Pontiac Fiero 1988 Service Manual page 1088

INSTRUMENT PANEL: INDICATORS C L U S T E R [
• If the voltage reading on the' test voltmeter
is different from the car's Voltmeter, check
the Voltmeter Gage connections and the
PNK/BLK (39) wire for an open. If both are
OK, repair/replace the Voltmeter (see Sec-
tion 8C).
P: TACHOMETER TEST
Disconnect the Ignition Coil connector (VIN 9)
or the Direct Ignition System connector (VIN
R). Connect the J-33431 Instrument Panel
Tester to the Ignition Coil connector (VIN 9) or
Direct Ignition System connector (VIN R)
using the J-33431-4 or J-33431-10 harness con-
nector. Connect the tester ground lead to a
known good ground. Plug the tester into an
outlet and put the Ignition Switch in RUN.
Turn the tester on and set the speed signal
switch to 54 mph.
• If the Tachometer reads 1350 rpm (VIN 9)
1800 (VIN R), check the Ignition Coil con-
nector (VIN 9) or Direct Ignition System
connector (VIN R). It should be clean and
tight.
• If the Tachometer does not read correctly,
check the WHT (121) wire for an open. If OK,
replace the Tachometer (see Section 8C).
O. AJAR INDICATOR IS
A L W A Y S
ON
With the Ignition switch in RUN disconnect
the Trunk Ajar Switch, Hood Ajar Switch, LH
Door Ajar Switch and RH Door Ajar Switch
connectors one at a time (see schematic).
• If the AJAR Indicator goes out replace the
Switch at fault.
• If the A J AR Indicator is still lit with all four
wires disconnected, check the DK GRN
(146), BLK/PNK (158), and BLK/ORN (158)
wires and Instrument Cluster Printed Cir-
cuit for a short to ground.
R: AJAR INDICATOR DOES NOT
LIGHT FOR ONLY ONE INPUT
Disconnect the suspect door, trunk, or Hood
Ajar Switch connector. Jumper the connector
wire to ground and put the Ignition Switch in
RUN.
• If the Indicator lights, check the BLK (150)
wire for an open (except Hood Ajar Switch
connector). If OK, replace the suspect
Switch.
• If the Indicator does not light, check the
suspect wire for an open (see schematic).
S: UPSHIFT INDICATOR WIRE T E S T
Disconnect ECM connector C2. Put the Igni-
tion Switch in RUN and measure the voltage at
terminal 7 (Electronic Fuel Injection), terminal
A7 (Multi-port Fuel Injection) (see Section
8A-20).
• If battery voltage is present, see section 6E
for ECM diagnosis.
• If battery voltage is not present, check the
TAN/BLK (456) wire for an open.
T: INACCURATE SPEEDOMETER AND
ODOMETER TEST
Remove the connector to the Vehicle Speed Sen-
sor. Plug the mating connector from the
J-33431 I/P tester into the Vehicle Speed Sen-
sor connector harness. With the tester set to
"ON", "54 mph" and "60 Hz" and the Ignition
Switch in RUN: the Speedometer should read
54 mph ±2 mph.
• If the Speedometer reads correctly, replace
the Vehicle Speed Sensor.
• If the Speedometer reads incorrectly, check
the PPL/WHT (401) and YEL (400) wires for
high resistance. If the wires are OK, replace
the Speedometer assembly.
U: ODOMETERfS) ARE NOT
ACCURATE
Remove the Instrument Cluster. See Section
8C of the Service Manual for Cluster Removal.
Disassemble the cluster and remove the small
Odometer connectors from the Speedometer
circuit board. Connect I/P tester J-33431-3.
Plug in the I/P tester and set it to ON, 54 mph,
and 60 Hz. With the Odometer test switch held
down, the Odometer should turn and change
the mileage shown, about 1.8 miles per minute.
• If the Odometer does not turn, replace the
stepper motor (see Section 8C).
• If the Odometer turns about 2.9 miles per
minute, a metric Odometer could have been
installed. Check to see that the correct
Odometer assembly was installed (see Sec-
tion 8C).
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