1988 PONTIAC FIERO brake

HEADLIGHTS WITH LAMP MONITOR
TROUBLESHOOTING HINTS
r Try the following checks before doing the
System Diagnosis.
1. If the Headlight on one side is dimly lit, check
the ground on that side.
2. If the Hi Beam Indicator does not light, but
the High Beams operate, check the LT GRN
(11) wire for an open (see schematic).
3. If one Headlight doesn't work, check the con-
nections, the Headlight, and the wires to the
Headlight.
4. If the Headlights do not turn off, replace the
Light Switch.
Go to the System Diagnosis for diagnostic
tests.
SYSTEM DIAGNOSIS
0 Do the Tests listed for your Symptom in the
Symptom Table below.
@ Tests follow the Symptom Table.
SYMPTOM TABLE
I SYMPTOM I FOR DIAGNOSIS I
All Headlights
inoperative or
intermittent Do
Test A
Beam Indicator are
(Continued in next column)
COMPONENT LOCATION Page-Figure
Headlight Dimmer Switch.
........ Behind IIP, on LH upper side of steering column. 201-
9-A
Lights Monitoring Module.
........ Behind IIP, at base of steering column
.. el00 (42 cavities) ................ LH front of dash, left of brake master cylinder
201- 0-A
.... 6103 (Except VIN E) ............. On radiator support, behind LH headlights.
201-16-A
.... 6104 .......................... On radiator support, behind RH headlights.
201-16-A
............ 6200 .......................... Behind IIP, left of steering column
201-10-A
.... S107. .......................... Front lights harness, behind LH headlights.
201-16-A
.... S110. .......................... Front lights harness, behind RH headlights
201-16-A
S151. .......................... Front lights harness, lower LH side of engine
compartment
............................ 201-16-A
........ S205. .......................... IIP harness, behind instrument cluster. 201-10-A
............ S230. .......................... IIP harness, behind LH side of IIP 201-10-A
............... S231. .......................... IIP harness, above Fuse Block. 201-10-A
(Continued from previous column)
A Headlight is out,
but no warning
message is displayed
on the Instrument
Panel
A: LIGHT SWITCH TEST (TABLE 1)
At: LIGHT SWITCH CONNECTOR
(Connected)
Condition: Light Switch: HEAD
Refer to Driver
Information Center
(DIC), page 86-0
A Headlight out
warning message is
displayed but all
Headlights are
functioning properly For Diagnosis
Connect
Correct Result Of Incorrect
1 Between 1 1 Results 1
Refer to Driver
Information Center
(DIG), page 86-0
I Ground (RED) I Te;ik,",mp I see 1 I
If both results are correct, go to Test B.
1. Check Fusible Link A and RED (2) wire for
an open.
D (YEL) &
Ground Test Lamp
lights Go to able

HEADLIGHTS WlTH LAMP MONITOR: FOG LIGHTS
TROUBLESHOOTING MINTS
0 Try the following checks before doing the
System Diagnosis.
1. Check that the Headlights and Park Lights
work properly before troubleshooting the Fog
Lights.
2. If one Fog Light doesn't work, check the Fog
Light, connections, and wires to the Fog
Light.
3. If the Fog Light Switch is not illu
when the Park Lights are on, check the
GRU
(8) wire.
4.
If the FOG LIGHTS ON Light and the
Panel Light do not operate, check the BLK
(150) wire for an open.
Go to System Diagnosis for diagnostic tests.
SYSTEM DIAGNOSIS
Do the test below if the Fog Lights do not
operate.
FOG LIGHTS DO NClT OPEWTE
Measure: VOLTAGE
At: FOG
LIGHT RELAY CONNECTOR
(Disconnected)
Conditions:
r Light Switch: PARK
Fog Light Switch:
ON
Measure Correct
For Diagnosis
Belvveen
COMPONENT LOCATION Page-Figure
................. Fog Light Relay LH front
of engine compartment, on fender. .... 201-16-A
..................... Fuse Block. Behind
LH side of IIP, below light switch. ...... 201-10-A
Fusible Link A (VIN
E) ........... Lower RN side of engine, at Starter Solenoid. ... 201- 2-A
Fusible Link A (VIN F) (VIN 8)
..... Lower RH side of engine, at Starter Solenoid. ... 201- 6-B
Fusible Link A (VIN S). ........... Lower RH side of engine, at Starter Solenoid. ... 201- 1-A
.................. Fusible Link D Front lights harness, near LH side of dash. ..... 201-16-A
.................. Fusible Link E. Front lights harness, near LH side of dash. ..... 201-16-A
.................. Fusible Link G Front
lights harness, near LK side of dash. ..... 201-16-A
................. Remote Dimmer RH side of steering column, on IIP retainer ..... 201-10-A
................ el00 (42 cavities) LH front
of dash, left of brake master cylinder .. 201- 0-A
.................. 6103 (1 cavity). In
front lights harness, LH rear corner of engine
.......................... compartment.. 201-15-C
................. 6213 (3 cavities) Behind LH side
of IIP, near light switch. ....... 201-10-C
6103 (Except VIN E) ............. On radiator support, behind LK headlights. .... 201-16-A
.......................... 6104 On radiator support, behind RH headlights. .... 201-16-A
.......................... ............ 6200 Behind IIP, left of steering column 201-10-A
.......................... S105. Front lights harness, behind LH headlights. .... 201-16-A
.......................... S107. Front lights harness, behind LH headlights. .... 201-16-A
.......................... S110. Front lights harness, behind RH headlights .... 201-16-A
S165. .......................... Forward lights harness, LH front comer of
...................... engine compartment 201-15-B
.......................... S204. I/P harness, behind instrument cluster. ........ 201-10-A
.......................... S225. I/P harness, behind instrument cluster. ........ 201-10-A
.......................... ............... S236. IIP harness, below light switch 201-10-A
(BRNIWNT)
& Ground
(FOG LIGHTS DO
NOT OPERATE continued
on next page)
Battery
See
1

EXTERIOR LIGHTS: TURNIHAZARDISTOP I
FROM C210, PIN M
PAGE 110-0 FROM BRAKE SWITCH PAGE 110-0 FROM C210, PIN N PAGE 110-0

TROUBLESHOOTING HINTS
Try the following checks before doing the
System Diagnosis.
Turn Lights
1. Check the TURN B/U Fuse by operating the
Back Up Lights.
2. If the Turn Indicator and Front Turn Light on
one side are inoperative, check the connection
at
C210. Replace the Turn-Hazard Switch as
necessary.
3. If only some of the Turn Lights work but all of
the Hazard Lights work, replace the
Turn-
Hazard Switch.
4. If the Turn Lights stay on (do not flash) in both
Turn Left and Turn Right, replace the Turn
Flasher.
5. If only one light does not light, check the bulb,
socket, and related wiring (see schematic).
Stop Lights
1. Check the STOP-HAZFuse by operating the
Hazard Lights.
2. If no Stop Lights work, check the Brake Switch
and ORN (140) wire for continuity (see
schematic).
3. If the Stop Lights do not turn off, adjustlre-
place the Brake Switch as necessary.
4. If only one light does not light, check the bulb,
socket, and related wiring (see schematic).
Hazard Lights
1. Check the STOP-HAZ Fuse by operating the
Stop Lights.
2. If only some of the Hazard Lights work but all
of the Turn Lights work, replace the
Turn-Haz-
ard Switch.
COMPONENT LOCATION Page-Figure
................... ..... Brake Switch. Above
brake pedal, on brake pedal support 201- 9-A
.............. ........ 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
Turn Flasher
.................... Behind IIP, to right of steering column. ........ 201- 9-A
............. TurnlHazard Switch. Top of steering column
C100 (42 cavities) ................ LH front of dash, left of brake master cylinder .. 201- 0-A
................. ................. C208 (8 cavities) Behind LH side of rear seat. 201-17-C
C210
(11 cavities) ................ Behind IIP, on RN lower side of steering column. 201- 9-A
................. .................... 6312 (2 cavities) Behind rear license plate 201-17-A
............. ..... 6103 (Except VIN E) On radiator support, behind LN headlights 201-16-A
.......................... .... 6104
On radiator support, behind RH headlights. 201-16-A
.......................... ............ 6200 Behind IIP, left of steering column 201-10-A
........................ .......................... 6303 Center of end panel. 201-17-B
.......................... .... S105. Front lights harness, behind LH headlights. 201-16-A
.......................... S106. Front lights harness, LN front corner of engine
compartment..
.......................... 201-1543
.......................... .... S107. Front lights harness, behind LH headlights. 201-16-A
.......................... ..... S109. Front lights harness, left of RH headlights 201-16-A
S110. .......................... Front lights harness, behind RH headlights .... 201-16-A
S205. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
S225. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
S226. .......................... IIP harness, at head of console. ............... 201-10-A
S227. .......................... IIP harness, behind instrument cluster. ........ 201-10-A
S302. .......................... Rear lights harness, LW side of end panel. ...... 201-17-B
.......................... S307. Rear lights harness, LH rear corner of cargo
compartment..
.......................... 201-17-B
.......................... ..... S308. Rear lights harness, behind LH rear lights. 201-17-A
S311. .......................... Rear lights harness, left of RH backup lights ... 201-17-A
3. If the Hazard Lights do not turn off, replace the
4. If the Hazard Lights stay on (do not flash),
Turn-Hazard Switch.
replace the Hazard Flasher.
(Continued on next page)

EXTERIOR LlGHTS
(Continued from previous page)
Park/MarkerflaIl/License UgMs
1. If the Park, Marker and Tail Lights do not
work, cheek the Tail Fuse, Light Switch, and
BRN (9) wires for continuity (see schematic).
2. If the Front Marker and the Park Lights dd not
work, check the connection at 6100 and re-
lated wiring (see schematic).
3. If the Park Lights do not turn off, replace the
Light Switch.
s Go to System Diagnosis for diagnostic tests.
@ Do the tests listed for your symptom in the
Symptom
Able bezaw.
@ Tests follow the Symptom Table.
SYMPTOM arABhE
A: TURN LIGHTS TEST
SYMPTOM
Turn Lights do not
work, but Hazard
Lights work
Hazard Lights do not
work, but Stop Lights
work
Stop Lights do not
work, but Turn
Signals work
Stop-Turn Lights on
one or both sides do
not work
B: HAZARD LIGHTS TEST (TABLE 2)
DO TEST
A: Turn Lights Test
B: Hazard Lights
Test
6: Stop Lights Test
6: Stop Lights Test
Connect: TEST LAMP
At: CONNECTOR C210
(Connected)
Condition:
Ignition Switch: RUN
o If the result is correct, replace the Hazard
Flasher.
1. Go to Table 2.
B: HAZARD LIGHTS TEST (TABLE 1)
Connect: FUSED JUMPER
At: CONVENIENCE
CENTER
Conditions:
r Hazard Flasher: REMOVED
Hazard Switch:
HAZARD
Measure: VOLTAGE
At: CONNECTOR 621 0 (Disconneded)
Condition:
Hazard Flasher: CONNECTED
For
Diagnosis
See 1
Connect
Between
L (PPL) &
Ground
I Measure ( Correct ( For
e If test lamp lights, replace the
ard Switch.
1. Check Turn Flasher and PPE (16) wire for
an open.
Correct
Result
Test Lamp
lights
For
Diagnosis
See 1
Jumper
Between
A (QRN) & B
(BRN)
Between I Voltage I Diagnosis
Correct Result
All Turn
Lights turn on
( If the voltage is correct, replace the Turn- I
(BRN) &
Ground
Hazard Switch.
1. Check ORN (140) and BRN (27) wires for an
open.
6: STOP LIGHTS TEST
At: 6208 (Fernale Half) (Disconnected)
Condition:
Brake Pedal: DEPRESSED and HELD
Battery See 1
Connect
Behvveen
I CEKyy 1 Test Lamp
lights I See 2 I
B (LT BLU) &
Ground
I Ground I I I
Correct
Result
(Continued on facing page)
For
Diagnosis
Test Lamp
lights See 1

(Continued from facing page)
@ If the results are correct for the Trans AM,
check WHT (17) wire to the Turn-Hazard
Switch. Replace the Turn-Hazard Switch if
the wiring is OK and the Rear Turn Lights
light; for the Firebird, check the bulb,
socket, and related wiring (see schematic).
1. Check the Brake Switch,
LT BLU (20) and
ORN (140) wires for continuity. Repair1
replace as necessary.
2. Check the Brake Switch, ORN (140) and LT
BLU (820) wires for continuity.
Repairlre-
place as necessary.
GlRGUlT OPERATION
Turn Lights
With the Ignition Switch in RUN, BULB TEST,
or START, voltage is applied through the TURN
BIU Fuse and Turn Flasher to the normally closed
pole of the Hazard Switch in the Turn-Hazard
Switch.
With the Turn Switch in TURN LEFT position,
voltage is applied from the Turn Switch through
the LT BLU wires to the LH Turn Indicator and
the LH Front
ParWTurn Light. Voltage is applied
through the YEL wires to the LH Rear Turn
Lights. The lights go on immediately. They begin
to flash when the current flow heats up the tim-
ing element in the flasher and it repeatedly opens
and closes the circuit. When
voltage is applied to the LH Front
Park1
Turn Light, voltage will also be applied to the LH
Front Marker Light. If the Light Switch is OFF,
current will flow to ground through
S105 and the
many lights connected in parallel to ground.
These lights provide low resistance paths to
ground. The Marker Light will flash with the
Turn Lights. The lights used for the ground path
will not flash, however, since the voltage drop
across the Marker Light is much higher than that
across the other lights.
When the Light Switch is in either PARK or
HEAD, voltage is applied through the Tail Fuse,
Light Switch, and
S105 to the Marker and Park
Lights. If the Turn-Hazard Switch is in TURN
LEFT, the LH Front Marker Light has battery
voltage at both terminals and goes out. When the
flasher stops supplying voltage to the Turn Light,
the Marker Light is grounded through the Turn
Light and goes on. In this way, the LN Front
Marker flashes on when the LH Front
ParkITurn
Light goes off, and off when the Turn Light goes The
Front Marker Lights flash in HAZARD,
just as they did in TURN RIGHT and TURN
LEFT. If the Light Switch is in OFF, they flash on
when the Hazard Lights are on. If the Light
Switch is in either PARK or HEAD, they flash on
when the Hazard Lights are off, and off when the
Hazard Lights are on.
In HAZARD, the turn circuit is always open,
and the Hazard Flasher controls the lights.
Stop Lights
Voltage is applied at all times through the
STOP
HA% Fuse to the Brake Switch. When the
brake pedal is depressed, the contacts in the
Brake Switch close.
The Trans Am Stop Lights receive voltage
through the WHT wires that feed the Turn-Haz-
ard Switch. With the switches in the positions
shown in the schematic, the Stop Lights are con-
nected to the WHT wire through the YEL and DK
GRN wires and the turn switches. They will come
on when the Brake Switch is closed. The
Firebird on.
With
RIGHT, Stop
Lights are connected directly to the Brake
the Turn-Hazard Switch in TURN
Switch.
the circuit operation is similar.
For the High Level Stop Light, voltage is ap-
plied directly from the Brake Switch to the Nigh
Hazard Lights Level Stop Light.
Voltage is applied at all times through the
STOP-HAZ Fuse and the Hazard Flasher to the
normally open poles of the Hazard Switch in the
Turn-Hazard Switch. With the Hazard Switch in
HAZARD, current flows through the assembly
using all four paths used by both Front and Rear
Turn Lights. All of the Turn Lights and both Turn
Indicators flash on and off.
(Continued on next page)

EXTERIOR LIGHTS WITH LAMP MONITOR I:
TROUBLESHOOTING HINTS
r Try the follovving checks before doing the
Systern Diagnosis .
1 . If neither the Turn Lights nor the Back Up
Lights work. check the TURN
BIU Fuse .
2 . If neither the Stop Lights nor the Hazard
Lights work. check the STOP-HAZ Fuse
.
3 . If only one light does not operate. check bulb.
socket. and related wiring (see schematic)
.
4 . If one of the Turn Indicators goes on when the
Park Lights are turned on. check the Front
Turn Light on that side
.
5 . For any of the following symptoms. replace the
Turn-Hazard Switch:
Some Turn Lights work and all Hazard
Lights work
.
@ Some Hazard Lights work and all Turn
Lights work
.
Hazard Lights do not turn off .
6 . If the Turn Lights stay on (do not flash) in both
TURN LEFT and TURN RIGHT. replace the
Turn Flasher
.
7 . If the Hazard Lights stay on (do not flash) in
HAZARD. but the Stop Lights go off normally.
replace the Hazard Flasher
.
8 . If no Park. Tail. or License Lights work.
check the Light Switch. and the
ORNIBLK
(240) and BRN (9) wires for an open (see
schematic)
.
COMPONENT LOCATION Page-Figure
..... Brake Switch .................... Above brake pedal. on brake pedal support 201- 9-A
......... 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
Lights Monitoring Module
......... Behind IIP. at base of steering column
......... Turn Flasher .................... Behind IIP. to right of steering column 201-
9-A
TurnIHazard Switch .............. Top of steering column
.. ClOO (42 cavities) ................ LW front of dash. left of brake master cylinder 201- 0-A
................. C105 (2 cavities) Behind
LH side of IIP. near fuse block
.................. 6205 (3 cavities) ................. Behind LH side of rear seat 201-17-6
.................. ................. C208 (8 cavities) Behind LR side of rear seat 201-17-C
. C210 (11 cavities) ................ Behind IIP. on RH lower side of steering column 201-
9-A
.................... C312 (2 cavities) ................. Behind rear license plate 201-17-A
..... ............. 6103
(Except VIN E) On
radiator support. behind LH headlights 201-16-A
..... .......................... 6104 On
radiator support. behind RH headlights 201-16-A
............ .......................... 6200 Behind IIP. left of steering column 201-10-A
......................... .......................... 6303 Center of end panel 201-17-B
..... ........................... S105 Front lights harness. behind LH headlights 201-16-A
S106
........................... Front lights harness. LH front corner of engine
............................ compartment 201-15-B
..... ........................... S107 Front lights harness. behind LH headlights 201-16-A
..... S109 ........................... Front lights harness. left of RH headlights 201-16-A
.... S110 ........................... Front lights
harness. behind RH headlights 201-16-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
....... S302 ........................... Rear lights harness. LH side of end panel 201-17-B
S307
........................... Rear lights harness. LH rear corner of cargo
............................ compartment 201-17-B
...... S308 ........................... Rear lights harness. behind LH rear lights 201-17-A
S311
........................... Rear lights harness. left of RW back up lights ... 201-17-A

EXTERIOR LIGHTS WITH LAMP MONITOR 1 g
(Continued from previous page)
9. If the Stop Lights stay on without the brake
pedal pressed,
adjustlreplace the Brake
Switch.
10. If the Park Lights do not
turn off, replace
the Light Switch.
11.
If only the High Level Stop Light does not
work, check the Brake Switch,
High Level
Stop Eight, the LT
BEUIBLK and YEL
(820) wires, and the BLK (150) wires for an
open.
12. If a
Turn Indicator lights steadily (does not
flash) when the Turn
Signal is on, check the
Turn Lights on that side.
Go to System Diagnosis for diagnostic tests.
SYSTEM DIAGNOSIS
@ Diagnostic steps for the symptoms listed in
the following table are listed after the table.
SYMPTOM TABLE
k The Turn Lights do not work, but the
Hazard Lights work
B: The Hazard Lights do not work, but the
Stop Lights and
Turn Lights work
@: The Stop Lights do not work, but the Turn
Signals work
Lights on one or both sides
do not work
E: The Front Turn Light and Wn Indicator
on one or both sides do not light
A: THE TURN LIGHTS DO NOT MRK,
BUT THE HAZARD LIGHTS WORK
Connect: TEST UMP
At: CONNECTOR 6218 (Connected)
Condition:
@ lanition Switch: RUM 1
Correct For Diagnosis
Connect
Result of Incorrect Setween Results
L (PPL) & Test Lamp
See 1 Ground lights
Jf *.he test lamp lights, replace the Turn-
Hazard Switch.
1. Check the Turn Flasher, BIU Fuse,
and the DK
BLU (75) and PPL (16) wires
for
an open (see schematic).
B: THE HAZARD LIGHTS DO NOT WORK,
BUT THE STOP LIGHTS AND BURN
LIGHTS WORK (TABLE 1)
At: CONVENIENCE CENTER (Disconnected)
Conditions:
e Hazard Flasher: REMOVED
* Hazard Switch: HAZARD
Jumper Correct For Diagnosis
Result of
Incorrect
Betvveen Results
B (BRN) & A All
the Turn
I (ORN) I Lights light I See 1 I
If the result is correct, replace the Hazard
Flasher.
1. Go to Table 2.
B: THE HAZARD LIGHTS DO NOT WORK,
BUT THE STOP LIGHTS AND TURN
LlGMTS WORK (TABLE 2)
Connect: TEST WMP
At: CONNECTOR 6210 (Connected1
For Diagnosis
Connect
of incorrect 1 Bemeen I Resun 1
K (BRN) & Test Lamp
Ground lights
If the result is correct, replace the Turn-
Hazard Switch. 1
1. Check the ORN (140) and BRN (27) wires
for an open (see schematic).
C: THE STOP LIGHTS DO NOT WORK
BUT THE TURN SIGNALS WQR:'" -. .-
Connect: TEST EAMP
At: CONNECTOR C208 (Connected1
Condition:
r Brake Pedal: DEPRESSED
Connect Correct
For Diagnosis
Result of
Incorrect
Between Results
B (LT BLU) & Test Lamp
lights See 1 Ground
If the test lamp lights, with Trans Am,
check
WHT (17) wire for an open, then re-
place
TurnJHazard Switch if WHT wire is
good. With Firebird, check
LT BLU (20)
wire for an open (See schematic).
1.
ChecWadjust the Brake Switch, and check
the
WWT (17) and ORN (140) wires for an
open (see schematic).
(Continued on facing page)