1988 PONTIAC FIERO Service Repair Manual

a HEADLIGHT DOORS l e
----- FUSIBLE
HEADLIGHTS: FOG LIGHTS

HEADLIGHT DOORS
SYSTEM CHECK COMPONENT LOCATION Page-Figure
Use the System Check Table as a guide to Fuse Block. ..................... Behind LN side of IIP, below light switch. ...... 201-10-A
normal operation. Fusible Link D .................. Front lights harness, near LR side of dash. ..... 201-16-A
..... .................. Refer to System Diagnosis for a list of symp- Fusible Link E. Front lights harness, near LN side of dash. 201-16-A
..... .................. toms and
diagnostic steps. Fusible Link G Front lights harness, near LH side of dash. 201-16-A
.......................... Headlight
Door Module ........... LH front of dash. 201-16-A
SYSTEM CHECK TABLE
Refer to System Diagnosis when a result is
not normal.
SYSTEM DIAGNOSIS
a Do the tests listed for your symptom in the
Symptom Table below.
Tests follow the Symptom Table.
SYMPTOM TABLE
B: Left Headlight Door does not operate
C: Right Headlight Door does not operate
-
LH Headlight Door Motor. ........ To right of LH headlight .................... 201-16-A
Lights Monitoring Module.
........ Behind UP, at base of steering column
RH Headlight Door Motor. ........ To left of RN headlight ..................... 201-16-A
C100 (42 cavities) ................ LH front of dash, left of brake master cylinder .. 201- 0-A
6103 (Except VIN
E) ............. On radiator support, behind LN headlights ..... 201-16-A
A: NEITHER HEADLIGHT DOOR
OPERATES PROPERLY
Connect
Between
(Continued in next column) (Continued
from previous column)
I
r If all results are correct, replace Head-
light Door Module.
1. Check RED (2) wire and Fusible Link D
or E for an owen (see schematic).
2. Check TAIL Fuse, Light Switch, and
WHT (103) wire for an open (see
schematic).
3. Check BLK (150) wire for an open.

HEADLIGHT DOORS
B: LEFT HEADLIGHT DOOR DOES NOT
OPERATE PROPERLY
1. Check for mechanical binding.
2. Remove connector C2 from the Headlight
Door Module. (Leave
C1 connected.) Con-
nect fused jumpers from terminal D
(GRYI
BLK) of the connector to terminal A of the
Module, and from terminal C (DK GRNI
WHT) of the connector to terminal
B of
the Module. Operate the Headlights.
0 If LH Headlight Door works, replace Head-
light Door Module.
0 If no Headlight Door works, check wiring to
the motor. Replace the motor as necessary.
6: RIGHT HEADLIGHT DOOR DOES
NOT OPERATE PROPERLY
1. Check for mechanical binding.
2. Remove connector C2 from the Headlight
Door Module. (Leave
C1 connected.) Con-
nect fused jumpers from terminal B (DK
GRN) of the connector to terminal
C of the
Module, and from terminal
A (GRY) of the
connector to terminal D of the module. Oper-
ate the Headlights.
If RH Headlight Door works, replace Head-
light Door Module.
0 If no Headlight Door works, check wiring to
the motor. Replace the motor as necessary.
GlRGUlT OPERATION
Voltage to open the Headlight Doors and to
power the solid state circuitry is applied to the
Headlight Door Module at all times at termi-
nals
B and E of connector 61. With the Light
Switch in OFF, voltage to close the Headlight
Doors is applied to terminal C of connector
C1.
With the Light Switch in HEAD, voltage is
applied to terminal A of connector
C1 to allow
the Headlight Doors to open.
When the Light Switch is moved to HEAD,
voltage is applied to the Headlight Door
Motors. Ground is provided for the motors
through the solid state circuitry until the
Headlight doors are open.
When the Light Switch is moved to OFF,
voltage is reversed across the Headlight Door
Motors. The motors run in the opposite direc-
tion to close the Headlight Doors. When the
doors are closed, the solid state circuitry
senses the motors are not operating and
ground is removed.

> HEADLIGHTS WITH LAMP MONITOR :
I
DONOTMEASURE
FROM FOG LIGHT
RELAY PAGE
103-4
DISTRIBUTION
-- - a 6104 - -

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 WITH LAMP MONITOR
A: LIGHT SWITCH TEST (TABLE 2) (Continued from previous column)
With the Headlight D er
Switch in HI,
Connect: FUSED JUMPER
At: LIGHT
SWITCH CONNECTOR
(Disconnected)
Conditions:
@ Put a 15 amp fuse in the fused jumper
@ Dimmer Switch: LO
( C (RED) & D ( Headlights 1 See (YEL) light I
Jumper
Betvveen
I Put Dimmer Switch in HI I
Correct Result
I 0 If results are correct, replace Light Switch. I
For Diagnosis
Of incorrect
Results
C (RED) & D
(YEL)
1. Check for short to ground in wiring to
I Headlights.
B: DIMMER SWITCH TEST
High Beams
light
Connect: TEST LAMP
At: HEADLIGHT DIMMER SWITCH
COIUNEC-
TOR (Connected)
Conditions: Light Switch: HEAD
@ Dirnmer Switch: LO
See 1
(Continued in next column)
For Diagnosis
Correct
~esu~t Of incorred
1 1 1 Resd% 1
C(YEL)& TestLamp
Ground lights See 1
Ground I
Put
Dimmer Switch in HI
B (LT GRN)
& Test Lamp
lights See 2 Ground
If all results are correct, check wiring to
lights for an open.
1. Check YEL (10) wire for an open.
2. Replace Headlight Dimmer Switch.
CIRCUIT OPERATION
Voltage is applied to the Light Switch
through the Headlights Circuit Breaker. When
the switch is closed in HEAD, voltage is
applied through the YEL wire to the Headlight
Dimmer Switch. With the
D
LO, voltage is applied through the TAN and
BLK matched resistance wires to the Lights
Monitoring Module and to the LH and RH Low
Beam Headlights. The Lo Beam Headlights
turn on.
If either of the Lo Beam Headlights is burned
out, the Lo Beam Comparator detects the open
low beam filament, and the Driver Information
Center (DIC) displays the fault. voltage
is applied through the
LT GRN wire
and the matched resistance wires to the Lights
Monitoring Module and to the LH and
RH Hi
Beam Headlights. The Hi Beam Headlights
turn on. Voltage is also applied through the LT
GRN wire to the Hi Beam
In&cator. The In&-
cator lights whenever voltage is applied to the
high beams.
If either of the Hi Beam Headlights
is burned
out, the Hi Beam Comparator detects the open
high beam filament and the Driver Information
Center (DIC) displays the fault.

HEADLIGHTS WITH LAMP MONITOR: FOGLIGHTS