1997 SUBARU LEGACY sensor

B: AUTOMATIC TRANSMISSION
1. ELECTRONIC-HYDRAULIC CONTROL SYSTEM
The electronic-hydraulic control system consists of various
sensors and switches, a transmission control module
(TCM) and the hydraulic controller including solenoid
valves. The system controls the transmission proper
including shift control, lock-up control, overrunning clutch
control, line pressure control and shift timing control. It also
controls the AWD transfer clutch. In other words, the sys-
tem detects various operating conditions from various input
signals and sends output signals to shift solenoids 1, 2 and
3 and duty solenoids A, B and C (a total of six solenoids).
10
2-7ON-BOARD DIAGNOSTICS II SYSTEM
1. General

2. SENSOR
B2M1169D
1Pressure sensor

2Mass air flow sensor

3Engine coolant temperature sensor

4Throttle position sensor
5Knock sensor

6Camshaft position sensor

7Crankshaft position sensor
14
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

B2M0471A
B2M0472A
8Front oxygen sensor

9Rear oxygen sensor (Except 2200 cc California spec.
vehicles)
10Rear oxygen sensor (2200 cc California spec. vehicles)

11Front catalytic converter

12Rear catalytic converter
OBD0018AOBD0019E
16
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

OBD0003F
B2M0430F
1Fuel level sensor

2Fuel temperature sensor (2200 cc AWD except Taiwan spec.
vehicles)
3Fuel tank pressure sensor (2200 cc AWD except Taiwan
spec. vehicles)

4Fuel sub level sensor
18
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

2. SENSOR
OBD0041AOBD0042A
OBD0043AOBD0044A
H2M1145BOBD0653A
1Vehicle speed sensor 1 [AT FWD vehicles]

2Vehicle speed sensor 1 [AT AWD vehicles]

3Vehicle speed sensor 2 [MT vehicles]
4Vehicle speed sensor 2 [AT vehicles]

5ATF temperature sensor [AT vehicles]

6Brake light switch
28
2-7ON-BOARD DIAGNOSTICS II SYSTEM
2. Electrical Components Location

OBD0006F
B2M0433D
B: OBD-II GENERAL SCAN TOOL
1. HOW TO USE OBD-II GENERAL SCAN TOOL
1) Prepare a general scan tool (OBD-II general scan tool)
required by SAE J1978.
2) Open the cover and connect the OBD-II general scan
tool to the data link connector located in the lower portion
of the instrument panel (on the driver’s side), to the lower
cover.
3) Using the OBD-II general scan tool, call up diagnostic
trouble code(s) and freeze frame data.
OBD-II general scan tool functions consist of:
(1) MODE $01: Current powertrain diagnostic data
(2) MODE $02: Powertrain freeze frame data
(3) MODE $03: Emission-related powertrain diagnostic
trouble codes
(4) MODE $04: Clear/Reset emission-related diagnos-
tic information
(5) MODE $05: Oxygen sensor monitoring test results
Read out data according to repair procedures.
(For detailed operation procedures, refer to the OBD-II
General Scan Tool Operation Manual.)
NOTE:
For details concerning diagnostic trouble codes, refer to
the DIAGNOSTIC TROUBLE CODE (DTC) LIST. 2-7 [T10A0], [T11A0].>
H2M1280
2. DATA LINK CONNECTOR (FOR OBD-II GENERAL
SCAN TOOL AND SUBARU SELECT MONITOR)
1) This connector is used both for OBD-II general scan
tools and the Subaru Select Monitor.
2) Terminal No. 4 to No. 6 of the data link connector is
used for the Subaru Select Monitor signal.
CAUTION:
Do not connect any scan tools other than the OBD-II
general scan tools and the Subaru Select Monitor,
because the circuit for the Subaru Select Monitor may
be damaged.
Terminal No. Contents Terminal No. Contents
1 Power supply 9 Blank
2 Blank 10 K line of ISO 9141 CARB
3 Blank 11 Blank
4Subaru Select Monitor signal (ECM to Subaru
Select Monitor)*12 Ground
5Subaru Select Monitor signal (Subaru Select
Monitor to ECM)*13 Ground
6 Subaru Select Monitor clock* 14 Blank
7 Blank 15 Blank
8 Blank 16 Blank
*: Circuit only for Subaru Select Monitor
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2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

3. CURRENT POWERTRAIN DIAGNOSTIC DATA
(MODE $01)
Refers to data denoting the current operating condition of
analog input/output, digital input/output and/or the power-
train system.
A list of the support data and PID (Parameter Identification)
codes are shown in the following table.
PID DataUnit of measure
01 Number of emission-related powertrain trouble codes and MIL status ON/OFF
03 Fuel system control status—
04 Calculated engine load value%
05 Engine coolant temperature°C
06 Short term fuel trim%
07 Long term fuel trim%
0B Intake manifold absolute pressurekPa
0C Engine revolutionrpm
0D Vehicle speedkm/h
0E Ignition timing advance°
10 Air flow rate from mass air flow sensor g/sec
11 Throttle valve opening angle%
13 Check whether oxygen sensor is installed.—
14 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor—bank 1 V and %
15 Oxygen sensor output voltage and short term fuel trim associated with oxygen sensor—bank 2 V and %
1C On-board diagnosis system—
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruc-
tion manual to access generic OBD-II PIDs (MODE $01).
33
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System

6. CLEAR/RESET EMISSION-RELATED DIAGNOSTIC
INFORMATION (MODE $04)
Refers to the mode used to clear or reset emission-related
diagnostic information (OBD-II trouble diagnostic informa-
tion).
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruc-
tion manual to clear or reset emission-related diagnostic
information (MODE $04).
7. OXYGEN SENSOR MONITORING TEST RESULTS
(MODE $05)
Refers to the mode using oxygen sensor output data while
the on-board diagnosis system is performing diagnosis on
the oxygen sensor.
A list of the support oxygen sensor output data and test ID
(identification) are shown in the following table.
Test ID DataUnit of measure
01 Rich to lean sensor threshold voltage (constant) V
02 Lean to rich sensor threshold voltage (constant) V
03 Low sensor voltage for switch time calculation (constant) V
04 High sensor voltage for switch time calculation (constant) V
05 Rich to lean sensor switch time (calculated) sec.
06 Lean to rich sensor switch time (calculated) sec.
07 Minimum sensor voltage for test cycle (calculated) V
08 Maximum sensor voltage for test cycle (calculated) V
NOTE:
Refer to OBD-II general scan tool manufacturer’s instruc-
tion manual to access oxygen sensor monitoring test
results (MODE $05).
35
2-7ON-BOARD DIAGNOSTICS II SYSTEM
3. Diagnosis System