engine scanner code P 178 means?

Asked by May 22, 2017 at 03:22 PM about the 2002 Toyota MR2 Spyder 2 Dr STD Convertible

Question type: Maintenance & Repair

1 Answer

87,285

P0178 - Fuel Composition Sensor Circuit Low Input...Possible causes: Flexible Fuel (FF) sensor to Vehicle Power (VPWR) circuit harness open or shorted, FF to VPWR circuit poor electrical connection, Open in FF sensor signal circuit, Short to ground in FF sensor signal circuit, Fuel contamination, Short to VPWR in FF sensor batte...Tech notes: Replaced Fuel Composition Sensor...Possible symptoms: Engine Light ON (or Service Engine Soon Warning Light)... P0178 Description: Fuel Composition Sensors are used to determine the amount of ethanol alcohol in the gasoline. Normally, a gasoline engine should not have more than 10% ethanol alcohol in the fuel for proper operation. Some vehicles have a Flexible Fuel (FF) system on them that allow them to run on up to 85% ethanol alcohol in the fuel. The fuel composition sensor sends a frequency modulated signal to the engine controller which is proportional to the alcohol content of the fuel. The injector pulse width and the ignition timing are modified for the increased alcohol content. It takes almost twice the amount of alcohol compared to gasoline to produce the same power.

Your Answer:

Toyota MR2 Spyder Experts

  • #1
    WheelerDealer
    Reputation
    250
  • #2
    Sisnetball
    Reputation
    200
  • #3
    Michael Kane
    Reputation
    90
View All

Related Models For Sale

Used Honda S2000
7 Great Deals out of 294 listings starting at $8,500
Used Mazda MX-5 Miata
52 Great Deals out of 3,994 listings starting at $1,995
Used Porsche Boxster
30 Great Deals out of 1,023 listings starting at $2,500
Used Chevrolet Corvette
110 Great Deals out of 14,561 listings starting at $3,900
Used Ford Mustang
387 Great Deals out of 39,640 listings starting at $1,995
Used Nissan 350Z
20 Great Deals out of 907 listings starting at $2,750
Used BMW Z4
24 Great Deals out of 806 listings starting at $3,199
Used Toyota Celica
4 Great Deals out of 254 listings starting at $2,500
Used Chevrolet Camaro
314 Great Deals out of 27,184 listings starting at $2,700
Used Porsche 911
74 Great Deals out of 4,427 listings starting at $12,495

Content submitted by Users is not endorsed by CarGurus, does not express the opinions of CarGurus, and should not be considered reviewed, screened, or approved by CarGurus. Please refer to CarGurus Terms of Use.