input device usage on specific models, see appropriate wiring diagram
in M - WIRING DIAGRAMS.
Air Conditioner Switch
When A/C is turned on, signal is sent to ECU. With engine at
idle, ECU increases idle speed through Idle Speed Control (ISC) motor.\
Airflow Sensor
Incorporated in airflow sensor assembly, airflow sensor is a
Karmen Vortex-type sensor which measures intake airflow rate.
Intake air flows through tunnel in airflow sensor assembly.
Airflow sensor transmits radio frequency signals across direction of
incoming airflow, downstream of vortex. Intake air encounters vortex,
causing turbulence in tunnel.
Turbulence disrupts radio frequency, causing variations in
transmission. Airflow sensor converts frequency transmitted into a
proportionate electrical signal which is sent to ECU.
Airflow Sensor Assembly
Mounted inside air cleaner, incorporates airflow sensor,
atmospheric pressure sensor and intake air temperature sensor.
Atmospheric (Barometric) Pressure Sensor
Incorporated in the airflow sensor assembly, converts
atmospheric pressure to electrical signal which is sent to ECU. ECU
adjusts air/fuel ratio and ignition timing according to altitude.
Coolant Temperature Sensor
Converts coolant temperature to electrical signal for use by
ECU. ECU uses coolant temperature information for controlling fuel
enrichment when engine is cold.
Crankshaft Angle & TDC Sensor Assembly
Assembly is located in distributor on SOHC engines. On DOHC
engines, which use Direct (or Distributorless) Ignition System (DIS)\
,
assembly is separate unit mounted in place of distributor. Assembly
consists of triggering disc (mounted on shaft) and stationary optical
sensing unit. Camshaft drives shaft, triggering optical sensing unit.
ECU determines crank angle and TDC based on signals received from
optical sensing unit.
Detonation Sensor (Turbo Only)
Located in cylinder block, senses engine vibration during
detonation (knock). Sensor converts vibration into electrical signal.
ECU retards ignition timing based on this signal.
Engine Speed (Tach Signal)
ECU uses ignition coil tach signal to determine engine speed.
Idle Position Switch
On all DOHC engines and Sigma 3.0L, idle position switch is
separate switch mounted on throttle body. On all other models, idle
position switch is incorporated in ISC motor or throttle position
sensor, depending on vehicle application. When throttle valve is
closed, switch is activated. When throttle valve is at any other
position, switch is deactivated. This input from idle position switch
is used by ECU for controlling fuel delivery time during deceleration.
Ignition Timing Adjustment Terminal
Used for adjusting base ignition timing. When terminal is
grounded, ECU timing control function is by-passed, allowing base
timing to be adjusted.
TR AN SFE R C ASE
1991 M it s u bis h i M onte ro
1991-94 TRANSFER CASES
Mitsubishi
Dodge; Ram-50
Mitsubishi; Pickup, Montero
APPLICATION
TRANSFER CASE APPLICATIONS TABLE \
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Application ( 1) Transmission Model
Dodge
1991-93 Ram-50 (2.4L) .......................... V5M21-1
1991-93 Ram-50 (3.0L M/T) ...................... V5MT1-2
1991-93 Ram-50 (3.0L A/T) ...................... V4AC1-2
Mitsubishi
1991-92 Pickup ................................. V5MT1-2
1991 Montero (M/T) ............................. V5MT1-2
1991 Montero (A/T) ............................. V4AW2-2
1992 Montero (M/T) ......................... ( 2) V5MT1-3
1992 Montero (A/T) ......................... ( 2) V4AW2-3
1993-94 Montero (M/T) ...................... ( 2) V5MT1-2
1993-94 Montero (A/T) ........................ ( 2) R4AC1
( 1) - Transfer case is indicated by a -2 or -3 following the
transmission model number.
( 2) - Transfer cases for Montero are identical for automatic and
manual transmission models.
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DESCRIPTION
Transfer case is a part-time, 2-speed unit with a 3-piece
aluminum case. Transfer case has a floor-mounted shifter and integral
speedometer gear. In Montero a Viscous Coupling Unit (VCU) and center
differential allows 2WD-to-4WD shifting at speeds under 62 MPH and
full-time 4WD operation.
WARNING: When battery is disconnected, vehicles equipped with
computers may lose memory data. When battery power is
restored, driveability problems may exist on some vehicles.
These vehicles may require a relearn procedure. See the
COMPUTER RELEARN PROCEDURES article in the GENERAL
INFORMATION section.
TESTING
4WD INDICATOR CONTROL UNIT (MONTERO)
The 4WD indicator control unit is located behind radio or CD
player. Remove 4WD indicator control unit and disconnect harness.
Backprobe harness connector and measure voltage between terminal No. 8
(ground) and each respective terminal. Compare test results with
chart. See Fig. 1.
DETECTION SWITCH
OVERDRIVE SWITCH ................................. 3 (A 8)
PARKING BRAKE SWITCH ............................ 6 (A 21)
POWER TRANSISTOR ................................. 2 (D 4)
POWER WINDOWS .............................. 7 (B-E 24-26)
RADIO (PARTIAL) ............................... 3 (D-E 10)
REAR BLOWER SWITCH .............................. 4 (D 12)
REAR WIPER .................................... 5 (D-E 16)
SEAT BELT WARNING TIMER ......................... 5 (D 18)
STARTER .......................................... 1 (C 3)
STOP LIGHT SWITCH ..................... 4 (E 13), 5 (C 16)
SUB FUSE LINKS ................................... 1 (A 3)
SUNROOF ...................................... 7 (A 24-25)
WIPER SWITCH .................................. 5 (A-B 19)
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WIRING DIAGRAMS