1988 PONTIAC FIERO Service Repair Manual

-. COOLANT FAN: V6 VIN S $
I

COOLANT FAN: V8 VIN F, V8 VIN 8
DIAGNOSTIC LINK (ALDL) CONNECTOR SEE COOLANT FAN:
V8 VIN F V8 VIN 8 (AUXILIARY)
SEE GROUND PRESSURE EXCEEDS
DISTRIBUTION
233 PSI (1600 ItPa)
VEHICLE

" COOLANT FAN: V8 VIN F, V8 VIN 8
AUXILIARY COOLANT FAN
.8 GRY .8 BLK
CLOSED WHEN
CLOSED ABOVE
EXCEEDS
233 PSI 114' C (238' F)
- - - -

- COOLANT FAN: V8 VIN E
FUSIBLE - LINK H -
FUSE - BLOCK -
STARTER AN0 CHARGING
1 250 SYSTEM CHARGING .B BRN 1250
COOLANT
FAN SE CLOSES ABOVE llOo C (23S0 F) IEGROUND COMANT QlSTRlEUTlQN TEMPERATURE
- -

COOLANT FAN I g
TROUBLESHOOTING HINTS
@ Try the following checks before doing the Sys-
tem Check.
1. Check the CIH-FAN Fuse if the Coolant Fan
does not run.
2. Check that ground 6112 (V6 VIN S), 6117
(V8 VIN E) or 6104 (V8 VIN F and V8 VIN
8) is clean and tight.
3. Check the Fusible Link (see schematic).
4.
If the Coolant Fan runs with the Ignition
Switch OFF, replace the Coolant Fan Relay.
@ Go to System Check for a guide to normal
operation.
Go to System Diagnosis for diagnostic tests.
SYSTEM CHECK
Use the System Checlc Table as a guide to
normal operation.
SYSTEM CHECK TABLE
I ACTION I NORMALRESULT 1
COMPONENT LOCATION Page-Figure
Assembly Line Diagnostic Link
(ALDL) Connector .............. On bottom of IIP hush panel, to right of steering
column
Auxiliary Coolant Fan Relay
....... RH front side of engine compartment. ......... 201- 5-A
Auxiliary Coolant Fan Switch
...... Lower RN rear of engine .................... 201- 6-A
Coolant Fan Relay (VIN
E). ........ LH rear corner of engine compartment, on relay
bracket
................................. 201- 3-A
Coolant Fan Relay (VIN F) (VIN 8)
. . Front of engine compartment, RN side of
radiator support.
......................... 201- 5-A
Coolant Fan Relay (VIN S)
......... LH rear corner of engine compartment, on relay
................................. bracket 201- 0-A
Coolant Fan Switch
.............. Lower RH rear of engine, above starter solenoid . 201- 4-A
Coolant Temperature Sensor (VIN F)
(VIN 8).
....................... Top LW front of engine. ..................... 201- 8-C
Coolant Temperature Sensor (VIN S) Top LH front of intake manifold.
............. 201- 0-A
Electronic Control Module (ECM)
... Behind RN side of IIP ...................... 201-12-B
Fan Pressure Switch (VIN F) (VIN 8) Lower RH side of engine, on
AIC line .......... 201- 5-A
Fan Pressure Switch (VIN S)
....... Lower RN front of engine compartment, on AIC
line .................................... 201- 1-A
Fuse Block.
..................... Behind LN side of IIP, below light switch. ...... 201-10-A
Fusible Link
N (VIN E) ........... RH front of engine compartment, at Junction
Block ................................... 201- 3-B
Fusible Link N (VIN F) (VIN 8).
.... LN front of engine compartment, behind battery 201- 5-C
Fusible Link
J (VIN S) ............ RN side of radiator support, at Junction Block .. 201- 1-A
Redundant Cooling Fan Switch.
.... Top RW rear of engine ...................... 201- 1-6
C102 (4 cavities) ................. Center front of dash. ....................... 201-14-A
6104 (6 cavities)
................. Front of engine compartment, RH side of
................................ radiator. 201- 5-A
C204 (4 cavities) ................. Above LH rear corner of engine .............. 201- 0-A
C207 (15 cavities)
................ Behind RH side of IIP, near ECM ............. ,201-13-A
C224 (6 cavities) ................. Center of IIP, behind AIC control ............. 201-14-B
6104
.......................... On radiator support, behind RN headlights. .... 201-16-A
6112 (VIN E)
................... Rear of LN cylinder head. ................... 201- 3-C
6112 (VIN S)
.................... Rear of LH cylinder head. ................... 201- 0-C
6118 (VIN F) (VIN 8)
............. Rear of RH cylinder head. ................... 201- 5-A
6118 (VIN S)
.................... Rear of RH cylinder head. ................... 201- 1-C
(Continued on next page)
With
the engine cold
and idling, turn the
AIC Selector to
NORM (if equipped
with Ale)
VIN E: Coolant Fan
turns on
VIN S, VIN
F &
VIN 8: Coolant Fan
(and Auxiliary
Coolant Fan-if
equipped) turns on
when
A/C Control
Head Pressure
exceeds 233 psi
(1600
kPa)
(Continued on next page)

COOLANT FAN
With the engine
warm, run the
engine at a fast idle
for several minutes
(Continued
from previous page)
Switch to off
With
the engine
coolant below
operating
temperature, move
the AlC Selector to
OFF
Coolant Fan (and
Auxiliary Coolant
Fan-if equipped)
turns on before the
Coolant
Temperature
Indicator in the
Instrument Panel
lights or before the
Coolant
Temperature Gage
needle indicates hot
Coolant Fan (and
Auxiliary Coolant
Fan-if equipped)
turns off
VIN E:
Coolant Fan
turns off
VIN S, VIN F
&
VIN 8: coolant Fan
(and ~~~ili~~~
Coolant Fan-if
equipped) turns off
when
A/C Control
Head Pressure falls
below 233 psi (1600
kPa)
- -
* Refer to System Diagnosis when a result is not
normal.
SYSTEM DIAGNOSIS
V6 VIN S
* Do the tests listed for your symptom in the
Symptom Table below.
@ Tests follow the Symptom Table.
COMPONENT LOCATION Page-Figure
.......................... ............ 6-200 Behind IIP, left of steering column 201-10-A
....... .................... S104 (VIN S) Engine harness,
lower RN side of engine 201- l-A
....... .......................... S108. Engine harness, lower RN side of engine .201- 5-A
........................... S111 Engine harness, RR rear of engine compartment 201- l-A
.......................... S126. Engine harness, RR rear corner of engine
............................ compartment 201- 5-A
.......................... ............ S127. Engine harness, RH front of dash. 201- 2-A
.......................... S128. Cooling Fan harness, RN front corner of engine
............................ compartment 201- 6-A
.................... S142 (VIN S) Engine harness, lower RR side of engine ....... 201- l-A
............ S143 (VIN F) (VIN 8) ............. Engine harness, RH front of dash. 201- 6-A
.................... S143 (VIN S) Engine
harness, center front of dash. .......... 201- l-A
.......................... S158. Engine harness, behind RH side of IIP
.......................... S205. I/P harness, behind instrument cluster. ........ 201-10-A
S206 (VIN E)
.................... Engine harness, RH front of dash. ............ 201- 2-A
S206 (VIN
F)(VIN 8). ............. Engine harness, top center rear of engine. ...... 201- 7-A
.................... S206 (VIN S) Engine harness, above rear of engine .......... 201- 1-A
SYMPTOM TABLE
all times with the
engine cool and the
SYMPTOM
Coolant Fan does
not
run at all
Coolant Fan does
not run with engine
hot but does
run
with the A/C on
(Continued on next page)
FOR DIAGNOSIS
Do Test A
Do Test B

COOLANT FAN 1:
0 If the result is correct, go to section 6E for
ECM diagnosis.
1. Go to Table 2
A: COOLANT FAN OPEN TEST
(TABLE
1 )
Connect: FUSED JUMPER
At: ALDL CONNECTOR
Condition:
@ lgnition Switch: RUN
A: COOLANT FAN OPEN TEST
(TABLE
2)
At: COOLANT FAN RELAY CONNECTOR
(Connected)
Condition:
0 lgnition Switch: RUN
Connect
Between
B & Ground
Jumper Correct Result For Diagnosis
Between
(DK GRN/ Coolant Fan
WHT) & See 1
1 Ground 1 runs 1 1
Correct Result
Coolant Fan
runs
If the Coolant Fan runs, check the DK
GRNIWNT (335) wire for an open. If the
wire is OK, go to section 6E for ECM
diagnosis.
1. Go to Table 3.
For Diagnosis
See 1
A: COOLANT FAN OPEN TEST
(TABLE
3)
Connect: TEST LAMP
At: COOLANT FAN RELAY CONNECTOR
(Disconnected)
Condition:
0 lgnition Switch: RUN
Connect Correct Result For Diagnosis
Between
lights
0 If the results are correct, go to Table 4.
1. Check CIN-FAN Fuse and BRN (250) wire
for open.
2. Check Fusible Link J and RED (2) wire for
opens.
A: COOLANT FAN OPEN TEST
(TABLE
4)
Connect: FUSED JUMPER
At: COOLANT FAN RELAY CONNECTOR
(Disconnected)
Jumper Correct Result For Diagnosis
Between
(BLKIRED)
If the Coolant Fan runs, replace the
Coolant Fan Relay.
1. Leave fused jumper in place and go to
I Table 5.
A: COOLANT FAN OPEN TEST
(TABLE
5)
B: COOLANT FAN SWITCH TEST
Connect: TEST LAMP
At: COOLANT FAN CONNECTOR
(Disconnected)
Condition:
Fused jumper from Table
4 connected
Connect
Between
B (BLKIRED)
& Ground
B (BLKIRED)
& A (BLK)
Connect: FUSED JUMPER
At; REDUNDANT COOLING FAN
SWITCH
CONNECTOR (Disconnected)
Condition:
@ lgnition Switch: RUN
If the results are correct, replace the
Coolant Fan.
1. Check BLKIRED (532) wire for an open.
2. Check BLK (150) wire for an open.
Correct Result
Test Lamp
lights
Test Lamp lights
Jumper
Between
WHT &
Ground
For Diagnosis
See 1
See 2
@ If the Coolant Fan runs, replace the
Redundant Cooling Fan Switch, then
refer to Section 6E for ECM diagnosis.
1. Check the DK GRNIWNT (335) wire for
an open (see schematic).
Correct Result
Coolant Fan
runs
For Diagnosis
See 1

COOLANT FAN rn
6: COOLANT FAN SHORT TEST
1. With the Ignition Switch in RUN, remove
the Redundant Cooling Fan Switch connec-
tor.
If the Coolant Fan does not turn off, go to
Step
2.
If the Coolant Fan turns off, replace the
Redundant Cooling Fan Switch.
2. Remove the CIR-FAN Fuse.
If the Coolant Fan turns off, check the DK
GRNIWHT
(335) wires for a short to ground.
Refer to Section 6E for ECM diagnosis if the
wires are OK.
a If the Coolant Fan does not turn off, replace
the Coolant Fan Relay.
SYSTEM DlAGNOSlS
V8 VIN F AND V8 VIN 8
Do the tests listed for your symptom in the
Symptom Table below.
Tests follow the Symptom Table.
SYMPTOM TABLE
I SYMPTOM I FORDIAGNOSIS I
I Do Test A I
I not run at aB I I
Coolant Fan runs at
all times with the
A/C off and engine
cool
(Continued in next column)
Do
Test
B
Auxiliary Coolant
Fan does not run at
all
:Continued from previous column)
Fan runs at
all times
with
AIC off and the
Do Test C (Continued
from previous column)
GRNIWNT
(335) wire for an open. If wire
is OK, go to Section 6E for ECM diag-
nosis.
1. Go to Table 3.
A: COOLANT FAN OPEN TEST
(TABLE
1)
At: ALDL CONNECTOR
Condition:
I B &Ground I I See l' I
Connect
Between
If the result is correct, go to Section 6E
for ECM diagnosis.
A: COOLANT FAN OPEN TEST (TABLE
2)
Correct Result
I
Connect: FUSED JUMPER
At: COOLANT FAN RELAY CONNECTOR For
Diagnosis
(Connected)
Condition: lgnition Switch: RUN
Jumper
I Correct Result I For Diagnosis I Between
(DK GRN1 Coolant Fan
WHT) & See 1
1 Ground 1 runs 1 1
A: COOLANT FAN OPEN TEST (TABLE
3) I
Connect: TEST LAMP
At: COOLANT FAN RELAY CONNECTOR
(Disconnected)
Condition:
Connect I Correct Rewn I For Diagnosis I I Between
C (BRN) &
Ground
If the results are correct, go to Table
4.
1. Check CIH-FAN Fuse and BRN (250) wire
for opens.
2. Check Fusible Link H and ORN (440) wire
for opens.
E (ORN)
&
Ground
(Continued in next column)
(Continued on next page)
Test Lamp
lights See
1
Test
Lamp
lights See 2