2001 TOYOTA SEQUOIA Page 18

± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
DI±1591
1785 Author: Date:
2005 SEQUOIA (RM1146U)
4 Does the system operate normally after replacement of transponder key ECU?
YES Replace transponder key ECU.
NO
Replace ECM (See page IN±35).

DI±1592
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1786 Author: Date:
2005 SEQUOIA (RM1146U)
Code 31, 35, 36 or 37 is output.
CIRCUIT DESCRIPTION
These DTCs are indicated when an unregistered key is inserted. When any of them is indicated, clear the
DTC and insert other registed keys to check for DTCs.
When a key that outputs a DTC (31, 35, 36 or 37) is found, register this key. When a DTC (31, 35, 36 or 37)
is not output, there is a possibility that the unregistered key has been inserted before. (The ECM is normal.)
Ask the customer under what conditions the problem occurred to find the cause.
(Example: Another key has been inserted, etc.)
DTC No.DTC Detecting ConditionTrouble Area
31, 35, 36, 37Unmatched key codeKey
INSPECTION PROCEDURE
1 Delete DTC and insert all the presently available keys to check whether the en-
gine starts or not (See page DI±1576).
HINT:
When inserting a key that does not start the engine, a DTC (31, 35, 36 or 37) is stored in memory.
RESULT:
OKAll keys start the engine.
NGA specific key does not start the engine.
OK No problem.
HINT:
If the result is ºOKº, confirm whether or not the customer ever
inserted an unregistered key or the immobiliser key (with a
transponder chip) of another vehicle into the ignition key cylin-
der, and find out the cause of the detection of the DTC.
NG
Register the key that does not start the en-
gine
(See page BE±137).
DIABH±04

DI±1594
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1788 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check whether the engine can be started with a spare key of the same vehicle.
YES Replace key.
NO
2 Check harness and connector between transponder key ECU and ECM (See
page IN±35).
NG Repair or replace harness or connector.
OK
3 Does the system operate normally after replacement of transponder key ECU?
YES Replace transponder key ECU.
NO
Replace ECM (See page IN±35).

DI±1596
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1790 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check ECU±B fuse.
CHECK:
Check for continuity of the ECU±B fuse.
OK:
Continuity
NG Replace fuse.
OK
2 Check voltage between terminals +B and GND of transponder key ECU connec-
tor.
PREPARATION:
(a) Turn the ignition switch OFF.
(b) Disconnect the transponder key ECU connector.
CHECK:
Measure the voltage between terminals +B and GND.
OK:
Voltage: 10 to 14 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI±1573).
NG
3 Check wire harness and connector between terminal GND of transponder key
ECU and body ground (See page IN±35).
NG Repair or replace wire harness or connector.
OK
Check and repair wire harness and connec-
tor between transponder key ECU and bat-
tery.

I24836
ON
IND
(±) (+)
DI±1598
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1792 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check voltage between terminal IND of transponder key ECU connector and
body ground.
PREPARATION:
Turn the ignition switch to the ON position and enter diagnosis
mode.
CHECK:
Measure the voltage between terminal IND of the transponder
key ECU connector and body ground when the security indica-
tor light is on and when it is off.
OK:
Indicator lightVoltage
ON3 to 6 V
OFFBelow 1 V
NG Proceed to next circuit inspection shown in
problem symptoms table (See page DI±1573).
OK
2 Check combination meter (See page DI±1610).
NG Replace combination meter.
OK
Check and replace wire harness and connec-
tor (See page IN±35).

A04550
CGOP3
1 234 5 678
91011 13 151612 14
DI±1600
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1794 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check voltage between terminals OP3 and CG of DLC3.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals OP3 and CG of the
DLC3.
OK:
Voltage: 10 to 14 V
OK Proceed to next circuit inspection shown in
problem symptoms table (See page DI±1573).
NG
2 Check harness and connector between transponder key ECU and DLC3, DLC3
and body ground (See page IN±35).
NG Repair or replace harness or connector.
OK
Replace transponder key ECU
(See page IN±35).

DID8N±01
± DIAGNOSTICSCOMBINATION METER SYSTEM
DI±1601
1795 Author: Date:
2005 SEQUOIA (RM1146U)
COMBINATION METER SYSTEM
PRECAUTION
NOTICE:
When disconnecting the battery terminal, initialize the following system after the terminal is recon-
nected.
System NameSee Page
Back Door Power Window Control SystemBE±77

DID8R±01
DI±1610
± DIAGNOSTICSCOMBINATION METER SYSTEM
1804 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
1 Vehicle Brought To Workshop
NEXT
2 Customer Problem Analysis (See page DI±1612)
NEXT
3 Check Multiplex Communication System (See page DI±1904)
Check if any DTCs are output.
HINT:
The combination meter of this system is connected to the multiplex communication system. Therefore, be-
fore starting troubleshooting, make sure to check that there is no trouble in the multiplex communication sys-
tem.
Multiplex Communication System DTC Is Out-
put (Proceed To ºMULTIPLEX COMMUNICA-
TION SYSTEMº (See page DI±1892))
No Multiplex Communication System DTC (Go
to step 4)
4 Problem Symptom Confirmation
Symptom Does Not Occur (Go to step 5)
Symptom Occurs (Go to step 6)
5 Symptom Simulation (See page DI±1892)
NEXT