Fault code lookup

PowertrainP0494

Caution

Severity: Caution - get it checked when you can

Fan 1 Underspeed

28 brands affected · Generic SAE J2012 description.

Key terms: Catalytic converter: cleans the exhaust gases · EGR: exhaust gas recirculation, which cuts harmful gases · EVAP: the system that traps fuel vapour · Oxygen sensor: measures oxygen in the exhaust gas · SAE J2012: the standard generic code list · Powertrain: engine, transmission and emissions

1What it means in plain English

This range covers emissions control (EGR, EVAP, oxygen sensors and the catalytic converter), but some manufacturers also use P04 codes for oil-pressure, brake-fluid and coolant-level warnings.

2Common causes

  1. Clogged or faulty EGR valve
  2. EVAP system leak (hoses, canister, fuel cap)
  3. Faulty oxygen sensor
  4. Ageing catalytic converter
  5. Low oil, brake fluid or coolant (on some models)
  6. Wiring or connector fault

3Can I drive?

Caution · drive with care

Do not assume this code is safe to drive. Check the description: if it names oil pressure, brake fluid, coolant, or a brake fault, stop safely and have it diagnosed before driving. Emissions-only codes (EGR, EVAP, catalyst) should still be checked before an emissions or roadworthiness inspection.

This page gives general information. It is not professional advice. For a definite diagnosis and a repair quote, ask a qualified mechanic to inspect the car.

4Brand data 28

BrandCodeDescriptionSystem
Ashok Leyland CVP0494Fan 1 Underspeed SAEPowertrain
BAIC MotorP0494Fan Speed Low BrandPowertrain
BYDP0494Fan Speed Low BrandPowertrain
CheryP0494Fan Speed Low BrandPowertrain
DaewooP0494Fan Speed Low BrandPowertrain
DFFSP0494Fan Speed Low BrandPowertrain
DFFXP0494Fan Speed Low BrandPowertrain
DFXKP0494Fan Speed Low BrandPowertrain
EOBDP0494Fan 1 underspeed BrandPowertrain
GeelyP0494Fan Speed Low BrandPowertrain
GMP0494Fan 1 Underspeed SAEPowertrain
Great WallP0494Fan Speed Low BrandPowertrain
HafeiP0494Fan Speed Low BrandPowertrain
HoldenP0494Cooling Fan System Performance BrandPowertrain
HyundaiP0494Fan 1 Underspeed SAEPowertrain
IsuzuP0494Fan 1 Underspeed SAEPowertrain
Land RoverP0494Fan 1 Underspeed SAEPowertrain
MitsubishiP0494Fan control BrandPowertrain
OpelP0494Fan Speed Low BrandPowertrain
PeugeotP0494Fan 1 Underspeed SAEPowertrain
PorscheP0494Kühlerlüfter schwergängig BrandPowertrain
ProtonP0494Fan control BrandPowertrain
SaabP0494Fan Speed Low BrandPowertrain
MG (SAIC)P0494Fan Speed Low BrandPowertrain
SuzukiP0494Fan speed low BrandPowertrain
TataP0494Fan Speed Low BrandPowertrain
ToyotaP0494Cooling fan diagnostic input, low speed BrandPowertrain
VolkswagenP0494SAE: Fan Speed Low BrandPowertrain

Legend: SAE is the generic J2012 description; Brand is text taken from that manufacturer’s data. Manufacturer rows keep the wording and language of the source data, and non-English text is tagged so screen readers pronounce it correctly.

5Related codes

  • P0490 EGR A Control Circuit High
  • P0491 AIR System Insufficient Flow (Bank 1)
  • P0492 AIR System Insufficient Flow (Bank 2)
  • P0493 Fan Overspeed
  • P0495 Fan 1 Overspeed
  • P0496 EVAP System High Purge Flow
  • P0497 EVAP System Low Purge Flow
  • P0498 EVAP System Vent Valve Control Circuit Low
  • P0499 EVAP System Vent Valve Control Circuit High
  • P049A EGR 'B' flow
  • P049B EGR 'B' flow insufficient detected
  • P049C EGR 'B' flow excessive detected

Browse Pxxx codes or P049xx codes.

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