1988 PONTIAC FIERO brake

AIR CONDITIONING: AlR DELIVERY
660, MANUAL
TROUBLESHOOTING HINTS
Try the following checks before doing System
Diagnosis.
1. Cheek for manifold vacuum to the vacuum
tank at the BLACK hose from the engine and
at the VIOLET hose to the
A/C Control
Head.
2. Check the operation of the Temperature
Valve by moving the Temperature Selector
rapidly back and forth several times. Listen
for the valve to strike the stop at each end of
its travel.
If the sound indicates that the
valve is not fully closing or opening, check
the mechanical linkage between the valve
and the Temperature Selector.
3. Check that Heater Water Bypass Valve
operates when Temperature Selector is
moved to maximum cold position.
Go to the AlC System Check in 8A-62 for a
guide to normal operation and diagnostic ref-
erences for the entire
AIC System.
r Go to Systern Diagnosis to isolate air delivery
conditions.
SYSTEM DIAGNOSIS
Engine vvarm and running at idle.
If air flow does not come from the proper
outlets under one or more operating modes,
at least one of the air valves is not moving to
the proper position.
Check the operation of the air valves using
the following chart. Put Blower Switch in
HI
to give a strong flow of air.
COMPONENT LOGATlORl Page-Figure
Check Valve.
. . . . . . . . . . . . . . . . . . . . Behind engine, to right of master brake cylinder . 201-15-A
HeatIDefrost Vacuum Actuator . . . . Behind IIP, on LN side of plenum . . . . . . . . . . . . . 201-14-6
Lower Mode Vacuum Actuator
. . . . . Behind I/P, on LH lower side of plenum . . . . . . . . 201-14-C
Recirculating-Outside Air Vacuurn
Actuator (Manual) . . . . . . . . . . . . . . Behind IIP, on RH side of plenum. . . . . . . . . . . . . 201-14-6
Upper Mode Vacuum Actuator
. . . . . Behind I/P, on LN side of plenum . . . . . . . . . . . . . 201-14-6
Vacuum Tank
. . . . . . . . . . . . . . . . . . . Lower LIH front corner of engine compartment . . 201-15-A
AIR VALVE POSlTlON TABLE * Additional tests of the Ale Vacuum System
are given in Section
1 B.
GIWCUiT OPEMTIOIU
The air valves in the air conditioning system
are operated by mechanical and vacuum con-
trols. There are no electrical circuits. The func-
tions of the air valves and
A/C Evaporator Core
are described below.
Temperature Valve
The Temperature Valve is mechanically
linked to the temperature selector in the
AIC
Control Head. With the selector in Cold, the
valve is in the cold position. This prevents air
from blowing across the Heater Core. With the
selector in any other position, some or
all of the
air blows across the Heater Core providing con-
tinuous temperature control.
(Continued on next page)

AIR CONDITIONING: COMPRESSOR CONTROLS
C67. ELECTRONIC
TROUBLESHOOTING HINTS
Try the following checks before doing the
System Check
.
1 . Check CLSTR Fuse by visual inspection .
2 . Check that the A/C Compressor Clutch con-
nector is firmly seated
.
3 . Check that ground 6112 is clean and tight .
Go to System Check for a guide to normal
Compressor Control operation
.
o Go to System Diagnosis for Compressor Con-
trol diagnostic tests
.
SYSTEM CHECK
Complete the AIC System Check in Section
$A-62 as a guide to normal operation of the
AIC System .
Use the sy&esla Check Table as a guide to
normal operation
of the Compressor Control .
COMPONENT LOCATION Page-Figure
.... ..................... A/C Compressor Clutch (VIN E) Top
RH front of engine 201-
4-A
AIC Compressor Clutch (VIN F) (VIN
..................... ............................ 8) Top RN front of engine 201- 6-A
.... ...................... A/C Compressor Clutch (VIN S) Top LH front of engine 201-
0-B
A/C Compressor Control Relay ..... LN rear comer of engine compartment. on relay
................................. bracket 201- 0-A
Ale High Pressure Cut-Out Switch
(VIN E)
....................... Top RH front of engine. on rear of AIC
.............................. compressor 201- 4-D
AIC High Pressure Cut-Out Switch
(VIN F) (VIN 8)
................. Top RN front of engine. on rear of AlC
.............................. compressor 201- 6-C
A/C Nigh Pressure Cut-Out Switch
(VIN S)
....................... Top LH front of engine. on rear of AIC
.............................. coqressor 201- 0-B
Diode
.......................... Inside AIC Compressor Clutch connector ....... 201- 0-B
Electronic Control Module
(ECM) ... Behind RH side of I/P ...................... 201-12-B
Fuse Block
...................... Behind LH side of IIP. below light switch ....... 201-10-A
Power Steering Switch
............ Lower LH front comer of engine compartment.
.......................... on steering unit 201- 0-A
Pressure Cycling Switch
........... On side of Ale accumulator .................. 201-14-A
ClOO (42 cavities) ................ LN front of dash. left of brake master cylinder .. 201- 0-A
6102 (4 cavities) ................. Center front of dash ........................ 201-14-A
6215 (3 cavities) ................. Center of I/P. behind AlC control ............. 201-14-B
6112 (VIN E)
................... Rear of LH cylinder head .................... 201- 3-C
6112 (VIN F) (VIN 8)
............. Rear of LH cylinder head .................... 201- 7-6
6112 (VIN S) .................... Rear of LH cylinder head .................... 201- 0-C
6118 (VIN S)
.................... Rear of RH cylinder head .................... 201- 1-6
S111 ........................... Engine harness. RH rear of engine compartment 201-
1-A
S117 (VIN
F) (VIN 8) ............. Engine harness. top center rear of engine ....... 201- 7-A
S120
........................... Engine harness. RIP front of dash ............. 201- 2-A
S143 (VIN S)
.................... Engine harness. center front of dash ........... 201- 1-A
S175 (VIN S)
.................... Engine harness. lower LH front of dash ........ 201- 0-A
S177
........................... Engine harness. top RH front of engine ........ 201- 5-A
S201
........................... IIP harness. behind instrument cluster ......... 201-10-A
S204
........................... I/P harness. behind instrument cluster ......... 201-10-A

AIR CONDITIONING: AIR DELIVERY I g
667, ELECTRONIC
TROUBLESHOOTING
HINTS
Try the following checks before doing System
Diagnosis.
1. Check for vacuum to the vacuum tank at the
BLACK Hose from the engine vacuum
source and at the VIOLET Rose to the
AIC
Vacuum Solenoid Module.
Check the operation of the Temperature
Valve by setting the Temperature Selector
to COLD and then moving it to ROT.
Observe that the valve moves through its
full range each time the Temperature Selec-
tor is changed from one end of the range to
the other. If the valve is not fully closing or
opening, check that the valve is free to move
and that none of the linkage is binding.
3. Check that Heater Water Bypass Valve
operates in MAX
AIC Mode.
Go to the AIC System Check in 8A-62 for a
guide to normal operation of the Air
Delvery
System.
Go to System Diagnosis
in this section for
diagnostic tests.
SYSTEM DIAGNOSIS
Engine warm and running at idle.
If air flow does not come from the proper
outlets under one or more operating modes,
at least one of the air valves is not moving to
the proper position.
@ Check the operation of the air valves using
the following chart. Put Blower switch in
HI
to give a strong flow of air.
COMPONENT LOCATION Page-Figure
AIC Defrost Vacuum Actuator ..... Behind IIP, on LH side of plenum .............
AIC Temperature Door Motor ...... Behind IIP, on RH side of plenum. ............
AIC Vacuum Solenoid Module ...... Behind IIP, on RH side of plenum. ............
Check Valve. .................... Behind engine, to right of master brake cylinder.
Fuse Block.
..................... Behind LH side of IIP, below light switch. ......
Neater Water Bypass Valve. ....... RH front of engine
Lower Mode Vacuum Actuator
..... Behind IIP, on LH side of plenum .............
Outside Air Vacuum Actuator. ..... Behind IIP, on RH side of plenum. ............
Upper Mode Vacuum Actuator ..... Behind IIP, on LH side of plenum .............
.. Vacuum Tank ................... Lower LH front corner of engine compartment
6200
.......................... Behind IIP, left of steering column ............
S125. .......................... Engine harness, top LH rear of engine .........
........ S201. .......................... IIP harness, behind instrument cluster.
........ S205. .......................... IIP harness, behind instrument cluster.
(Disconnected)
Condition:
IgnEon Swgch: ON
AIR DOOR POSITION TABLE A: AIC CONTROL HEAD VOLTAGE TEST
Measure
Between I Correct Vdtage / For Diagmsk I
Conditions: ignition Switch: RUN (Engine Running)
Blower Switch: HI
I"(BRNIWIFDI & Ground Battery ( See1 I
Measure: VOLTAGE
At:
A/C CONTROL HEAD CONNECTOR 61
I I
@ If voltages are correct, go to tests B and C.
(Continued on facing page)
Mdifional tests of the AIC Vacum System are
(950) wire.
2- ~hd for op in BLK (150) rrire to given in Seclion 1B.

WARNINGS AND ALARMS: CHIMES
TROUBLESHOOTING H lNTS
* Try the following checks before doing the
System Check.
1. Check the STOP HAZ Fuse by observing
the Hazard Lights Operation.
2. Check the GAGES Fuse by observing the
BRAKE Warning Indicator with the Park
Brake applied and the Ignition Switch in
RUN.
3. Check 6200 by operating the Cigar Lighter.
4. If the FASTEN BELT chime reminder and
indicator operate continuously, replace
Audio Alarm Assembly.
5. If the Park Lights are operating normally
and only the Lights-On reminder operates
incorrectly, replace the Audio Alarm Assem-
bly.
Go to System Check for a guide to normal
operation.
Go to System Diagnosis for diagnostic tests.
SYSTEM CHECK
* Use the System Check Table as a guide to
normal operation.
COMPONENT LOCATlON Page-Figure
Convenience Center
.............. Behind IIP, to right of steering column. ........ 201-10-A
Fuse Block.
..................... Behind LH side of IIP, below light switch. ...... 201-10-A
Ignition Key Warning Switch
...... Upper part of steering column
Seatbelt Switch. ................. In driver's seatbelt buckle
C210
(11 cavities) ................ Behind IIP, on RH lower side of steering column. 201-
9-A
6325 (1 cavity) .................. At LH door sill, base of center pillar
6200 .......................... Behind IIP, left of steering column ............ 201-10-A
S204. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
S205. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
S225. .......................... I/P harness, behind instrument cluster. ........ 201-10-A
S227. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
SYSTEM CHECK TABLE
ACTION
Sit in the driver's
seat and close the
driver's door
Turn the Ignition
Switch to RUN
Do not buckle the
seatbelt
NORMAL RESULT
A slow chime alarm
sounds
The FASTEN
BELTS Indicator
lights in the
Instrument Cluster
The chime stops and
the indicator shuts
off after 4 to
8
(Continued from previous column)
buckle
seatbelt
ignition, open the
LH front door
I seconds
(Continued in next column)
(Continued on facing page)

INSTRUMENT PANEL: GAGES CLUSTER I e
CLUSTER REAR VIEW
CONNECTOR 62
-
BULB LOCATIONS
CONNECTOR Cl
TEST POINTS CONNECTOR Cl
A Illumination TP1 Oil Pressure Gage Sender 1
B BRAKE Warning Indicator TP2 Temperature Gage Sender 2
C Not Used TP3 Fuel Gage Sender 3
D Illumination TP4 Tachometer Sender 4
E Illumination TP5 Speed 5
F SERVICE ENGINE SOON Indicator
6
G Not Used 7
H Illumination 8
I Fasten Belts Indicator 9
J Illumination 10
K Illumination 11
L RH Turn Indicator 12
M LH Turn Indicator 13
N Hi Beam Indicator 14
O Illumination
P Illumination
Q Illumination
R SHIFT Indicator Tachometer Sender
Ground
Illumination
Not Used
Temperature Gage Sender
Not Used
Open
Oil Pressure Gage Sender
Ignition
Not Used
Not Used
Ground
Fasten Belts
Speedometer
CONNECTOR 62
1 BRAKE Warning Indicator
2 Ground
3 Illumination
4 Open
5 Open
6 Open
7 LH Turn Indicator
8 Hi Beam Indicator
9 RH Turn Indicator
10 Fuel Gage Sender
11 Not Used
12
470R to Generator
13 SERVICE ENGINE SOON Indicator
14 SHIFT Indicator

INSTRUMENT PANEL: GAGES CLUSTER
TROUBLESHOOTING HINTS COMPONENT LOCATION Page-Figure
* For a list of possible symptoms, go to System Coolant Temperature Sender (VIN E) Lower LH side of engine ....................
Diangosis. Coolant Temperature Sender (VIN F)
....................... .................... * For Instrument Cluster removal and replace- (VIN 8). Lower
LH side of engine
ment procedures, see Section 8C of the Ser- Coolant Temperature Sender (VIN S) Top LN front of engine, behind A/C Compressor.
.................. ..................... vice Manual. Fuel Tank Unit Top center of fuel tank.
..................... ...... * Try the following checks before doing the Sys- Fuse Block. Behind
LH side of IIP, below light switch.
................. tem Check. Ignition Switch. Behind IIP, on
top side of steering co
....... ........... Oil Pressure Sender (VIN E) Top rear of engine, near distributor. 1. Check GAGES Fuse by observing the . ........... Oil Pressure Sender (VIN F) (VIN 8) Top
rear of engine, near distributor.
BRAKE Warning Indicator with the Igni- Oil Pressure Sender (VIN S) ........ Lower LN side of engine .................... tion Switch in RUN and the Park Brake ................ .. el00 (42 cavities) LN
front of dash, left of brake master cylinder
applied.
................. C313 (3 cavities) Below
center of back seat. ...................
2. Check ground 6200. . 6118 (VIN F) (VIN 8) ............. Rear of RN cylinder head. ...................
.................... ................... 3. Check case ground of Coolant Temperature 6118
(VIN S) Rear
of RH cylinder head.
.......................... ............ Sender. 6200 Behind I/P, left of steering column ' h .......................... 4. Check case ground of Oil Pressure Sender. 6304 Under rear seat,
on support bracket
.......................... S204. IIP harness, behind instrument cluster. ........ 5. Check Indicator bulbs. .......................... ........ S205. I/P harness, behind instrument cluster. * Go to System Check for a guide to normal .......................... S217. I/P harness, behind center of IIP .............. operation.
* Go to Systern Diagnosis for diagnostic tests.
SYSTEM CHECK
* Use the System Check Table as a guide to
normal operation. Refer to the diagnosis given
if other results occur.
* Tests follow in System Diagnosis.

INSTRUMENT PANEL: GAGES CLUSTER
I Oil Pressure Gage
(Continued from previous page)
indicates low
pressure
and oil
pressure is good
Coolant
Temperature Gage
does not indicate
HOT with Ignition
Switch in START or
BULB TEST, but
does operate
accurately
Do Test I: (Also see
Test A
terminal B)
Check DK GRN (35)
wire and Ignition
Switch for opens
Repairlreplace as
necessary
Oil Pressure Gage
indicates high
pressure at
all times
and oil pressure is
good Do
Test
J: (Also see
Test A terminal
8)
Oil Pressure Gage is
inaccurate Do
Test K: (also see
Test A terminal
8)
Do Test L
Tachometer does not
operate
Speedometer1
Odometer is
inaccurate Do
Test M
Do Test N: (with
5-33431-873 harness
connector available)
One or both
Odometers do not
operate properly,
but Speedometer
operates accurately
I
Check the
Instrument Cluster
Printed Circuit for
cracks or flaws
Replace the
Speedometer1
Odometer Assembly
(Continued in next column) (Continued from previous
column)
Hi Beam Indicator
does not operate
properly See
Exterior lights
Section 8A-110
(Also see Test
B
terminal 8)
I operate properly
I
(Also see Test A
I
Seatbelt Indicator
and alarm do not
BRAKE Warning Indicator does not
work properly
I
See Warnings and
Alarms (see Index)
SERVICE
ENGINE SOON
Indicator does not
does not work See
Brake Warning
System, Section
8A-41 (Also, see
Test A terminal
1)
See Section 6E of
1 Service Manual
Do Test O
r
(Also, see Test B
terminals 7 and
9)

-. INSTRUMENT PANEL: DIGlTAL CLUSTER
INDICATORS
STARTER AND
CHARGING
SYSTEM (CHARGING) MULTIPORT FUEL BRAKE
INJECTION (V6 WIN S,V8 VIM 8) WARNING
TUNED PORT SYSTEM
INJECTION
(V8 VIN F) THROTTLE BODY
INJECTION (V8 WIN E)