1987 MAZDA 626 turn signal

ISC SYSTEM 4C
COMPONENT DESCRIPTION
Component Function Remark
A/C switch Detects air conditioner operation; sends
signal to engine control unit Switch ON when air conditioner
operating
Air valve When cold, supplies bypass air into dy-namic chamber • Engine speed increased to shorten warm-up period • Thermo wax type
• Installed in BAC valve
Clutch switch Detects in-gear condition; sends signal to engine control unit Switch ON when clutch pedal released
E/L control unit Detects that E/L is being applied; sends
signal to engine control unit
Engine control unit Detects signals from input sensors and switches; controls solenoid valve (Idle speed control)
Idle switch Detects when throttle valve fully closed;
sends signal to engine control unit
Installed on throttle body
Ne signal pick-up Detects crank angle at 180° intervals; sends signal to engine control unit Installed in distributor
Neutral switch Detects in-gear condition; sends signal to engine control unit
Switch ON when in gear
P/S pressure switch Detects P/S operation; sends signal to engine control unit Switch ON when steering wheel turned right or left
Solenoid valve (Idle speed control) Controls bypass air amount • Controlled by duty signal from engine control unit • Installed in BAC valve
• Operates idle-up
Test connector For initial idle speed adjustment • Gerrn, 1-pin
• Idle speed feedback control cancelled when connector grounded
Water thermo sensor Detects coolant temperature; sends
signal to engine control unit
76G04C-078
4C—45

4C CONTROL SYSTEM
ENGINE CONTROL UNIT
Engine Signal Monitor (49 9200 162) and Adapter (49 9200 163).
Adapter harness 49 9200 163
Engine wiring harness^
Selector switch
' —
Monitor switch
49 9200 162
Control unit terminal number
Terminals (A and B)
Q IIIM«I
76G04C-178
The Engine Signal Monitor (49 9200 162) is used to check the control unit terminal voltages.
How to Use the Engine Signal Monitor
1. Connect the Engine Signal Monitor (49 9200 162) between the engine control unit and the en-
gine harness using the adapter (49 9200 163).
2. Turn the selector switch and monitor switch to select the terminal number.
3. Check the terminal voltage.
Caution
Never apply voltage to terminals A and B.
4C—98

CONTROL SYSTEM 4C
76G04C-203
76G04C-204
76G04C-205
G Signal Inspection
1. Remove the distributor. (Refer to section 5.)
2. Reconnect the distributor to the wiring harness.
3. Remove the rubber boot from the distributor con-
nector.
4. Connect a volt meter between the A terminal and
a ground.
5. Turn the shaft and check that the distributor gener-
ates one pulse signal I per one turn.
Ne signal Inspection
1. Remove the distributor. (Refer to Section 5.)
2. Reconnect the distributor to the wiring harness.
3. Remove the rubber boot from the distributor con-
nector.
4. Connect a voltmeter between the B terminal and
a ground.
5. Turn the shaft and check that the distributor gener-
ates four pulse signals per one turn.
Oxygen Sensor Heater
1. Disconnect the oxygen sensor connector.
2. Check resistance between terminals B and C.
Specification: approx. 6 Q
Knock Sensor (Leaded fuel)
1. Warm up the engine and rum it at idle.
2. Ground the test connector (Green, 1-pin) with a
jumper wire.
3. Tap the engine hanger with a hammer and verify
that the ignition timing retards.
4. If not correct, check the knock sensor.
76G04C-206
4C-109

7B TROUBLESHOOTING (G4A-EL)
STEP 3 (SIGNAL INSPECTION)
In this step, the input and output signals are checked
with the EC-AT Tester.
The Tester checks for proper operation of the vari-
ous switches and sensors in the EC-AT system. It also
checks the control unit for output of the various con-
trol signals. Powertrain slippage is also checked.
Inspection Procedure
1. Disconnect the connectors from the EC-AT con-
trol unit.
2. Connect the adaptor harness between the control
unit and the connectors.
3. Turn the ignition switch and main switch ON.
4. Check indication of the respective light or digital
display in each condition, referring to the indica-
tion table below.
Indication table of light and digital display
Item Indication Condition Possible cause
Input (Light)
L ON L range L OFF Other ranges
S
ON S range
INHIBITOR
S OFF Other ranges Inhibitor switch or wiring SW
D ON D range
Inhibitor switch or wiring
D
OFF Other ranges
P,N
ON P or N range P,N OFF Other ranges
HOLD SW ON Hold switch pushed Hold switch or wiring HOLD SW
OFF Hold switch released
Hold switch or wiring
MODE SW ON Power mode Mode switch or wiring MODE SW
OFF Economy mode
Mode switch or wiring
IDLE SW ON Throttle valve fully closed Idle switch or wiring IDLE SW
OFF Throttle valve open
Idle switch or wiring
7B-24

1 4 HEADLIGHT AND COMBINATION LIGHT
HEADLIGHT AND COMBINATION LIGHT
REMOVAL AND INSTALLATION
1. Disconnect the negative battery cable.
2. Remove in the sequence shown in the figure, referring to removal note for the specially marked parts.
3. Install in the reverse order of removal.
76G14X-005
1. Screw
2. Turn signal light assembly
3. Screw
4. Radiator grille
5. Bolts
6. Bolts
7. Headlight assembly
8. Screws
9. Light garnish
10. Headlight bulb
60 + 55W/55W
11. Parking light bulb 5W
12. Turn signal light bulb
21W
14—28

HEADLIGHT AND COMBINATION LIGHT 1 4
76G14X-006
1. Screw 6. Bolts
2. Turn signal light assembly 7. Fastener
3. Screw 8. Screw
4. Radiator grille 9. Light garnish
5. Bolts 10. Headlight assembly
11. Headlight bulb
60 + 55/55W
12. Parking light bulb 5W
13. Turn signal light bulb
21W
14—29

1 4 HEADLIGHT AND COMBINATION LIGHT
76G14X-007
86U14X-070
Removal Note
Turn signal light (Coupe/MX-6)
1. Remove the screws shown in the figure.
2. Disconnect the turn signal light connector.
3. Remove the turn signal light assembly.
Turn signal light (Sedan and Hatchback)
1. Remove the screws shown in the figure.
2. Disconnect the turn signal and parking light con-
nector.
3. Remove the turn signal and parking light assemble.
76G14X-008
14-30

1 4 REAR COMBINATION LIGHTS
REAR COMBINATION LIGHTS
REMOVAL AND INSTALLATION
1. Disconnect the negative battery cable.
2. Remove in the sequence shown in the figure.
3. Install in the reverse order of removal.
76G14X-010
Hatchback
1. End trim
2. Nuts
3. Lens and body
4. Cover
5. Bulb: Turn signal light 21W
Brake and tail light 21W
Side marker light 5W
Sedan and Coupe/MX-6
1. End trim
2. Nuts
3. Lens and body
4. Cover
5. Bulb: Turn signal light 21W
Brake and tail light 21W
Side marker light 5W
14—32