Yamaha YZF-R125 Service Manual: Intake air pressure sensor

1. Check:

  • Intake air pressure sensor output voltage Out of specification Replace the throttle body.

a. Connect the pocket tester (DC 20 V) to the throttle body sensor assembly coupler as shown.


  • Positive tester probe
    pink/white "1"
  • Negative tester probe
    gray/black "2"

Intake air pressure sensor


b. Set the main switch to "ON".

c. Measure the intake air pressure sensor output voltage.

    Throttle position sensor
    1. Check: Throttle position sensor a. Connect the digital circuit tester to the terminals of the throttle body sensor assembly coupler as shown. Positive tester probe → gray/red t ...

    Intake air temperature sensor
    1. Check: Intake air temperature sensor resistance Out of specification Replace the throttle body. a. Connect the pocket tester ( × 1k) to the throttle body sensor assembly co ...

    Other materials:

    Removing the crankshaft
    1. Remove: Crankshaft "1" NOTE: Remove the crankshaft with the crankcase separating tool "2". Make sure the crankcase separating tool is centered over the crankshaft. CAUTION: To protect the end of the crankshaft, place an appropriate sized socket between the c ...

    Checking the ignition coil
    1. Check: Primary coil resistance Out of specification  Replace. a. Disconnect the ignition coil connectors from the ignition coil terminals. b. Connect the pocket tester ( × 1) to the ignition coil as shown. Positive tester probe red/white "1" Negative tester probe orange ...

    Troubleshooting
    Any of the following fail to light: headlight, high beam indicator light, taillight, license plate light, auxiliary light or meter light. NOTE: Before troubleshooting, remove the following part(s): 1. Seats 2. Fuel tank ...

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