speed sensor SUBARU LEGACY 1995 Service Service Manual

OBD0145A
2
CHECK FRONT OXYGEN SENSOR DATA.
1) Turn ignition switch to OFF.
2) Connect the Subaru Select Monitor or the OBD-II gen-
eral scan tool to data link connector.
3) Start engine and Turn the Subaru Select Monitor and
the OBD-II general scan tool switch to ON.
4) Warm-up the engine until coolant temperature is above
70°C (160°F) and keep the engine speed at 2,000 rpm to
3,000 rpm for one minute.
5) Read data on Subaru Select Monitor or the OBD-II gen-
eral scan tool.
OBD0206
OBD0207

Subaru Select Monitor
Designate mode using function key.
Function mode: F14 or F15

F14: Front oxygen sensor max. output signal is indi-
cated.

F15: Front oxygen sensor min. output signal is indi-
cated.
: Is the difference of voltage between F14 and
F15 0.1 V, or less?
: Go to step 3.
: Replace front oxygen sensor.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
175
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11. Diagnostics Chart with Trouble Code

1
CHECK DTC P0130 ON DISPLAY.
: Check that Subaru Select Monitor or the
OBD-II general scan tool shows P0130.
: Go to step 2.
: Go to step 3.
2
CHECK FAILURE CAUSE OF P0130.
Perform the step 1 of DTC P0130.
: Is the failure cause of P0130 in the fuel sys-
tem?
: Check fuel system. In this case, inspection of
P0136 is not necessary.
: Go to step 3.
OBD0145A
3
CHECK REAR OXYGEN SENSOR DATA.
1) Turn ignition switch to OFF.
2) Connect Subaru Select Monitor or OBD-II general scan
tool to data link connector.
3) Start the engine, and turn Subaru Select Monitor or
OBD-II general scan tool switch to ON.
4) Warm-up the engine until engine coolant temperature is
above 70°C (160°F), and keep the engine speed at 2,000
rpm to 3,000 rpm for two minutes.
OBD0225
5) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F16

F16: Rear oxygen sensor output signal is indicated.
: Is the indicated data fluctuate?
: Go to step 5.
: Go to next.
: Is the indicated data fixed at 0.3±0.1 V?
: Go to step 4.
: Replace rear oxygen sensor.

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
188
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0145A
5
CHECK MASS AIR FLOW SENSOR.
1) Turn ignition switch to OFF.
2) Connect the Subaru Select Monitor or the OBD-II gen-
eral scan tool to data link connector.
3) Start the engine and warm-up engine until coolant tem-
perature is greater than 60°C (140°F).
OBD0616
4) Read data on Subaru Select Monitor or OBD-II general
scan tool.

Subaru Select Monitor
Designate mode using function key.
Function mode: F47

F47: Mass air flow is shown on display.
: Is the voltage within the specifications
shown in the following table?
Engine speed Specified value
Idling 1.9—3.6 (g/sec)
2,500 rpm 7.0—14.8 (g/sec)
: Replace mass air flow sensor.
: Contact with SOA service.
Note: Inspection by DTM is required.
Probable cause: Deterioration of plural parts

OBD-II general scan tool
For detailed operation procedures, refer to the OBD-II Gen-
eral Scan Tool Instruction Manual.
202
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0340
AG: DTC P0500
—VEHICLE SPEED SENSOR MALFUNCTION
(VSP)—
DESCRIPTION:

The speedometer system is an electric type; it uses no
speedometer cable and drives the speedometer according
to electric pick-up sensor (vehicle speed sensor 2).
The speed sensor 2 is installed on the transmission. The
speed sensor 2 sends the vehicle speed signal (8 pulses
per one turn of speed sensor driven shaft) to the speed
detection circuit in the speedometer where this signal pulse
wave is regulated.
The regulated pulse signal (4 pulses per one turn of speed
sensor driven shaft) is sent to the speedometer drive cir-
cuit and odometer (trip meter) drive circuit.
The output signal from vehicle speed detection circuit is
also used in ECM, TCM, etc.
B6H0022A
B6H0021A

The speed sensor 2 consists of a magnetic resistance
element, magnet ring, driven shaft, spring, etc.
As the driven key rotates, the magnet turns to change the
magnetic field of the coil.
The coil generates power corresponding to a change in the
magnetic field.
One turn of the driven key in the vehicle speed sensor 2
sends 8 pulses of AC signal to the combination meter.
DTC DETECTING CONDITION:

Immediately at fault recognition
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11. Diagnostics Chart with Trouble Code

1CHECK SPEEDOMETER OPERATION IN COM-
BINATION METER.
: Check normal operation of speedometer.
: Check speedometer and vehicle speed sensor
.
: Go to step 2.
OBD0349A
2
CHECK HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from TCM.
3) Turn ignition switch to ON.
4) Measure voltage between ECM and body.
: Connector & terminal
(B84) No. 57—Body / 2 V, or more
: Check the following and repair if necessary.

Open circuit of harness between ECM connector and
combination meter connector

Poor contact in ECM connector

Poor contact in combination meter connector

Poor contact in coupling connector (B37)
: Go to step 3.
OBD0351A
3
CHECK HARNESS.
1) Turn ignition switch to OFF.
2) Disconnect connector from ECM.
3) Measure resistance of harness between ECM connec-
tor and body.
: Connector & terminal
(B84) No. 57—Body / 10Ω, or less
: Repair short circuit of harness between ECM con-
nector and combination meter connector.
: Repair poor contact in ECM connector.
255
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0380
AO: DTC P0710
—TRANSMISSION FLUID TEMPERATURE
SENSOR CIRCUIT MALFUNCTION (ATF)—
H2M1145
DESCRIPTION:
This sensor is mounted to the control valve in the transmis-
sion. It detects temperature change as an analog electrical
signal. The output characteristics of the sensor are shown
in the illustration.
DTC DETECTING CONDITION:

Two consecutive trips with fault
TROUBLE SYMPTOM:

No shift up to 4th speed (after engine warm-up)

No lock-up occurs. (after engine warm-up)

Excessive shift shock
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

OBD0392
AP: DTC P0720
—OUTPUT SPEED SENSOR (VEHICLE
SPEED SENSOR 1) CIRCUIT MALFUNCTION
(ATVSP)—
OBD0393A
DESCRIPTION:
[FWD model]

The vehicle speed sensor 1 is mounted to the transmis-
sion case (at the rear side of the case). The sensor outputs
a pulse signal which is transmission to the TCM where it is
converted to vehicle speed.

Vehicle speed sensor 1 on FWD model detects front-
wheel speed.
OBD0394A
[AWD]

The vehicle speed sensor 1 (output shaft rotation sen-
sor) is mounted to the extension case (from the outside of
the case). The sensor outputs a pulse signal which is trans-
mitted to the TCM where it is converted to vehicle speed.

The transfer clutch drum is connected directly to the rear
wheel driving propeller shaft. Vehicle speed sensor 1 on
the AWD model defects rear-wheel speed.
DTC DETECTING CONDITION:

Two consecutive trips with fault
TROUBLE SYMPTOM:

No shift or excessive tight corner“braking”
281
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11. Diagnostics Chart with Trouble Code

1.Check harness connector between TCM and
vehicle speed sensor 1.
2.Check vehicle speed sensor 1.
3.Check input signal for TCM.
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES. [T3D0] and [T3E0].>
WIRING DIAGRAM:
B2M0628
NOTE:
For the diagnostic procedure on vehicle speed sensor 1
circuit, refer to“3-2 [T7M0]”.


282
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code

DTC DETECTING CONDITION:

Two consecutive trips with fault
TROUBLE SYMPTOM:

Shift point too high or too low; engine brake not effected
in“3”range; excessive shift shock; excessive tight corner
“braking”
1.Check any other DTC (besides DTC P0731,
P0732, P0733, P0734) on display.
2.Check throttle position sensor circuit. “3-2 [T7L0]”.>
3.Check vehicle speed sensor 1 circuit. “3-2 [T7M0]”.>
4.Check vehicle speed sensor 2 circuit. “3-2 [T7N0]”.>
5.Check engine speed input circuit. [T7I0]”.>
CAUTION:
After repair or replacement of faulty parts, conduct
CLEAR MEMORY and INSPECTION MODES. [T3D0] and [T3E0].>




286
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11. Diagnostics Chart with Trouble Code

2CHECK THROTTLE POSITION SENSOR CIR-
CUIT.
: Is there any trouble in throttle position sen-
sor circuit?
: Repair or replace throttle position sensor circuit.
: Go to step 3.
3
CHECK VEHICLE SPEED SENSOR 1 CIRCUIT.
: Is there any trouble in vehicle speed sensor
1 circuit?
: Repair or replace vehicle speed sensor 1 circuit.
: Go to step 4.
4
CHECK VEHICLE SPEED SENSOR 2 CIRCUIT.
: Is there any trouble in vehicle speed sensor
2 circuit?
: Repair or replace vehicle speed sensor 2 circuit.
: Go to step 5.
5
CHECK ENGINE SPEED INPUT CIRCUIT.
: Is there any trouble in engine speed input
circuit?
: Repair or replace engine speed input circuit.
: Go to next.
: Is there poor contact in TCM connector?
: Repair poor contact in TCM connector.
: Go to next.
: Is there any mechanical trouble in automatic
transmission?
: Repair or replace automatic transmission.
: Replace TCM with a new one.
288
2-7ON-BOARD DIAGNOSTICS II SYSTEM
11. Diagnostics Chart with Trouble Code