Page 29 of 1033

TCM FUNCTION
The function of the TCM is to:
+Receive input signals sent from various switches and sensors.
+Determine required line pressure, shifting point, lock-up operation, and engine brake operation.
+Send required output signals to the respective solenoids.
INPUT/OUTPUT SIGNAL OF TCM
Sensors and solenoid valves Function
InputPNP switch Detects select lever position and sends a signal to TCM.
Accelerator position sensor Detects throttle valve position and sends a signal to TCM.
Accelerator position switch
(Off accel)Detects throttle valve's fully-closed position and sends a signal to TCM.
Accelerator position switch
(Full accel)Detects a throttle valve position of greater than 1/2 of full throttle and sends a
signal to TCM.
Engine speed signal From ECM.
A/T fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM.
Revolution sensor Detects output shaft rpm and sends a signal to TCM.
Vehicle speed sensorUsed as an auxiliary vehicle speed sensor. Sends a signal when revolution sen-
sor (installed on transmission) malfunctions.
Overdrive control switch
A/T mode switchSends a signal, which prohibits a shift to ªD
4º (overdrive) position, to the TCM.
OutputShift solenoid valve A/BSelects shifting point suited to driving conditions in relation to a signal sent from
TCM.
Line pressure solenoid valveRegulates (or decreases) line pressure suited to driving conditions in relation to
a signal sent from TCM.
Torque converter clutch solenoid valveRegulates (or decreases) lock-up pressure suited to driving conditions in relation
to a signal sent from TCM.
Overrun clutch solenoid valveControls an ªengine brakeº effect suited to driving conditions in relation to a sig-
nal sent from TCM.
O/D OFF indicator lamp
SPORT indicator lampShows TCM faults, when A/T control components malfunction.
OVERALL SYSTEM
Control System (Cont'd)
AT-1027
Page 68 of 1033

Vehicle Speed SensorzMTR
DESCRIPTION
The vehicle speed sensorzMTR is built into the speedometer
assembly. The sensor functions as an auxiliary device to the
revolution sensor when it is malfunctioning. The TCM will then
use a signal sent from the vehicle speed sensorzMTR.
ON BOARD DIAGNOSIS LOGIC
Diagnostic trouble code Malfunction is detected when ...Check items
(Possible cause)
:
VHCL SPEED SENzMTR
TCM does not receive the proper volt-
age signal from the sensor.+Harness or connectors
(The sensor circuit is open or
shorted.)
+Vehicle speed sensor
:
2nd judgement flicker
SELF-DIAGNOSIS CODE CONFIRMATION
PROCEDURE
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
1) Start engine.
2) Select ªSELF-DIAG RESULTSº mode for A/T with
CONSULT-II.
3) Drive vehicle under the following conditions:
Selector lever in ªDº position and vehicle speed higher
than 20 km/h (12 MPH).
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Start engine.
2) Drive vehicle under the following conditions:
Selector lever in ªDº position and vehicle speed higher
than 20 km/h (12 MPH).
3) Perform self-diagnosis.
Refer to SELF-DIAGNOSTIC PROCEDURE (Without
CONSULT-II), AT-1029.
SAT237J
SAT014K
SAT807H
TROUBLE DIAGNOSIS FOR VHCL SPEED SENzMTR
AT-1066
Page 765 of 1033
Removal and Installation
CAUTION:
As the internal mechanism of the idler gear must first of all,
and always, be set by a bolt when removing the timing chain
before removing the fuel injection pump and timing gear,
follow the procedures on EM-1039, ªRemoval of timing
chain after setting idler gearº, ªElectronic controlled fuel
injection pumpº.
+This chapter will deal with the summary of removing the tim-
ing chain before removing the camshaft and cylinder head.
Removal
1. Remove the following parts.
+Engine cover
+Intercooler
+Air inlet pipe
+Throttle body
+Rocker cover
+Spill tube
+Coolant (Drain)
+Radiator upper hose
+Water outlet
+Radiator shroud
+Cooling fan
+Auxilary belt
FEM003
TIMING CHAINZD
EM-1027
Page 778 of 1033

Removal
1. Remove the following parts.
+Undercover
+Engine oil (Drain)
+Engine coolant (Drain)
+Engine cover
+Intercooler
+Air inlet pipe
+Air cleaner case
+Throttle body
+Swirl and intake air control valve control solenoid valve and
bracket
+Vacuum tank
+Glow plate
+Rocker cover
+Spill tube
+Radiator shrouds (Rear and Lower)
+Cooling fan
+Radiator hose (Upper and Lower)
+Auxiliary belt and auto tensioner.
2. Remove the alternator.
3. Remove the A/C compressor and bracket with piping con-
nected. Move and support it at the LH side of engine bay with
a rope to avoid putting load on piping.
Refer to HA section in Nissan Service Manual (Supplement
I: Publication No. SM0E-Y61AE0E.)
4. Remove the chain cover, timing chain and other parts in
connection.
Before removing timing chain, remove injection pump
sprocket with No.1 cylinder being positioned at TDC. Refer
to the figure.
Refer to ªTIMING CHAINº, EM-1027.
CAUTION:
After removing timing chain, never rotate crankshaft, or the
piston will push the valve up and damage the valve.
+Do not paint the match mark on the timing chain beforehand
as the No. 1 cylinder is set at the TDC during assembly.
5. Remove the TDC sensor.
CAUTION:
+Do not drop or hit the sensor.
+Store in a clean place free of iron filings, etc.
+Do not place near any magnetic equipment.
6. Remove the water pump and its stud bolts.
Refer to ªWATER PUMPº in LC section.
7. Remove the water inlet.
SEM376G
TIMING GEARZD
EM-1040
Page 791 of 1033
Removal and Installation
Removal
1. Remove the following. (Refer to corresponding chapter for
detailed auxiliary work.)
+Drain coolant
+Rocker cover
+Injection tube
+Spill tube
+High pressure injection nozzle assembly
+Timing chain
+Camshaft
+Catalytic converter
+Turbocharger assembly
+Exhaust manifold
2. Remove mounting bolts of the gear case and water pump as
shown by arrows in the figure.
3. Remove oil return pipe from the rear side of cylinder head.
4. Remove intake manifold.
SEM359G
FEM054
CYLINDER HEADZD
EM-1053