check engine light SUBARU LEGACY 1997 Service Manual PDF

F: TCS OPERATING INDICATOR LIGHT DOES
NOT GO OFF.
—WHEN STARTING THE ENGINE, ABS
WARNING, TCS WARNING AND TCS OFF
INDICATOR LIGHTS COME ON AND GO OFF
PROPERLY BUT TCS OPERATING
INDICATOR LIGHT ONLY KEEPS ON.—
1. Check harness connector between ABS/TCS
control module and TCS operating indicator
light.
OK
Not OK
Repair harness/connector.
Replace ABS/TCS control module.
B4M0398

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7. Diagnostics Chart for Warning Light Circuit Failure

G: TCS OFF SWITCH DOES NOT FUNCTION.
—TCS OFF INDICATOR LIGHT COMES ON
AND GOES OFF PROPERLY WHEN
STARTING THE ENGINE, WHILE THIS LIGHT
NEITHER COMES ON NOR GOES OFF WHEN
PUSHING THE TCS OFF SWITCH.—
1. Check TCS OFF switch
OK
Not OK
Replace TCS OFF switch.
2. Check harness connector between ABS/TCS
control module and TCS OFF switch.
OK
Not OK
Repair harness/connector.
Replace ABS/TCS control module.
B4M0535


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7. Diagnostics Chart for Warning Light Circuit Failure

B4M0733A
3. CHECK GROUND SHORT OF HARNESS.
1) Turn ignition switch OFF.
2) Remove No. 18 fuse from fuse and joint box.
3) Disconnect ABS/TCS control module connectors.
4) Measure resistance between ABS/TCS control module
connector and body.
Connector & terminal / Specified resistance:
(P5) No. 1—body/1MΩor more
B4M0405A
4. CHECK GROUND CIRCUIT OF ABS/TCS CONTROL
MODULE.
1) Turn ignition switch OFF.
2) Disconnect connector from ABS/TCS control module.
3) Measure resistance between ABS/TCS control module
connector and body.
Connector & terminal / Specified resistance:
(P4) No. 6—body / 1Ωor less
(P5) No. 5—body / 1Ωor less
(P7) No. 15—body / 1Ωor less
5. CHECK GENERATOR FUNCTION.
1) When the ignition key is at OFF, check the charge warn-
ing light is off.
2) Turn the key ON and ensure the light comes on.
3) Keep the engine running at idle and ensure the light
goes off.
B4M0473A
B4M0395A
6. CHECK INPUT VOLTAGE OF ABS/TCS CONTROL
MODULE.
1) Turn ignition switch OFF.
2) Disconnect ABS/TCS control module connectors.
3) Turn ignition switch ON.
4) Measure voltage between ABS/TCS control module
connector and body.
Connector & terminal / Specified voltage:
(P7) No. 20—body/2Vorless (Engine OFF)
(P7) No. 20—body / 10—14 V (Engine idling)
(P5) No. 1—body / 10—13 V (Engine OFF)
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8. Diagnostics Chart with Trouble Code

12. Phenomena Peculiar to the System
1. WHEN TRAVELING WITH EXTREMELY UNDER
INFLATED TIRES
The TCS is apt to operate (particularly when turning) and,
when it operates, acceleration can become slow*. This
state is not abnormal. Immediately restore the tires to nor-
mal by traveling after releasing the TCS with the TCS OFF
switch.
* Poor acceleration is sometimes caused by the engine
itself. Check whether or not the TCS operating indicator
light (green) comes on to determine that the failure is
caused by the TCS control.
2. WHEN THE T TIRES ARE FITTED
The TCS is apt to operate (particularly when turning) and,
when it operates, acceleration can become slow. This state
is not abnormal. Immediately restore the tires to normal by
traveling after releasing the TCS with the TCS OFF switch.
3. WHEN OPERATING THE TCS CONTINUOUSLY ON
A SLOPE IMPOSSIBLE TO CLIMB OR IN STACK
S TAT E
When operating the TCS for a long time, it can be auto-
matically turned off (the OFF indicator light will come on),
stopping braking. This state is not abnormal. It automati-
cally resets by stopping and leaving the vehicle.
4. WHEN HEAVY LOAD IS PLACED ON THE BRAKES
If service brakes are used too often when descending a
long slope, heavy load can be placed on the brakes. To
prevent this problem, the TCS is automatically turned off
(the OFF indicator light will come on). This state is not
abnormal. Stop the vehicle and leave it in the same way as
step 3, it automatically resets.
5. KICKBACK TO THE BRAKE PEDAL WHEN THE
ABS IS OPERATING
Compared with ABS of the AWD model system, pedal kick-
back with large amplitude of vibration and long cycle can
be felt. This is caused by the difference in system configu-
ration and, therefore, not abnormal. If you receive an
inquiry from your clients, fully explain this point.
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12. Phenomena Peculiar to the System

B: CHECK LIST FOR INTERVIEW
Check the following items about the vehicle’s state.
1. THE STATE OF THE WARNING LIGHTS
a. ABS warning light

1Is always on.2Sometimes comes on.3Comes on only once.4Does not come on.
When/how long does it come on?
Ignition key
position
1Lock2Acc3On (before starting engine)4Start5On after starting (Engine: run)
6On after starting (Engine: stop)
Timing
1Immediately after ignition is on.2Immediately after ignition starts.
3When advancing (Speedmiles/h,miles/h)4While traveling at a constant speed (Speedmiles/h)
5When decelerating (Speedmiles/h,miles/h)
6When turning (To right, to left, steering angledeg., steering timesec)
7When moving other electrical parts (Part name:, Operating condition)
2. SYMPTOMS
ABS operating
condition1Performs no work.2Operates only when abruptly applying brakes. (Conditions: vehicle speedmiles/h, how to step
on brake pedal)
3Operating time (sec., etc.)4Operating noise (Produced/Not produced)
5What kind of noise? (Knock, gong gong, bong, buzz, gong gong buzz, etc.)
6Reaction force of brake pedal (Stick, pressed down once with a clunk, pressed and released, etc.)
Behavior of
vehicle
1Directional stability cannot be obtained or steering arm refuses to work when applying brakes (vehicle turns to right, turns
to left, spins, etc.).
2Directional stability cannot be obtained or steering arm refuses to work when accelerating (vehicle turns to right, turns to
left, spins, etc.).
3Brakes are out of order (braking distance is long, brakes lock or drag, pedal stroke is long, pedal sticks, etc.).
4Poor acceleration (fails to accelerate, engine stalls, etc.).
5Vibration, abnormal noise (operating noise is loud, noise is produced during operation from the front of vehicle (right, left)
(tones:), noise is produced during operation from the rear of vehicle (tones:, others)
6Other phenomena (concrete symptoms)
3. CONDITIONS UNDER WHICH TROUBLE OCCURS
Environment1Weather (fine, cloudy, rain, snow, etc.)
2Ambient temperature (°C/°F)
3Road (urban area, suburbs, highway, general road, ascending slope, descending slope, paved road, gravel road, muddy
road, sandy place, etc.)
4Road surface (dry, wet, new-fallen snow, compressed snow, frozen slope, etc.)
Conditions
1Brakes (decelerationg, continuous/intermittent)2Accelerator (accelerationg, continuous/intermittent)
3Travel speed (miles, advancing, accelerating, reducing speed, low speed, turning, etc.)
4Condition of tire of each wheel (air pressure, degree of wear, whether or not genuine parts are used, whether
or not chain is passed around tires, whether or not T tire is used.) others ()
5Condition of suspension alignment ()
6Loading state ()
4. REPAIRED PARTS ARE USED OR NOT
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6. Diagnostics Chart for On-board Diagnosis System

7. Diagnostics Chart for ABS Warning
Light Circuit and Diagnosis Circuit
Failure
A: ABS WARNING LIGHT DOES NOT COME
ON.
DIAGNOSIS:

ABS warning light circuit is open or shorted.
TROUBLE SYMPTOM:

When ignition switch is turned ON (engine OFF), ABS
warning light does not come on.
7A1.Check if other warning lights turn on.
7A2.Check ABS warning light bulb.
7A3.Check wiring harness.
7A4.Check battery short of relay box.
7A5.Check poor contact in connector between
combination meter and ABSCM.




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7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

WIRING DIAGRAM:
B4M1034
7A1CHECK IF OTHER WARNING LIGHTS
TURN ON.
Turn ignition switch to ON (engine OFF).
: Do other warning lights turn on?
: Go to step7A2.
: Repair combination meter.
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7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B: ABS WARNING LIGHT DOES NOT GO
OFF.
DIAGNOSIS:

ABS warning light circuit is open or shorted.
TROUBLE SYMPTOM:

When starting the engine and while ABS warning light is
kept ON.
7B1.Check installation of ABSCM connector.
7B2.Check generator.
7B3.Check battery terminal.
7B4.Check power supply of ABSCM.
7B5.Check ground circuit of ABSCM.
7B6.Check wiring harness.
7B7.Check relay box.
7B8.Check valve relay.
7B9.Check hydraulic control unit.
7B10.Check diagnosis terminal.
7B11.Check diagnosis line.
7B12.Check poor contact in ABSCM connector.











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7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

B4M0430
7B2
CHECK GENERATOR.
1) Start the engine.
2) Idle the engine.
3) Measure voltage between generator and chassis
ground.
: Terminal
Generator B terminal (+)—Chassis ground
():
Is voltage 10—15 V?
: Go to step7B3.
: Repair generator.
7B3
CHECK BATTERY TERMINAL.
Turn ignition switch to OFF.
: Is there poor contact at battery terminal?
: Repair battery terminal.
: Go to step7B4.
B4M0796A
7B4
CHECK POWER SUPPLY OF ABSCM.
1) Disconnect connector from ABSCM.
2) Start engine.
3) Idle the engine.
4) Measure voltage between ABSCM connector and chas-
sis ground.
: Connector & terminal
(F49) No. 28 (+)—Chassis ground ():
Is voltage 10—15 V?
: Go to step7B5.
: Repair ABSCM power supply circuit.
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7. Diagnostics Chart for ABS Warning Light Circuit and Diagnosis Circuit Failure

When ABS warning light illuminates, read and record
trouble code indicated by ABS warning light.
B: CHECK LIST FOR INTERVIEW
Check the following items about the vehicle’s state.
1. THE STATE OF THE ABS WARNING LIGHT
ABS warning light
comes on.Always
Sometimes
Only once
Does not come on

When /how long does it come on?:
Ignition key positionLOCK
ACC
ON (before starting engine)
START
On after starting (Engine is running)
On after starting (Engine is stop)
TimingImmediately after ignition is ON.
Immediately after ignition starts.
When advancing km/h to km/h
MPH to MPH
While traveling at a constant speed km/h MPH
When decelerating km/h to km/h
MPH to MPH
When turning to right Steering angle : deg
Steering time : sec
When turning to left Steering angle : deg
Steering time : sec
When moving other electrical parts

Parts name :

Operating condition :
2. SYMPTOMS
ABS operating
conditionPerforms no work.
Operates only when abruptly applying brakes. Vehicle speed : km/h
MPH

How to step on brake pedal :
a) Operating time :sec
b) Operating noise :Produce /Does not produce

What kind of noise?Knock
Gong gong
Bong
Buzz
Gong gong buzz
Others :
c) Reaction force of brake pedal
Stick
Press down once with a clunk
Press and released
Others :
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6. Diagnostics Chart for On-board Diagnosis System