Page 1777 of 4323
DID50±01
C00083DLC3
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
DI±1575
1769 Author: Date:
2005 SEQUOIA (RM1146U)
DIAGNOSIS SYSTEM
1. DIAGNOSIS SYSTEM
(a) Inspect the battery voltage.
Battery voltage: 11 to 14 V
If voltage is below 11 V, recharge the battery before proceeding.
(b) Check the DLC3.
The transponder key ECU uses ISO 9141±2 for commu-
nication. The terminal arrangement of the DLC3 complies
with SAE J1962 and matches the ISO 9141±2 format.
Page 1778 of 4323

DID51±01
A04550
CG
OP3
DLC3 12345678
9
1011
13 1516 12 14
TC
I28427
Security Indicator
Light MIL
BR3904
Normal System Code
0.25 Sec.0.25 Sec.
I02680
Diagnostic Trouble Code (Example Code 12, 99)
0.5 Sec. 0.5 Sec.
1.5 Sec. 2.5 Sec.
One Cycle4.5 Sec.Repeat
DI±1576
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1770 Author: Date:
2005 SEQUOIA (RM1146U)
DTC CHECK / CLEAR
1. INSPECT DIAGNOSIS
(a) Check the DTC using SST check wire.
(1) Turn the ignition switch ON, but do not start the en-
gine.
(2) When checking DTC 99: Using SST, connect termi-
nals 13 (TC) and 4 (CG) of the DLC3.
(3) When checking codes except DTC 99: Using SST,
connect terminals 8 (OP3) and 4 (CG) of the DLC3.
SST 09843±18040
(4) Read the DTC indicated by the number of times the
security indicator light or the MIL blinks.
HINT:
If no DTC is output, inspect the diagnosis circuits (OP3
and TC) and the security indicator light circuit (See page
DI±1597, DI±1567, DI±1599).
If the system is operating normally, the light blinks twice
per second.
As an example, the blinking patterns of the normal system
code and trouble codes 12 and 99 are shown on the left
and below.
Page 1779 of 4323
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
DI±1577
1771 Author: Date:
2005 SEQUOIA (RM1146U)
(5) When DTC º99º is output, there is a problem with the
immobiliser. Start troubleshooting referring to the
PROBLEM SYMPTOMS TABLE.
(6) After completing the check, disconnect terminals 8
(OP3) and 4 (CG), or terminals 13 (TC) and 4 (CG),
and turn off the display.
HINT:
If 2 or more trouble codes exist, indication will begin from the
lowest numbered code.
(b) Clear the DTC.
(1) When using diagnosis check wire:
Remove the ECU±B fuse and EFI No. 2 fuse from
the engine room J/B for 1 minute or more.
Page 1780 of 4323

DI1AM±35
DI±1578
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1772 Author: Date:
2005 SEQUOIA (RM1146U)
DIAGNOSTIC TROUBLE CODE CHART
ECM DIAGNOSTIC TROUBLE CODE CHART (MIL)
DTC No.
(See page)Detection ItemTrouble Area
99
(DI±1580)Engine immobiliser system malfunction
Transponder key ECU
ECM
Wire harness
TRANSPONDER KEY ECU DIAGNOSTIC TROUBLE CODE CHART (SECURITY INDICATOR LIGHT)
DTC No.
(See page)Detection ItemTrouble Area
11
(DI±1582)Code 11 is not output
Unlock warning switch
Transponder key ECU
Wire harness
12
(DI±1585)Code 12 is not output
Driver door courtesy lamp switch
Transponder key ECU
Body ECU
Wire harness
13
(DI±1587)Code 13 is not output
Ignition switch
Transponder key ECU
Wire harness
21, 22
(DI±1589)Code 21 or 22 is not output
Key
Transponder key ECU
Transponder key amplifier with key coil
Wire harness
31, 35, 36, 37
(DI±1592)Code 31, 35, 36 or 37 is outputKey
32, 33
(DI±1593)Code 32 or 33 is output
Key
Transponder key ECU
Wire harness
34Code 34 is outputTransponder key ECU has no memory space to register anoth-
er key code
HINT:
DTCs 11, 12, 13, 21 and 22 are normal codes.
As for the normal codes, if the corresponding DTC is not output while operating any of the components
listed under ºTrouble Areaº, perform the inspection described in the reference pages.
DTCs 31, 32, 33, 34, 35, 36, 37 and 99 are abnormal codes.
Page 1781 of 4323
DI3DP±10
I28395
ECM Transponder Key Coil
Transponder Key Amplifier Instrument
Panel J/B
IGN Fuse
Engine Room J/B
ECU±B Fuse
EFI No. 1 Fuse
Transponder Key ECU
Combination Meter
Security Indicator Light
MIL
DLC3
(Located behind the combination meter)
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
DI±1579
1773 Author: Date:
2005 SEQUOIA (RM1146U)
PARTS LOCATION
Page 1782 of 4323
DIABC±03
I24830
ECMT16
Transponder Key ECU
IMI
IMO16
15P ± G
11
10EFIO
EFII L ± Y E5
E5 DI±1580
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1774 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT INSPECTION
DTC 99 Engine Immobiliser System Malfunction
CIRCUIT DESCRIPTION
This DTC is indicated when a DTC is output from the transponder key ECU, or when there is an open or short
circuit in the wire harness between the transponder key ECU and the ECM.
If the DTC is output after replacing the transponder key ECU or ECM, carry out the ECU communication ID
registration.
DTC No.DTC Detecting ConditionTrouble Area
99
Error in communication between ECM and transponder key
ECU, or in communication line.
Communication ID is different in communication with trans-
ponder key ECU.
ECU communication ID has not been registered
Transponder key ECU
ECM
Wire harness
WIRING DIAGRAM
Page 1783 of 4323
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
DI±1581
1775 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Has ECU communication ID registration been carried out? (See page BE±137)
NO Carry out ECU communication ID registration
again.
YES
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).
Page 1784 of 4323
I24832
Transponder Key ECU Body ECU
KSW Y±G
T169
KSW2
B515 DI±1582
± DIAGNOSTICSENGINE IMMOBILISER SYSTEM
1776 Author: Date:
2005 SEQUOIA (RM1146U)
Code 11 is not output
CIRCUIT DESCRIPTION
The transponder key ECU outputs DTC 11 when the key unlock warning switch is ON (key is inserted).
HINT:
DTC 11 is a normal code.
DTC No.DTC Detecting ConditionTrouble Area
11Key unlock warning switch operates normally.
Unlock warning switch
Transponder key ECU
Wire harness
WIRING DIAGRAM
DIABD±03