P0033 - Turbocharger/Supercharger Bypass Valve 'A' Control Circuit
System
Powertrain (Engine & Gearbox)
Technical Description
The control module has detected a fault in the Turbocharger/Supercharger Bypass Valve 'A' Control Circuit (P0033).
Multimeter Test Points & Nominal Values
| Test Point / Component | Measurement | Nominal Target Range | Test Condition |
|---|---|---|---|
| Turbocharger/Supercharger Bypass Valve 'A' Control Circuit – Coil Resistance | Resistance (Ω) | 3 - 30 Ω (typical) | Connector disconnected at 20°C |
| Turbocharger/Supercharger Bypass Valve 'A' Control Circuit – Duty Cycle | PWM (%) | 5 - 95 % (modulates with target) | Engine running, actuator in control |
| Turbocharger/Supercharger Bypass Valve 'A' Control Circuit – Supply Voltage | Voltage (V) | 11.8 - 14.4 V | Ignition ON at connector |
Connector disconnected at 20°C
Engine running, actuator in control
Ignition ON at connector
Oscilloscope Waveform Analysis
2 ms/div, 20 V/divPossible Causes
Short to ground on the signal wire or an internal short circuit within Turbocharger/Supercharger Bypass Valve 'A' Control Circuit
Channel A:Verify dedicated wiring pins and signal pair for circuit A against the schematic.
Chafed or pinched wiring harness along the signal path to Turbocharger/Supercharger Bypass Valve 'A' Control Circuit
Internal mechanical wear or carbon deposits inside Turbocharger/Supercharger Bypass Valve 'A' Control Circuit
Defective internal output driver or reference circuit in the control module for Turbocharger/Supercharger Bypass Valve 'A' Control Circuit
Symptoms
Recommended Solution
Compare signal voltage and resistance between circuit A and companion circuit B at module connector.
Check wire insulation resistance to ground (< 1 Ω indicates harness pinched or chafed against engine block/chassis).
Verify loaded supply voltage and harness terminal pins at Turbocharger/Supercharger Bypass Valve 'A' Control Circuit.
Check circuit continuity and ground-side voltage drop (< 0.05 V) for Turbocharger/Supercharger Bypass Valve 'A' Control Circuit.
Check supply and the low-side driver at the ECM connector. Replace the actuator or repair the circuit based on the readings.
Mechanic's Tip
Use the scan-tool output test with the scope on the control side at the same time. If duty changes but the actuator does not move, the valve is stuck — not the electrical fault you were chasing.