Page 497 of 4323
A21381
Engine Room J/B
EFI No. 1 Fuse
B17417
E4
BATT ECM Connector
± DIAGNOSTICSENGINE
DI±295
489 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check for open and short in harness and connector between ECM and EFI No. 1
fuse, EFI No. 1 fuse and battery.
PREPARATION:
(a) Remove the EFI No. 1 fuse from the engine room J/B.
(b) Disconnect the E4 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tor.
OK:
Standard:
Tester ConnectionSpecified Condition
Engine Room J/B (EFI No. 1 fuse
terminal 2) ± BATT (E4±3)Below 1 W
Engine Room J/B (EFI No. 1 fuse
terminal 2) or BATT (E4±3) ±
Body ground
10 kW or higher
NG Repair or replace harness or connector.
OK
5 Check the battery (See page CH±1).
NG Replace battery.
OK
Check and replace engine room J/B.
Page 498 of 4323

DI±296
± DIAGNOSTICSENGINE
490 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0604 Internal Control Module Random Access
Memory (RAM) Error
DTC P0606 ECM/PCM Processor
DTC P0607 Control Module Performance
DTC P0657 Actuator Supply Voltage Circuit / Open
MONITOR DESCRIPTION
The ECM continuously monitors its internal memory status, internal circuits, and output signals to the throttle
actuator. This self±check insures that the ECM is functioning properly. If any malfunction is detected, the
ECM will set the appropriate DTC and illuminate the MIL.
The ECM memory status is diagnosed by internal ºmirroringº of the main CPU and the sub CPU to detect
RAM (Random Access Memory) errors. The two CPUs also perform continuous mutual monitoring.
The ECM sets a DTC if: 1) outputs from the 2 CPUs are different and deviate from the standards, 2) the sig-
nals to the throttle actuator deviate from the standards, 3) a malfunction is found in the throttle actuator sup-
ply voltage, and 4) any other ECM malfunction is found.
DTC No.DTC Detecting ConditionTrouble Area
P0604
P0606
P0607
P0657
ECM malfunctionECM
MONITOR STRATEGY
P0604Random access memory (RAM) error
RltdDTCP0606CPU malfunctionRelated DTCsP0607ECM range check
P0657ETCS power supply
Required sensors/componentsECM
Frequency of operationContinuous
DurationWithin 1 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
The monitor will run whenever these
DTCs are not presentSee page DI±18
The typical enabling condition is not avail-
able±
DI3IK±13
Page 499 of 4323

± DIAGNOSTICSENGINE
DI±297
491 Author: Date:
2005 SEQUOIA (RM1146U)
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
P0604:
RAMRAM check failure
P0606:
Either of the following conditions is metCondition 1 or 2
1. Difference between TP of main CPU and TP of sub CPU0.3 V or more
2. Difference between APP of main CPU and APP of sub
CPU0.3 V or more
P0607:
Either of the following conditions is metCondition 1 or 2
1. All of the following conditions are metCondition (a), (b) and (c)
(a) CPU reset1 time or more
(b) Difference between TP and APP learned0.4 V or more
(c) Electronic throttle actuatorOFF
2. CPU reset2 times or more
P0657:
ECTS power supply when ignition switch OFF to ON7 V or more
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand-held tester. Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was
running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, as well as other
data from the time when a malfunction occurred.
Replace ECM (See page SF±80).
Page 500 of 4323

DI±298
± DIAGNOSTICSENGINE
492 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0617 Starter Relay Circuit High
MONITOR DESCRIPTION
While the engine is being cranked, the battery positive voltage is applied to terminal STA of the ECM.
If the vehicle is being driven and the ECM detects the starter control signal (STA), the ECM concludes that
the starter control circuit is malfunctioning. The ECM will turn on the MIL and a DTC is set.
DTC No.DTC Detection ConditionTrouble Area
P0617
When all conditions (a), (b) and (c) are satisfied for 20 seconds
with battery (+B) voltage 10.5 V or more
(a) Vehicle speed 20 km/h (12.4 mph)
(b) Engine revolution 1,000 rpm
(c) STA signal ONPark/neutral position switch
Starter relay circuit
Ignition switch
ECM
MONITOR STRATEGY
Related DTCsP0617Starter signal error
Rid / tMain sensors/componentsStarter signalRequired sensors/componentsRelated sensors/componentsVehicle speed sensor, Engine speed sensor
Frequency of operationContinuous
Duration20 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Battery voltage10.5 V±
Vehicle speed20 km/h (12.4 mph)±
Engine RPM1,000 rpm±
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Starter signalON (at ºmore than 20 km/h (12.4 mph) and more than 1,000 rpmº)
DID8D±01
Page 501 of 4323
A23548
ECM
E4
STAR ACCR
AM28
ED I18
Ignition SWB B
B±W 1C9
620
42 P
1
B±W
B 1
J2
J/C 1
17
B±O
2D
ALTE7 J38
1FGR
W4
ED2 IA1
S3 F10
Fusible
Link Block4
W±R
B±L
Battery 5B
ST 3A
1
StarterST Relay 5
B
12 3
Instrument Panel J/B
12
Engine Room J/B
2C
5 Sub J/B No. 4
P 3A 12A36
ACC CUT Relay
to Audio
J37J/C
C
GR
4 GR
N B±R
B±R
J/C BD
J51 J52B±R
STSW
E6 IG4B
Engine Room R/B No.2
2 B
2 2
2
2 2 B±RB±R RAD No.2
1C
1C
1C
1J 1J1J
1L
1E 3
5
W±L W±R
W±R
2C
2E1
3B±R
3
B1
B±W
W±B 6
A 1
2 3 58
3
J5
J/C 1
1W±B 128 B±R
W±RJ51 BE6 11
STA W±R
21
3
S2W±R4A
4B 19
9 Sub J/B No.4 GR
P1
Park/Neutral
Position SW
AM1ACC
AM2
ST2
ECU±B
SHORT PIN
B 7
B 2AM1
1
STA8
IA5
± DIAGNOSTICSENGINE
DI±299
493 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 502 of 4323

DI±300
± DIAGNOSTICSENGINE
494 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand±held tester. Freeze frame data records the engine conditions when
a malfunction is detected. When troubleshooting, freeze frame data can help determine if the vehicle was
running or stopped, if the engine was warmed up or not, if the air±fuel ratio was lean or rich, as well as other
data from the time when a malfunction occurred.
1 Connect hand±held tester, and check STA signal.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON, and push the hand±held tester main switch ON.
(c) When using hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA
LIST / ALL / STARTER SIG.
CHECK:
Read the STA signal on the hand±held tester while the starter operates.
OK:
Standard:
Ignition Switch PositionONSTART
STARTER SIGOFFON
OK Go to step 5.
NG
2 Check park/neutral position switch (See page DI±576).
NG Replace park/neutral position switch.
Go to next step 5 after the replacement.
OK
3 Check ignition switch (See page BE±24).
NG Replace ignition switch.
Go the next step 5 after the replacement.
OK
Page 503 of 4323
± DIAGNOSTICSENGINE
DI±301
495 Author: Date:
2005 SEQUOIA (RM1146U)
4 Connect hand±held tester, and check STA signal.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON, and push the hand±held tester main switch ON.
(c) On the hand±held tester, enter the following menu: DIAGNOSIS / ENHANCED OBD II / DATA LIST
/ ALL / STARTER SIG.
CHECK:
Read the STA signal on the hand±held tester while the starter operates.
OK:
Standard:
Ignition Switch PositionONSTART
STARTER SIGOFFON
NG Repair or replace harness or connector.
OK
5 Check DTC reoccur
PREPARATION:
(a) Connect the hand±held tester.
(b) Turn the ignition switch ON and hand±held tester main switch ON.
(c) Clear DTC (See page DI±43).
(d) Drive the vehicle more than 40 km/h (25 mph) for 20 seconds or more.
CHECK:
Check DTC reoccur.
RESULT:
Display (DTC Output)Proceed to
P0617A
No DTC outputB
A Replace ECM (See page SF±80).
B
Check for intermittent problems
(See page DI±11).
Page 504 of 4323

DI±302
± DIAGNOSTICSENGINE
496 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0630 VIN not Programmed or Mismatch ECM/PCM
CIRCUIT DESCRIPTION
DTC P0630 is set when the Vehicle Identification Number (VIN) is not stored in the Engine Control Module
(ECM) or the input VIN is not accurate. Input the VIN with the hand±held tester.
DTC No.DTC Detecting ConditionTrouble Area
P0630VIN is not stored in ECM.
Input VIN in ECM is not accurate.ECM
MONITOR STRATEGY
Related DTCsP0630VIN not programmed
Rid / tMain sensors/componentsECMRequired sensors/componentsRelated sensors/components±
Frequency of operationContinuous
Duration0.5 sec.
MIL operationImmediate
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Battery voltage8 V±
Ignition switchON
StarterOFF
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
VIN codeNot programmed
COMPONENT OPERATING RANGE
ParameterStandard Value
VIN codeProgrammed
DID8E±01