What does fault code P0501 mean?

The control module has detected a fault in the Vehicle Speed Sensor (VSS) 'A' Range/Performance (P0501). The reported signal is electrically valid but disagrees with other operating parameters (RPM, load, or other sensors). Measurements: • Vehicle Speed Sensor (VSS) 'A' Range/Performance – Supply Voltage (Voltage (V)): 5.0 V or 12.0 V (type dependent) [Condition: Ignition ON at connector] • Vehicle Speed Sensor (VSS) 'A' Range/Performance – Signal Low / High Level (Voltage (V)): Low 4.5 V (square-wave toggle) [Condition: Engine barred over slowly] • Signal Ground Voltage Drop (Voltage (V)): < 0.05 V [Condition: Under load to ground] Oscilloscope: Capture the square-wave during cranking. Edges must be crisp and levels stable; rounded edges or missing pulses indicate a worn trigger wheel or excessive air gap. (Scale: 1 ms/div, 2 V/div)

What are the symptoms of fault code P0501?

Signal plausibility mismatch between measured reading and ECU target model Check Engine Light (MIL) illuminated Possible drivability or power reduction Risk of failing an emissions inspection

What causes fault code P0501?

Most likely: Vehicle Speed Sensor (VSS) 'A' Range/Performance is electrically operational but performing outside calibrated tolerance 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 Vehicle Speed Sensor (VSS) 'A' Range/Performance Likely: Poor ground connection or excessive voltage drop (> 0.1 V) at the ground point for Vehicle Speed Sensor (VSS) 'A' Range/Performance Rare: Defective internal output driver or reference circuit in the control module for Vehicle Speed Sensor (VSS) 'A' Range/Performance

How do you fix fault code P0501?

Compare signal voltage and resistance between circuit A and companion circuit B at module connector. Log component live data across varying load points and verify plausibility against engine target model. Verify loaded supply voltage and harness terminal pins at Vehicle Speed Sensor (VSS) 'A' Range/Performance. Check circuit continuity and ground-side voltage drop (< 0.05 V) for Vehicle Speed Sensor (VSS) 'A' Range/Performance. Inspect the reluctor target and sensor mounting for radial runout, wobble, or incorrect air gap. Mechanic tip: If the Hall signal is stuck at 5V or 0V while rotating, unplug the sensor and probe the signal wire to ECM: seeing 5V pull-up confirms harness and ECM integrity, pinpointing a dead Hall IC.

Standard EOBD

P0501 - Hastighetssensor (VSS) 'A' – urimelig måleverdi

Q: What are the symptoms of fault code P0501?

Signal plausibility mismatch between measured reading and ECU target model Check Engine Light (MIL) illuminated Possible drivability or power reduction Risk of failing an emissions inspection

Q: What causes fault code P0501?

Most likely: Vehicle Speed Sensor (VSS) 'A' Range/Performance is electrically operational but performing outside calibrated tolerance 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 Vehicle Speed Sensor (VSS) 'A' Range/Performance Likely: Poor ground connection or excessive voltage drop (> 0.1 V) at the ground point for Vehicle Speed Sensor (VSS) 'A' Range/Performance Rare: Defective internal output driver or reference circuit in the control module for Vehicle Speed Sensor (VSS) 'A' Range/Performance

Relatert:Hastighetssensor (VSS) 'A', Ledningsnett og kontakter, Styreenhet (ECM/PCM)

System

Drivlinje (Motor og girkasse)

Kontakt oss Finn reparasjon

Teknisk beskrivelse

Styreenheten registrerer en feil i Hastighetssensor (VSS) 'A' (P0501). Signalet er elektrisk gyldig, men stemmer ikke med øvrige driftsparametere.

Multimeter Målepunkter & Nominelle Verdier

Målepunkt / Komponent	Måletype	Nominelt Målområde	Målevilkår
Hastighetssensor (VSS) 'A' – matespenning	Spenning (V)	5.0 V eller 12.0 V	Tenning PÅ
Hastighetssensor (VSS) 'A' – signal lav / høy	Spenning (V)	Lav < 0.5 V / Høy > 4.5 V	Motoren dreies sakte

Hastighetssensor (VSS) 'A' – matespenningSpenning (V)

Børverdi:5.0 V eller 12.0 V

Tenning PÅ

Hastighetssensor (VSS) 'A' – signal lav / høySpenning (V)

Børverdi:Lav < 0.5 V / Høy > 4.5 V

Motoren dreies sakte

Oscilloskop Kurveformanalyse

1 ms/div, 2 V/div

Registrer firkantsignalet under start; bratte flanker og stabile nivåer.

Mulige årsaker

Hastighetssensor (VSS) 'A' fungerer elektrisk, men yter utenfor toleranse

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

Gnagd eller klemt ledningsnett fram til Hastighetssensor (VSS) 'A'

Dårlig jordforbindelse eller spenningsfall (> 0.1 V) for Hastighetssensor (VSS) 'A'

Defekt driver eller referanseutgang i styreenheten for Hastighetssensor (VSS) 'A'

Symptomer

Urimelig avvik mellom målt signal og beregnet referanse

Motorlampe (MIL) lyser

Mulig redusert kjørbarhet eller effekt

Risiko for underkjent EU-kontroll

Anbefalt tiltak

Sammenlign måleverdier mellom krets A og krets B.

Logg livedata under ulik belastning og sammenlign med referanseverdier.

Sjekk matespenning og kontaktstykke ved Hastighetssensor (VSS) 'A'.

Mål kontinuitet og jordspenningsfall (< 0.05 V) for Hastighetssensor (VSS) 'A'.

Inspiser tannhjul og sensorfeste for slark og skader.

Mekanikerens tips

Hvis Hall-signalet står fast på 5V eller 0V, koble fra sensoren og sjekk 5V pull-up fra ECM for å isolere feilen til sensoren.

Relaterte feilkoder

P0551

Servostyring trykksensor/bryter – urimelig måleverdi

P0598

Thermostat varmer – styrekrets lavt signal

P0584

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P0510

Lukket gasspjeld posisjonsbryter

Målepunkt / Komponent

Måletype

Nominelt Målområde

Målevilkår

Hastighetssensor (VSS) 'A' – matespenning

Spenning (V)

5.0 V eller 12.0 V

Tenning PÅ

Hastighetssensor (VSS) 'A' – signal lav / høy

Spenning (V)

Lav < 0.5 V / Høy > 4.5 V

Motoren dreies sakte