Particularly important information is distinguished in this manual by the following notations:

This is the safety alert symbol. It is used to alert you to potential personal injury hazards. Obey all safety messages that follow this symbol to avoid possible injury or death.
WARNING
A WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury.
NOTICE
A NOTICE indicates special precautions that must be taken to avoid damage to the vehicle or other property.
TIP
A TIP provides key information to make procedures easier or clearer.
IntroductionIntake 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"
...
Checking the diode
1. Check:
Diode
Out of specification Replace.
NOTE:
The pocket tester or the analog pocket tester
readings are shown in the following table.
a. Disconnect the diode from the wire harness.
b. Connect the pocket tester ( × 1)
to the diode
terminals as shown.
c. Check the diod ...
Checking the valve seats
The following procedure applies to all of the
valves and valve seats.
1. Eliminate:
Carbon deposits
(from the valve face and valve seat)
2. Check:
Valve seat
Pitting/wear Replace the
cylinder head.
3. Measure:
Valve seat width C "a"
Out of specification Replace
the ...