V08425
LOCKKNK
E6 Connector
(a) Remove the glove compartment (See page SF− 68).
(b) Disconnect the E6 connector from the ECM.
INSPECTION PROCEDURE
Replace knock sensor.
1 Check continuity between terminal KNK of ECM connector and body ground.
OK:
Check knock sensor (See page SF−61).
Measure
the resistance between terminal KNK of the ECM connec-
tor and body ground.
Resistance: 1 MΩ or higher
Connector being checked is connected.
Indicates the condition of the connector of ECU during the check.
PREPARATION:
CHECK:
2
Go to step 3.
OK OK
NG
Indicates the position of the ignition switch during the check.
Check from the connector back side.
(with harness)
Ignition Switch LOCK (OFF) Ignition Switch START
LOCKIgnition Switch ONIgnition Switch ACC
START ON
ACC
Indicates the place to check the voltage or resistance.
Indicates the connector position to checked, from the front or back side.
Connector being checked is disconnected.
Check from the connector front side. (without harness)
In this case, care must be taken not to bend the terminals.
E6 Connector
KNK Wire Harness
E6 Connector
KNK
A00255
AB0117
A00265
Inspection Procedure
Use the inspection procedure to determine if
the circuit is normal or abnormal, and, if it is
abnormal, use it to determine whether the
problem is
located in the sensors, actuators,
wire harness or ECU.
−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN−27
1996 LAND CRUISER (RM451U)
(2)
(2)
~
~
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
FI0048
FI0047
FI0046
IN05X−13
IN−28−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 LAND CRUISER (RM451U)
HOW TO USE THE DIAGNOSTIC
CHART AND INSPECTION
PROCEDURE
1. CONNECTOR CONNECTION AND TERMINAL IN- SPECTION
For troubleshooting, diagnostic trouble code charts or
problem symptom table are provided for each circuit with
detailed inspection procedures on the following pages.
When all the component parts, wire harnesses and con-
nectors of each circuit except the ECU are found to be
normal in troubleshooting, then it is determined that the
problem is in the ECU. Accordingly, if diagnosis is per-
formed without the problem symptoms occurring, refer to
Step 8 to replace the ECU. So always confirm that the
problem symptoms are occurring, or proceed with inspec-
tion while using the symptom simulation method.
The instructions ”Check wire harness and connector” and
”Check and replace ECU” which appear in the inspection
procedure, are common and applicable to all diagnostic
trouble codes. Follow the procedure outlined below
whenever these instructions appear.
OPEN CIRCUIT:
This could be due to a disconnected wire harness, faulty con-
tact in the connector, a connector terminal pulled out, etc.
HINT:
It is rarely the case that a wire is broken in the middle of
it. Most cases occur at the connector. In particular, care-
fully check the connectors of sensors and actuators
Faulty contact could be due to rusting of the connector
terminals, to foreign materials entering terminals or a de-
formation of connector terminals. Simply disconnecting
and reconnecting the connectors once changes the
condition of the connection and may result in a return to
normal operation. Therefore, in troubleshooting, if no ab-
normality is found in the wire harness and connector
check, but the problem disappears after the check, then
the cause is considered to be in the wire harness or con-
nectors.
SHORT CIRCUIT:
This could be due to a contact between wire harness and the
body ground or to a short circuit occurred inside the switch, etc.
HINT:
When there is a short circuit between the wire harness and body
ground, check thoroughly whether the wire harness is caught
in the body or is clamped properly.
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
FI7187
IN0379
Sensor SideECU Side
IN0378
Sensor SideECU Side
IN0380
Sensor Side
ECU Side
IN0381
Pull Lightly
Looseness of Crimping
−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN−29
1996 LAND CRUISER (RM451U)
2. CONNECTOR HANDLING
When inserting tester probes into a connector, insert them from
the rear of the connector. When necessary, use mini test leads.
For water resistant connectors which cannot be accessed from
behind, take good care not to deform the connector terminals.
3. CONTINUITY CHECK (OPEN CIRCUIT CHECK)
(a) Disconnect the connectors at both ECU and sensor
sides.
(b) Measure the resistance between the applicable terminals of the connectors.
Resistance: 1 Ω or less
HINT:
Measure the resistance while lightly shaking the wire harness
vertically and horizontally.
4. RESISTANCE CHECK (SHORT CIRCUIT CHECK)
(a) Disconnect the connectors on both ends.
(b) Measure the resistance between the applicable terminals of the connectors and body ground. Be sure to carry out
this check on the connectors on both ends.
Resistance: 1 MΩ or higher
HINT:
Measure the resistance while lightly shaking the wire harness
vertically and horizontally.
5. VISUAL CHECK AND CONTACT PRESSURE CHECK
(a) Disconnect the connectors at both ends.
(b) Check for rust or foreign material, etc. in the terminals of the connectors.
(c) Check crimped portions for looseness or damage and check that the terminals are secured in lock portion.
HINT:
The terminals should not come out when pulled lightly from the
back.
c:::::J
o0
c::=J
o0
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
Z17004
Fig. 1
OPENECU
2
Sensor
22 2 1
111 AB
C
Z17005
Fig. 2
ECU
Sensor 21 A
B
C
1
1
22
B04722
Fig. 3
ECU
Sensor
21 A
C 1
1
221
2
1 B1
B2
IN−30−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 LAND CRUISER (RM451U)
(d) Prepare a test male terminal and insert it in the female ter-
minal, then pull it out.
NOTICE:
When testing a gold −plated female terminal, always use a
gold −plated male terminal.
HINT:
When the test terminal is pulled out more easily than others,
there may be poor contact in that section.
6. CHECK OPEN CIRCUIT
For the open circuit in the wire harness in Fig. 1, perform ”(a)
Continuity Check” or ”(b) Voltage Check” to locate the section.
(a) Check the continuity. (1) Disconnect connectors ”A” and ”C” and measurethe resistance between them.
In the case of Fig. 2:
Between terminal 1 of connector ”A” and terminal 1
of connector ”C” → No continuity (open)
Between terminal 2 of connector ”A” and terminal 2
of connector ”C” → Continuity
Therefore, it is found out that there is an open circuit
between terminal 1 of connector ”A” and terminal 1
of connector ”C”.
(2) Disconnect connector ”B” and measure the resis- tance between the connectors.
In the case of Fig. 3:
Between terminal 1 of connector ”A” and terminal 1
of connector ”B1” → Continuity
Between terminal 1 of connector ”B2” and terminal
1 of connector ”C” → No continuity (open)
Therefore, it is found out that there is an open circuit
between terminal 1 of connector ”B2” and terminal
1 of connector ”C”.
BE4063
DO
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
Z17007
Fig. 4Sensor 21 A
C
1
1
22B5V
5V
5V
0V
Z17008
Fig. 5
2
1 A
C
1
1
2 2
BSHORT
Z17009
Fig. 6
21 A
C
1
1
22
BSensor ECU
−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN−31
1996 LAND CRUISER (RM451U)
(b) Check the voltage.
In a circuit in which voltage is applied (to the ECU connec-
tor terminal), an open circuit can be checked for by con-
ducting a voltage check.As shown in Fig. 4, with each connector still con-
nected, measure the voltage between body ground
and terminal 1 of connector ”A” at the ECU 5V out-
put terminal, terminal 1 of connector ”B”, and termi-
nal 1 of connector ”C”, in that order.
If the results are:
5V: Between Terminal 1 of connector ”A” and Body Ground
5V: Between Terminal 1 of connector ”B” and Body Ground
0V: Between Terminal 1 of connector ”C” and Body Ground
Then it is found out that there is an open circuit in the wire har-
ness between terminal 1 of ”B” and terminal 1 of ”C”.
7. CHECK SHORT CIRCUIT
If the wire harness is ground shorted as in Fig. 5, locate the sec-
tion by conducting a ”continuity check with ground”.
Check the continuity with ground. (1) Disconnect connectors ”A” and ”C” and measurethe resistance between terminal 1 and 2 of connec-
tor ”A” and body ground.
In the case of Fig. 6:
Between terminal 1 of connector ”A” and body
ground → Continuity (short)
Between terminal 2 of connector ”A” and body
ground → No continuity
Therefore, it is found out that there is a short circuit
between terminal 1 of connector ”A” and terminal 1
of connector ”C”.
BE4066
BE4067
BE4068
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
Z17808
Fig. 7Sensor 21 A
B1
C
1
1
221 2
B2
ECU
IN0383
Example
Ground
IN0384
Ground
Ground
ECU Side
W/H Side
IN−32
−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 LAND CRUISER (RM451U)
(2) Disconnect connector ”B” and measure the resis-
tance between terminal 1 of connector ”A” and body
ground, and terminal 1 of connector ”B2” and body
ground.
In the case of Fig. 7:
Between terminal 1 of connector ”A” and body
ground → No continuity
Between terminal 1 of connector ”B2” and body
ground → Continuity (short)
Therefore, it is found out that there is a short circuit
between terminal 1 of connector ”B2” and terminal
1 of connector ”C”.
8. CHECK AND REPLACE ECU
First check the ECU ground circuit. If it is faulty, repair it. If it is
normal, the ECU could be faulty, so replace the ECU with a nor-
mal functioning one and check that the symptoms appear.
(1) Measure the resistance between the ECU groundterminal and the body ground.
Resistance: 1 Ω or less
(2) Disconnect the ECU connector, check the ground terminals on the ECU side and the wire harness
side for bend and check the contact pressure.
o
D~~~D~~~
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
IN04Q−07
−
INTRODUCTION TERMS
IN−33
33
Author: Date:
1996 LAND CRUISER (RM451U)
TERMS
ABBREVIATIONS USED IN THIS MANUAL
AbbreviationsMeaning
ABSAnti−Lock Brake System
ACAlternating Current
ACCAccessory
ACISAcoustic Control Induction System
ACSDAutomatic Cold Start Device
A.D.D.Automatic Disconnecting Differential
A/FAir−Fuel Ratio
AHCActive Height Control Suspension
ALRAutomatic Locking Retractor
ALTAlternator
AMPAmplifier
ANTAntenna
APPROX.Approximately
A/TAutomatic Transmission (Transaxle)
AT FAutomatic Transmission Fluid
AUTOAutomatic
AUXAuxiliary
AV GAverage
AV SAdaptive Variable Suspension
BABrake Assist
BACSBoost Altitude Compensation System
BATBattery
BDCBottom Dead Center
B/LBi−Level
B/SBore−Stroke Ratio
BTDCBefore Top Dead Center
BVSVBimetallic Vacuum Switching V alve
Calif.California
CBCircuit Breaker
CCoCatalytic Converter For Oxidation
CDCompact Disc
CFCornering Force
CGCenter Of Gravity
CHChannel
COMB.Combination
CPECoupe
CPSCombustion Pressure Sensor
CPUCentral Processing Unit
CRSChild Restraint System
CTRCenter
C/VCheck Valve
CVControl Valve
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010
IN−36
−
INTRODUCTION TERMS
36
Author: Date:
1996 LAND CRUISER (RM451U)
NA
Natural Aspiration
No.Number
O/DOverdrive
OEMOriginal Equipment Manufacturing
OHCOverhead Camshaft
OHVOverhead V
alve
OPTOption
O/SOversize
P & BVProportioning And Bypass Valve
PCSPower Control System
PCVPositive Crankcase Ventilation
PKBParking Brake
PPSProgressive Power Steering
PSPower Steering
PTOPower Take−Off
R & PRack And Pinion
R/BRelay Block
RBSRecirculating Ball Type Steering
R/FReinforcement
RFSRigid Front Suspension
RHRight−Hand
RHDRight−Hand Drive
RLYRelay
ROMRead Only Memory
RrRear
RRRear−Engine Rear −Wheel Drive
RRSRigid Rear Suspension
RWDRear− Wheel Drive
SDNSedan
SENSensor
SICSStarting Injection Control System
SMTSequential Manual T ransmission
SOCState Of Charge
SOHCSingle Overhead Camshaft
SPECSpecification
SPISingle Point Injection
SRSSupplemental Restraint System
SSMSpecial Service Materials
SSTSpecial Service Tools
STDStandard
STJCold−Start Fuel Injection
SWSwitch
SYSSystem
T/ATransaxle
TACHTachometer
TBIThrottle Body Electronic Fuel Injection
Brought to you by BirfMark
Brought to you by BirfMark
Version 1.11 - 03/16/2010