1996 TOYOTA LAND CRUISER Starting circuit

V07268
VIBRATION METHOD: When vibration seems to be the major cause.
CONNECTORS
WIRE HARNESS
PARTS AND SENSOR 1
Slightly shake the connector vertically and horizontally.
Slightly shake the wire harness vertically and horizontally.
The connector joint, fulcrum of the vibration, and body
through portion are the major areas to be checked thorough-
ly.
Apply slight vibration with a finger to the part of the sensor
considered to be the pr oblem cause and check that the mal-
function occurs. Shake Slightly
Swing SlightlyVibrate Slightly
HINT:
Applying strong vibration to relays may result in open relays.
IN−22
−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 LAND CRUISER (RM451U)
3. SYMPTOM SIMULATION
The most dif ficult case in troubleshooting is when there are no problem symptoms occurring. In such\
cases,
a thorough customer problem analysis must be carried out, then simulate \
the same or similar conditions and
environment in which the problem occurred in the customer’s vehicle. No matter how much experience a
technician has, or how skilled he may be, if he proceeds to troubleshoot without c\
onfirming the problem
symptoms he will tend to overlook something important in the repair operation an\
d make a wrong guess
somewhere, which will only lead to a standstill. For example, for a problem which only occurs \
when the en-
gine is cold, or for a problem which occurs due to vibration caused by the road during\
driving, etc., the prob-
lem can never be determined so long as the symptoms are confirmed with t\
he engine hot condition or the
vehicle at a standstill. Since vibration, heat or water penetration (moisture) is l\
ikely cause for problem which
is difficult to reproduce, the symptom simulation tests introduced here are ef\
fective measures in that the ex-
ternal causes are applied to the vehicle in a stopped condition.
Important Points in the Symptom Simulation Test:
In the symptom simulation test, the problem symptoms should of course be c\
onfirmed, but the problem area
or parts must also be found out. To do this, narrow down the possible problem circuits according to the symp-
toms before starting this test and connect a tester beforehand. After that, \
carry out the symptom simulation
test, judging whether the circuit being tested is defective or normal and also confirming the \
problem symp-
toms at the same time. Refer to the problem symptoms table for each syst\
em to narrow down the possible
causes of the symptom.
FI2331
FI2332
FI2330
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DI5OY−03
−
DIAGNOSTICS ENGINE
DI−19
1996 LAND CRUISER (RM451U)
PROBLEM SYMPTOMS TABLE
When the malfunction code is not confirmed in the DTC check and the problem \
still can not be confirmed
in the basic inspection, then proceed to this step and perform troubleshooting according to the numbered
order given in the table below.
SymptomSuspect AreaSee page
Engine does not crank (Does not start)1. Starting systemST−16
No initial combustion (Does not start)1. ECM power source circuit
2. Fuel pump control circuitDI−11 0
DI−11 5
No complete combustion (Does not start)1. Fuel pump control circuitDI−11 5
Engine cranks normally (Difficult to start)
1. Starter signal circuit
2. Fuel pump control circuit
3. CompressionDI−103
DI−11 5 EM−3
Cold engine (Difficult to start)1. Starter signal circuit
2. Fuel pump control circuitDI−103DI−11 5
Hot engine (Difficult to start)
1. Starter signal circuit
2. Fuel pressure control circuit
3. Fuel pump control circuitDI−103
DI−125DI−11 5
High engine idle speed (Poor idling)1. A/C signal circuit
2. ECM power source circuitAC−5
DI−11 0
Low engine idle speed (Poor idling)1. A/C signal circuit
2. Fuel pump control circuitAC−5
DI−11 5
Rough idling (Poor idling)1. Compression
2. Fuel pump control circuitEM−3
DI−11 5
Hunting (Poor idling)1. ECM power source circuit
2. Fuel pump control circuitDI−11 0
DI−11 5
Hesitation/Poor acceleration (Poor driveability)1. Fuel pump control circuit
2. A/T faultyDI−11 5
DI−147
Surging (Poor driveability)1. Fuel pump control circuitDI−11 5
Soon after starting (Engine stall)1. Fuel pump control circuitDI−11 5
During A/C operation (Engine stall)1. A/C signal circuit
2. Engine control module (ECM)AC−5
IN−18
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DI−34
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0116 Engine Coolant Temp. Circuit Range/ Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0115 (Engine Coolant Temp. Circuit Malfunction) on page DI−30.
DTC No..DTC Detecting ConditionTrouble Area
P0116
If THW 10°C (50° F), 2 min. or more after starting engine,
engine coolant temp. sensor value is 35 °C (95° F) or less
(2 trip detection logic)
 Engine coolant temp. sensor
 Cooling system
If −7°C (19.4° F)  THW < 10 °C (50° F), 5 min. or more after
starting engine, engine coolant temp. sensor value 35 °C
(95 °F) or less
(2 trip detection logic)
If THW < −7°C (19.4° F), 20 min. or more after starting engine,
engine coolant temp. sensor value is 35 °C (95° F) or less
(2 trip detection logic)
INSPECTION PROCEDURE
HINT:
If DTC P0115 (Engine Coolant Temp. Circuit Malfunction) and P0116 (Engine Coolant Temp. Circuit Range/
Performance) are output simultaneously, engine coolant temp. sensor circuit may be open.
Perform troubleshooting of DTC P0115 first.
1 Are there any other codes (besides DTC P0116) being output?
YES Go to relevant DTC chart.
NO
2 Check thermostat (See page CO−9 ).
NG Replace the thermostat.
OK
Replace engine coolant temp. sensor.
DI5P6−02
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A15825
−
DIAGNOSTICS ENGINE
DI−103
1996 LAND CRUISER (RM451U)
DTC P1500 Starter Signal Circuit Malfunction
CIRCUIT DESCRIPTION
When the engine is cranked, the intake air flow is slow, so fuel vaporization is poor. A rich mixture is therefore
necessary in order to achieve good startability. While the engine is being cranked, the battery positive volt-
age is applied to terminal STA of the ECM. The starter signal is mainly used to increase the fuel inj\
ection
volume for the starting injection control and after −start injection control.
WIRING DIAGRAM
DI968−01
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P22216
Pressure RegulatorVSV
ECM
To Fuel Tank
(Return)
From Delivery Pipe Intake
Manifold
P22482
BRFrom BatteryR/B No.2EB
2
2
2
2
EFI Main
22Y−R
Y−R
EB11
REA27R
R−Y
EZ1
VSV for Fuel21
EZ1
Relay
EFI
12 4
3
1B B3
L−R
Pressure Control E7
E4 3
21 FPU
MRLY
ECM
B+
E01
−
DIAGNOSTICS ENGINE
DI−125
1996 LAND CRUISER (RM451U)
Fuel Pressure Control Circuit
CIRCUIT DESCRIPTION
The ECM turns on a VSV (V acuum Switching Valve) to draw the
air into the diaphragm chamber of the pressure regulator if it de-
tects that the temperature of the engine coolant is too high dur-
ing engine starting.
The air drawn into the chamber increases the fuel pressure to
prevent fuel vapor lock at high engine temperature in order to
help the engine start when it is warm.
Fuel pressure control ends approx. 120 sec. after the engine is
started.
WIRING DIAGRAM
DI5PZ−02
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−
DIAGNOSTICS AUTOMATIC TRANSMISSION
DI−149
1996 LAND CRUISER (RM451U)
Harsh engagement (N
→ D)
1. Shift solenoid valve SL circuit
2. ATF temp. sensor circuit
3. Throttle position sensor circuit
4. Park/neutral position switch circuit
5. On −vehicle repair matrix chart
6. Off −vehicle repair matrix chart
7. ECMDI−163
DI−154 DI−35
DI−169 −
−
DI−145
Harsh engagement (Lock −up)
1. Shift solenoid valve SL circuit
2. Throttle position sensor circuit
3. No. 1 vehicle speed sensor circuit
4. No. 2 vehicle speed sensor circuit
5. On −vehicle repair matrix chart
6. Off −vehicle repair matrix chart
7. ECMDI−163 DI−35
DI−87
DI−166 −
−
DI−145
Harsh engagement (Any driving position)
1. Shift solenoid valve SL circuit
2. ATF temp. sensor circuit
3. Throttle position sensor circuit
4. No. 1 vehicle speed sensor circuit
5. No. 2 vehicle speed sensor circuit
6. On −vehicle repair matrix chart
7. Off −vehicle repair matrix chart
8. ECMDI−163
DI−154 DI−35
DI−87
DI−166
−
−
DI−145
Slip or shudder (Forward and reverse)1. On −vehicle repair matrix chart
2. Off −vehicle repair matrix chart−
−
Slip or shudder (A particular position)1. On −vehicle repair matrix chart
2. Off −vehicle repair matrix chart−
−
No engine braking1. On −vehicle repair matrix chart
2. Off −vehicle repair matrix chart−
−
Poor acceleration
1. Throttle position sensor circuit
2. No. 1 vehicle speed sensor circuit
3. No. 2 vehicle speed sensor circuit
4. Shift solenoid valve No. 1 and No. 2 circuit
5. Shift solenoid valve SL circuit
6. On −vehicle repair matrix chart
7. Off −vehicle repair matrix chartDI−35
DI−87
DI−166
DI−157
DI−163 −
−
No kick− down
1. Throttle position sensor circuit
2. Shift solenoid valve No. 1 and No. 2 circuit
3. No. 1 vehicle speed sensor circuit
4. On−vehicle repair matrix chart
5. ECMDI−35
DI−157 DI−87 −
DI−145
No pattern select1. Pattern select switch circuit
2. ECMDI−179
DI−145
No 2nd start
1. Pattern select switch circuit
2. Shift solenoid valve No. 1 and No. 2 circuit
3. ECMDI−179
DI−157
DI−145
Large shift shock or engine stalls when starting off or stopping
1. Shift solenoid valve SL circuit
2. Stop light switch circuit
3. Off −vehicle repair matrix chart
4. ECMDI−163
DI−185 −
DI−145
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DI5Q3−02
−
DIAGNOSTICS SUPPLEMENTAL RESTRAINT SYSTEM
DI−243
1996 LAND CRUISER (RM451U)
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the DTC check, the circuit listed for that code in t\
he table below
(Proceed to the page given for that circuit.).
DTC No.
(See Page)Detection ItemTrouble AreaSRS
Warning Light
Normal
( DI−271 )System normal−OFF
Source voltage dropBattery
 Airbag sensor assemblyON
11
( DI−247 )
Short in squib circuit (to ground)Steering wheel pad (D squib)
 Front passenger airbag assembly (P squib )
 Spiral cable
 Airbag sensor assembly
 Wire harness
ON
12
( DI−254 )
Short in squib circuit (to B+)Steering wheel pad (D squib)
 Front passenger airbag assembly (P squib)
 Spiral cable
 Airbag sensor assembly
 Wire harness
ON
14
( DI−260 )
Open in D squib circuitSteering wheel pad (D squib)
 Spiral cable
 Airbag sensor assembly
 Wire harness
ON
31
( DI−265 )Airbag sensor assembly malfunctionAirbag sensor assemblyON
54
( DI−267 )Open in P squib circuitFront passenger airbag assembly (P squib)
 Airbag sensor assembly
 Wire harness
ON
HINT:
When the SRS warning light remains lit up and the DTC is the normal code\
, this means a source drop
voltage.
This malfunction is not stored in memory by the airbag sensor assembly a\
nd if the power source volt-
age returns to normal, the SRS warning light will automatically go out.
When 2 or more codes are indicated, the codes will be displayed in numer\
al order starting from the
lowest numbered code.
If a code not listed on the chart is displayed, the airbag sensor assemb\
ly is faulty.
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RS0OZ−02
−
SUPPLEMENTAL RESTRAINT SYSTEM SRS AIRBAG
RS−1
1100
Author: Date:
1996 LAND CRUISER (RM451U)
SRS AIRBAG
PRECAUTION
NOTICE:
The LAND CRUISER is equipped with an SRS , which comprises a driver airbag \
and a front pas-
senger airbag. Failure to carry out service operations in the correct sequence could cause the
SRS to unexpectedly deploy during servicing, possibly leading to a serio\
us accident. Further,
if a mistake is made in servicing the SRS, it is possible the SRS may fail to\
operate when re-
quired. Before performing servicing (including removal or installation \
of parts, inspection or
replacement), be sure to read the following items carefully, then follow the correct procedure
described in the repair manual.
Malfunction symptoms of the SRS are difficult to confirm, so the DTCs become the mos\
t impor-
tant source of information when troubleshooting. When troubleshooting th\
e SRS, always in-
spect the DTCs before disconnecting the battery.
Even in cases of a minor collision where the SRS does not deploy, the steering wheel pad, front
passenger airbag assembly, and airbag sensor assembly should be inspected (See pages
RS−9 , RS−23 and RS−34 )
Never use SRS parts from another vehicle. When replacing parts, replace them with \
new parts.
Never disassemble and repair the steering wheel pad, front passenger airbag assembly , or air-
bag sensor assembly in order to reuse it.
If the steering wheel pad, front passenger airbag assembly or airbag sen\
sor assembly have
been dropped, or if there are cracks, dents or other defects in the case, br\
acket or connector,
replace them with new ones.
Use a volt/ohmmeter wi th high impedance (10 k Ω/V minimum) for troubleshooting the system’s
electrical circuits.
Information labels are attached to the periphery of the SRS components. Follow the instruc-
tions on the notices.
After work on the SRS is completed, check the SRS warning light (See pa\
ge DI−240).
If the vehicle is equipped with a mobile communication system, refer to the precaution in the
IN section.
CAUTION:
Work must be started after 90 seconds from the time the ignition switch is t\
urned to the ”LOCK”
position and the negative ( −) terminal cable is disconnected from the battery.
(The SRS is equipped with a back− up power source so that if work is started within 90 seconds
of disconnecting the negative ( −) terminal cable of the battery, the SRS may be deployed.)
When the negative (−) terminal cable is disconnected from the battery, the memory of the clock
and audio system will be canceled. So before starting work, make a record o\
f the contents mem-
orized in the audio memory system. When work is finished, reset the audio syst\
ems as they
were before and adjust the clock. To avoid erasing the memory of each memory system, never
use a back−up power supply from outside the vehicle.
Before repairs, remove the airbag sensor if shocks are likely to be applied to the senso\
r during
repairs.
Do not expose the steering wheel pad, front passenger airbag assembly, or airbag sensor as-
sembly directly to hot air or flames.
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