G SENSOR
The G sensor senses deceleration during braking to determine whether the vehicle is being driven on a high
road (asphalt road, etc.) or a low road (snow-covered road, etc.). It then sends a signal to the ABS con-
trol unit.
The reed switch turns on when it is affected by a magnetic ®eld. During sudden deceleration (braking on a
high road), the weight moves and the magnet in the weight moves away from the reed switch. The mag-
netic ®eld then diminishes and the reed switch turns off.
ABS ACTUATOR AND ELECTRIC UNIT
The ABS actuator and electric unit contains:
+An electric motor and pump
+ Two relays
+ Six solenoid valves, each inlet and outlet for
Ð LH front
Ð RH front
Ð Rear
+ ABS control unit
This component controls the hydraulic circuit and increases, holds
or decreases hydraulic pressure to all or individual wheels. The
ABS actuator and electric unit are not disassemble.
ABS actuator operation
Inlet solenoid
valve Outlet solenoid
valve
Normal brake operation OFF (Open) OFF (Closed) Master cylinder brake ¯uid pressure is directly trans-
mitted to wheel cylinder via the inlet solenoid valve.
ABS operation Pressure hold ON (Closed) OFF (Closed)
Hydraulic circuit is shut off to hold the wheel cylinder
brake ¯uid pressure.
Pressure
decrease ON (Closed) ON (Open) Wheel cylinder brake ¯uid is sent to reservoir via the
outlet solenoid valve. Then it is pushed up to the
master cylinder by pump.
Pressure
increase OFF (Open) OFF (Closed) Master cylinder brake ¯uid pressure is transmitted to
wheel cylinder.
SBR189E
SBR176E
ANTI-LOCK BRAKE SYSTEM
System Description (Cont'd)
BR-35
SELF-DIAGNOSTIC RESULTS MODE
Diagnostic item Diagnostic item is detected when ...Diagnostic
procedure
FR RH SENSOR .1
[OPEN] +
Circuit for front right wheel sensor is open.
(An abnormally high input voltage is entered.) 1
FR LH SENSOR .1
[OPEN] +
Circuit for front left wheel sensor is open.
(An abnormally high input voltage is entered.) 1
RR RH SENSOR .1
[OPEN] +
Circuit for rear right sensor is open.
(An abnormally high input voltage is entered.) 1
RR LH SENSOR .1
[OPEN] +
Circuit for rear left sensor is open.
(An abnormally high input voltage is entered.) 1
FR RH SENSOR .1
[SHORT] +
Circuit for front right wheel sensor is shorted.
(An abnormally low input voltage is entered.) 1
FR LH SENSOR .1
[SHORT] +
Circuit for front left wheel sensor is shorted.
(An abnormally low input voltage is entered.) 1
RR RH SENSOR .1
[SHORT] +
Circuit for rear right sensor is shorted.
(An abnormally low input voltage is entered.) 1
RR LH SENSOR .1
[SHORT] +
Circuit for rear left sensor is shorted.
(An abnormally low input voltage is entered.) 1
ABS SENSOR .1
[ABNORMAL SIGNAL] +
Teeth damage on sensor rotor or improper installation of wheel sensor.
(Abnormal wheel sensor signal is entered.) 1
FR RH IN ABS SOL
[OPEN] +
Circuit for front right inlet solenoid valve is open.
(An abnormally low output voltage is entered.) 2
FR LH IN ABS SOL
[OPEN] +
Circuit for front left inlet solenoid valve is open.
(An abnormally low output voltage is entered.) 2
RR IN ABS SOL
[OPEN] +
Circuit for rear inlet solenoid valve is open.
(An abnormally low output voltage is entered.) 2
FR RH IN ABS SOL
[SHORT] +
Circuit for front right inlet solenoid valve is shorted.
(An abnormally high output voltage is entered.) 2
FR LH IN ABS SOL
[SHORT] +
Circuit for front left inlet solenoid valve is shorted.
(An abnormally high output voltage is entered.) 2
RR IN ABS SOL
[SHORT] +
Circuit for rear inlet solenoid valve is shorted.
(An abnormally high output voltage is entered.) 2
FR RH OUT ABS SOL
[OPEN] +
Circuit for front right outlet solenoid valve is open.
(An abnormally low output voltage is entered.) 2
FR LH OUT ABS SOL
[OPEN] +
Circuit for front left outlet solenoid valve is open.
(An abnormally low output voltage is entered.) 2
RR OUT ABS SOL
[OPEN] +
Circuit for rear outlet solenoid valve is open.
(An abnormally low output voltage is entered.) 2
FR RH OUT ABS SOL
[SHORT] +
Circuit for front right outlet solenoid valve is shorted.
(An abnormally high output voltage is entered.) 2
FR LH OUT ABS SOL
[SHORT] +
Circuit for front left outlet solenoid valve is shorted.
(An abnormally high output voltage is entered.) 2
RR OUT ABS SOL
[SHORT] +
Circuit for rear outlet solenoid valve is shorted.
(An abnormally high output voltage is entered.) 2
ABS ACTUATOR RELAY
[ABNORMAL] +
Actuator solenoid valve relay is ON, even if control unit sends off signal.
+ Actuator solenoid valve relay is OFF, even if control unit sends on signal. 2
ABS MOTOR RELAY
[ABNORMAL] +
Circuit for ABS motor relay is open or shorted.
+ Circuit for actuator motor is open or shorted.
+ Actuator motor relay is stuck. 3
BATTERY VOLT
[VB-LOW] +
Power source voltage supplied to ABS control unit is abnormally low. 4
CONTROL UNIT +Function of calculation in ABS control unit has failed. 6
G-SENSOR
[ABNORMAL] +
G sensor circuit is open or shorted. 5
. 1: If one or more wheels spin on a rough or slippery road for 40 seconds or more, the ABS warning lamp will illuminate. This does
not indicate a malfunction. Only in the case of the short-circuit (Code Nos. 26, 22, 32 and 36), after repair the ABS warning
lamp also illuminates when the ignition switch is turned ``ON''. In this case, drive the vehicle at speeds greater than 30 km/h (19
MPH) for approximately 1 minute as speci®ed in ``SELF-DIAGNOSIS PROCEDURE'', BR-47. Check to ensure that the ABS
warning lamp goes out while the vehicle is being driven.
TROUBLE DIAGNOSES
CONSULT Inspection Procedure (Cont'd)
BR-52
DATA MONITOR MODE
MONITOR ITEM CONDITION SPECIFICATION
FR RH SENSOR
FR LH SENSOR
RR SENSOR
RR RH SENSOR
RR LH SENSORDrive vehicle.
(Each wheel is rotating.)
Wheel speed signal
(Almost the same speed as speedometer.)
STOP LAMP SW Brake is depressed. Depress the pedal: ON
Release the pedal: OFF
G-SWITCH Vehicle is driven.
Vehicle is stopped.
Brake is applied.During sudden braking while driving on high roads (asphalt
roads, etc.): OFF
While vehicle is stopped or during constant-speed driving: ON
FR RH IN SOL
FR RH OUT SOL
FR LH IN SOL
FR LH OUT SOL
RR IN SOL
RR OUT SOL 1. Drive vehicle at speeds over
30 km/h (19 MPH) for at
least one minute.
2. Engine is running. Operating conditions for each solenoid valve are indicated.
ABS is not operating: OFF
MOTOR RELAY ABS is not operating: OFF
ABS is operating: ON
ACTUATOR RELAY Ignition switch is ON or
engine is running.Ignition switch ON (Engine stops): OFF
Engine running: ON
WARNING LAMP ABS warning lamp is turned on: ON
ABS warning lamp is turned off: OFF
BATTERY VOLT Power supply voltage for control unit
ACTIVE TEST MODE
TEST ITEM CONDITION JUDGEMENT
FR RH SOLENOID
FR LH SOLENOID
REAR SOLENOID Engine is running.Brake ¯uid pressure control operation
IN SOL OUT SOL
UP (Increase):
KEEP (Hold):
DOWN (Decrease): OFF
ON
ONOFF
OFF
ON
ABS MOTOR ABS actuator motor
ON: Motor runs (ABS motor relay ON)
OFF: Motor stops (ABS motor relay OFF)
G SWITCH Ignition switch is ON. G SWITCH (G SENSOR),
ON: Set G SWITCH MONITOR ``ON''
(G switch circuit is closed.)
OFF: Set G SWITCH MONITOR ``OFF'' (G switch circuit is open.)
Note: Active test will automatically stop ten seconds after the test starts. (LIMIT SIGNAL monitor shows ON.)
TROUBLE DIAGNOSES
CONSULT Inspection Procedure (Cont'd)
BR-55
ENGINE COOLANT TEMPERATURE COMPENSATION (During driving)
Input/output signal line
Crankshaft position sensor (TDC)cEngine speed
ECM
c
Injection
timing con-
trol valveEngine coolant temperature sensorcEngine coolant temperature
Needle lift sensor
cInjection timing
For better exhaust efficiency under cool engine conditions, the fuel
injection timing is controlled within a compensation range depend-
ing on the engine speed, engine coolant temperature and amount
of fuel injected.
Air Conditioning Cut Control
INPUT/OUTPUT SIGNAL LINE
Air conditioner switchcAir conditioner ``ON'' signal
ECM
cAir
conditioner
relayAccelerator position sensorcAccelerator valve opening angle
Vehicle speed sensor
cVehicle speed
Engine coolant temperature sensor
cEngine coolant temperature
SYSTEM DESCRIPTION
This system improves acceleration when the air conditioner is used.
When the accelerator pedal is fully depressed, the air conditioner is turned off for a few seconds.
When engine coolant temperature becomes excessively high, the air conditioner is turned off. This continues
until the coolant temperature returns to normal.
SEF652S
ENGINE AND EMISSION BASIC CONTROL SYSTEM DESCRIPTION
Fuel Injection Timing System (Cont'd)
EC-19
SYSTEM
Ð ECCS systemMalfunction
SYMPTOM
Reference page Feature of symptom
Check point
HARD/NO START/
RESTART (EXCP. HA) ENGINE STALL HESITATION/SURGING/FLAT SPOT KNOCK/DETONATION
LACK OF POWER
POOR ACCELERATION
HI IDLE
LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEAT/HIGH ENGINE COOLANT TEMPERATURE
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION ABNORMAL SMOKE COLOR
DEAD BATTERY (UNDER CHARGE) Malfunction indicator lamp illuminates.
Can be detected by CONSULT?
Fuel cut
NO START (with ®rst ®ring) NO START (without ®rst ®ring)
HARD TO START WHEN ENGINE IS COLD
HARD TO START WHEN ENGINE IS HOT
AT IDLE
DURING DRIVING
WHEN DECELERATINGBLACK SMOKE WHITE SMOKE
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM AP HAECCS
Start signal circuit open, shortjjEC-163 Start control does not function.
Neutral position switch circuitopen, shortjjj
EC-170
ground shortjj
Accelerator position switch (Idle) cir-
cuitopen, ground shortjj j
EC-165
shortjjj jjAccelerator position sensor NG
signal is output.
Accelerator position switch (Full) cir-
cuitopen, shortjjj jjEC-165
Ignition switch circuitopenj jjj
EC-63
shortEngine does not stop.
Power supply for ECM circuitopenjjj
EC-63
shortjj
Throttle control solenoid valve circuitopen, short
EC-156Does not operate.
ground shortjj jDoes not stop operating.
EGRC-solenoid valve A, B circuitopen, short
EC-156
ground shortjDoes not stop operating.
Glow relay circuitopenjjjjj
EC-151Glow lamp does not turn on.
shortGlow lamp does not turn off.
ECCS relay (Self-shutoff) circuitopenjjjj
EC-63
shortjjGround short makes engine
unable to stop.
ECM, Connector circuit open, shortjjjjjjjjjjjjj jjjjjjjjjjjjEC-111
Air conditioner relay circuitopen
EC-187Air conditioner does not operate.
shortAir conditioner does not stop
operating.
Air conditioner switch circuitopen, ground short
EC-187Air conditioner does not stop
operating.
shortAir conditioner does not work.
TROUBLE DIAGNOSIS Ð General Description
Symptom Matrix Chart (Cont'd)
EC-50
CONSULT Reference Value in Data Monitor
Mode
Remarks:
+Speci®cation data are reference values.
+Speci®cation data are output/input values which are detected or supplied by the ECM at the connector.
* Speci®cation data may not be directly related to their components signals/values/operations.
MONITOR ITEM CONDITION SPECIFICATION
CKPSzRPM (TDC)
+Tachometer: Connect
+Run engine and compare tachometer indication with the CONSULT value.Almost the same speed as the CON-
SULT value. CKPSzRPM (REF)
CMPSzRPM-PUMP
COOLAN TEMP/S+Engine: After warming up More than 70ÉC (158ÉF)
VHCL SPEED SE+Turn drive wheels and compare speedometer indication with the CONSULT
valueAlmost the same speed as
the CONSULT value
FUEL TEMP SEN+Engine: After warming up More than 40ÉC (104 ÉF)
ACCEL POS SEN+Ignition switch: ON
(Engine stopped)Accelerator pedal: released 0.40 - 0.60V
Accelerator pedal: depressed Approx. 4.0V
FULL ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: depressed ON
Except above OFF
ACCEL SW (FC)+Ignition switch: ON
(Engine stopped)Accelerator pedal: released CLOSE
Accelerator pedal: slightly open OPEN
OFF ACCEL SW+Ignition switch: ON
(Engine stopped)Accelerator pedal: released ON
Accelerator pedal: slightly open OFF
C/SLEEV POS/S+Engine: After warming up 1.0 - 3.5V
BATTERY VOLT+Ignition switch: ON (Engine stopped) 11 - 14V
P/N POSI SW+Ignition switch: ONShift lever: Neutral/Park ON
Except above OFF
START SIGNAL+Ignition switch: ON®START®ON OFF®ON®OFF
AIR COND SIG+Engine: After warming up, idle the
engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
IGN SW+Ignition switch: ON®OFF ON®OFF
WARM UP SW+Ignition switch: ONHeat up switch: ON ON
Heat up switch: OFF OFF
MAS AIR/FL SE+Engine: After warming up
+Air conditioner switch: OFF
+Shift lever: ``N''
+No-loadIdle 1.6 - 2.0V
ACT INJ TIMG+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle þ9.5 to þ12.0É
2,000 rpm þ10.0 to þ15.5É
INJ TIMG C/V+Engine: After warming up, idle the engine. Approx. 50%
DECELER F/CUT+Engine: After warming upIdle OFF
When accelerator pedal is released
quickly with engine speed at 3,000 rpm
or more.ON
FUEL CUT S/V+Ignition switch: ON®OFF ON®OFF
GLOW RLY+Refer to EC-151.
TROUBLE DIAGNOSIS Ð General Description
EC-51
ECM HARNESS CONNECTOR TERMINAL LAYOUT
ECM INSPECTION TABLE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
1WThrottle control solenoid
valveEngine is running.
(Warm-up condition)
Idle speedApproximately 0.4V
Engine is running.
(Warm-up condition)
Revving engine from idle to 2,500 rpmBATTERY VOLTAGE
(11 - 14V)
4 B/Y ECCS relay (Self-shutoff)Ignition switch ``ON''
Ignition switch ``OFF''
For a few seconds after turning ignition switch
``OFF''0 - 1.5V
Ignition switch ``OFF''
A few seconds passed after turning ignition
switch ``OFF''BATTERY VOLTAGE
(11 - 14V)
5 Y/B TachometerEngine is running.
(Warm-up condition)
Idle speedApproximately 1.0 - 2.0V
SEF715V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 1.0 - 2.0V
SEF716V
SEF064P
TROUBLE DIAGNOSIS Ð General Description
ECM Terminals and Reference Value (Cont'd)
EC-55
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
40
44LCrankshaft position sensor
(TDC)Engine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF720V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0V
SEF721V
41
45WCamshaft position sensor
(PUMP)Engine is running.
(Warm-up condition)
Idle speedApproximately 0V
SEF722V
Engine is running.(Warm-up condition)
Engine speed is 2,000 rpm.Approximately 0V
SEF723V
42 L/G
Data link connector for
CONSULTEngine is running.
Idle speed (CONSULT is connected and
turned on)Approximately 0V
64 Y/GApproximately0-12V
65 Y/RApproximately0-9V
46 Y Adjustment resistor Ignition switch ``ON''
Approximately 0 - 4.6V
(Voltage varies with part
number of adjustment
resistor.)
47
52B/WCrankshaft position sensor
(TDC) groundEngine is running.
(Warm-up condition)
Idle speedApproximately 0V
48 G/RAccelerator position sen-
sor power supplyIgnition switch ``ON''
Approximately 5V
49 G/RSensor's power signal to
TCMIgnition switch ``ON''
Approximately 5V
TROUBLE DIAGNOSIS Ð General Description
ECM Terminals and Reference Value (Cont'd)
EC-59