What does fault code P0033 mean?

The control module has detected a fault in the Turbocharger/Supercharger Bypass Valve 'A' Control Circuit (P0033). Measurements: • Turbocharger/Supercharger Bypass Valve 'A' Control Circuit – Coil Resistance (Resistance (Ω)): 3 - 30 Ω (typical) [Condition: Connector disconnected at 20°C] • Turbocharger/Supercharger Bypass Valve 'A' Control Circuit – Duty Cycle (PWM (%)): 5 - 95 % (modulates with target) [Condition: Engine running, actuator in control] • Turbocharger/Supercharger Bypass Valve 'A' Control Circuit – Supply Voltage (Voltage (V)): 11.8 - 14.4 V [Condition: Ignition ON at connector] Oscilloscope: Capture the PWM control signal. The square wave must have clean edges, a stable frequency (typically 30 - 200 Hz), and a distinct flyback spike on every switch-off. (Scale: 2 ms/div, 20 V/div)

What are the symptoms of fault code P0033?

Direct short to ground collapses sensor reference voltage Check Engine Light (MIL) illuminated Possible drivability or power reduction Risk of failing an emissions inspection

What causes fault code P0033?

Most likely: 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. Likely: Chafed or pinched wiring harness along the signal path to Turbocharger/Supercharger Bypass Valve 'A' Control Circuit Possible: Internal mechanical wear or carbon deposits inside Turbocharger/Supercharger Bypass Valve 'A' Control Circuit Rare: Defective internal output driver or reference circuit in the control module for Turbocharger/Supercharger Bypass Valve 'A' Control Circuit

How do you fix fault code P0033?

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 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.

Standard EOBD

P0033 - Dumpventil / bypassventil 'A' – styrekrets

Relatert:Dumpventil / bypassventil 'A', Ledningsnett og kontakter, Styreenhet (ECM/PCM)

System

Drivlinje (Motor og girkasse)

Kontakt oss Finn reparasjon

Teknisk beskrivelse

Styreenheten registrerer en feil i Dumpventil / bypassventil 'A' (P0033).

Multimeter Målepunkter & Nominelle Verdier

Målepunkt / Komponent	Måletype	Nominelt Målområde	Målevilkår
Dumpventil / bypassventil 'A' – spolemotstand	Motstand (Ω)	3 - 30 Ω	Frakoblet ved 20°C
Dumpventil / bypassventil 'A' – arbeidssyklus	PWM (%)	5 - 95 %	Motor i gang

Dumpventil / bypassventil 'A' – spolemotstandMotstand (Ω)

Børverdi:3 - 30 Ω

Frakoblet ved 20°C

Dumpventil / bypassventil 'A' – arbeidssyklusPWM (%)

Børverdi:5 - 95 %

Motor i gang

Oscilloskop Kurveformanalyse

2 ms/div, 20 V/div

Registrer PWM-styresignalet; rene flanker, stabil frekvens og flyback-spiss.

Mulige årsaker

Kortslutning til jord i signalledningen eller internt i Dumpventil / bypassventil 'A'

Kanal A:Sjekk dedikert ledningspar for kanal A i modulkontakten.

Gnagd eller klemt ledningsnett fram til Dumpventil / bypassventil 'A'

Mekanisk slitasje eller sotbelegg i Dumpventil / bypassventil 'A'

Defekt driver eller referanseutgang i styreenheten for Dumpventil / bypassventil 'A'

Symptomer

Kortslutning mot jord slår ut signalspenningen

Motorlampe (MIL) lyser

Mulig redusert kjørbarhet eller effekt

Risiko for underkjent EU-kontroll

Anbefalt tiltak

Sammenlign måleverdier mellom krets A og krets B.

Mål ledningens isolasjonsmotstand mot gods.

Sjekk matespenning og kontaktstykke ved Dumpventil / bypassventil 'A'.

Mål kontinuitet og jordspenningsfall (< 0.05 V) for Dumpventil / bypassventil 'A'.

Sjekk matning og driver i ECM-kontakten.

Mekanikerens tips

Bruk skannerens aktuatortest med oscilloskop på styresiden samtidig. Endres duty uten mekanisk respons, har ventilen kjørt seg fast.

Vanlige kombinasjoner

P0234

P2261

P0033

P0234, P2261, P0033 VW 1.4 TSI – Turbo Avlastningsventil N249 & N75 Teknisk Feilsøkingsguide

VOLKSWAGEN • 128 analyser

Vis alle diagnostiske kombinasjoner

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