Pontiac Fiero 1988 Service Manual page 445

6E-18 DRIVEABILITY AND fcMISSIONS - FUEL INJECTION
HIGH IMPEDANCE MULTIMETER
(DIGITAL VOLTMETER-DVM)
J34029-A
VOLTMETER - Voltaqe Position Measures amount of
voltage. When connected in parallel to an existing
circuit. A d i g i t a l voltmeter with 10 meg ohm input
impedence is used b e c a u s e this type of meter will
not load down the circuit and result in faulty
readings.some circuits require accurate low voltage
readings, and some circuits in the ECM have a very
high r e s i s t a n c e .
AMMETER - When used as ammeter, this meter also
accurately measures extremely low current flow.
Refer to meter instructions for more information.
• Selector must be set properly for both function
and range. DC is used for most automotive
measurements.
OHMMETER - Measures resistance of circuit directly
in ohms. Refer to meter for more information.
• OL Display in all ranges indicates open circuit
• Zero display in all ranges indicates a short
circuit.
• Intermittent connection in circuit may be
indicated by digital r e a d i n g t h a t will not
stabilize on circuit.
e Range Switch.
r™]200n
- Reads ohms directly
^ 2 K , 2 0 K , 2 0 0 K Q
- Reads ohms in thousands
2M and 20MQ - Reads ohms in millions
J23738
VACUUM PUMP (20 IN. HG. MINIMUM)
Use gage
t o m o n i t o r
manifold
engine
vacuum and the
hand
p u m p to
check
v a c u u m
sensors,
s o l e n o i d s
and
valves.
^ J34142-A
UNPOWERE© TEST L3(3HT
Used to check wiring for complete circuit and short to
ground or voltage.
TACHOMETER
Use inductive trigger signal
p i c k u p
type to check RPM.
5-2-86
*7S 3382-6E