reprogramming; consider module replacement only after confirming external circuitry is good.

Likely causes

Damaged or disconnected connector at the bypass valve
Open or shorted harness between ECM and valve
Failed bypass valve solenoid (electrical or mechanical)
Bad ground at the valve or related harness
Blown fuse or faulty relay supplying the valve circuit

Fault status

⚠️ Status

ECM detected a malfunction in Turbocharger/Supercharger Bypass Valve B control circuit — abnormal, missing, or erratic control signal. Fault stored; driveability/boost control may be affected.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.5 hours