Page 489 of 4323
B17447
Wire Harness Side:
Stop Light Switch Connector
S14
ST1±STP
E4
± DIAGNOSTICSENGINE
DI±287
481 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check harness and connector between ECM and stop light switch.
PREPARATION:
(a) Disconnect the S14 stop light switch connector.
(b) Disconnect the E4 ECM connector.
CHECK:
Measure the resistance between the wire harness side connec-
tors.
OK:
Standard:
Tester ConnectionSpecified Condition
Stop light switch (S14±1) ± STP (E4±15)Below 1 W
Stop light switch (S14±3) ± ST1±
(E4±16)Below 1 W
Stop light switch (S14±1) or
STP (E4±15) ± Body ground10 kW or higher
Stop light switch (S14±3) or
ST1± (E4±16) ± Body ground10 kW or higher
NG Repair or replace harness or connector.
OK
Replace ECM (See page SF±80).
Page 490 of 4323

A20823
Idle engine
RPM
Small Target RPM
Actual idle RPMLarge
Learned value
of the idle speed
controlMaximum
Minimum
Time 0
Time DI±288
± DIAGNOSTICSENGINE
482 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0505 Idle Air Control System
CIRCUIT DESCRIPTION
The idle speed is controlled by the ETCS (Electronic Throttle Control System).
The ETCS is composed of the throttle motor which operates the throttle valve, and the throttle position sen-
sor, which detects the opening angle of the throttle valve.
The ECM controls the throttle motor to provide the proper throttle valve opening angle to obtain the target
idle speed.
DTC No.DTC Detection ConditionTrouble Area
P0501Idle speed continues to vary greatly from target speed
(2 trip detection logic)
ETCS
Air induction system
PCV hose connection
ECM
MONITOR DESCRIPTION
The ECM regulates the idle speed by opening and closing the throttle valve using the ETCS. The ECM con-
cludes that the idle speed control ECM function is malfunctioning if: 1) the actual idle RPM varies more than
the specified amount, or 2) a learning value of the idle speed control remains at the maximum or minimum
five times or more during a driving cycle. The ECM will turn on the MIL and set a DTC.
Example:
If the actual idle RPM varies from the target idle RPM by more than 100 (*1) rpm five times during a driving
cycle, the ECM will turn on the MIL and a DTC is set.
HINT:
*1: RPM threshold varies with engine load.
DICF6±02
Page 491 of 4323

± DIAGNOSTICSENGINE
DI±289
483 Author: Date:
2005 SEQUOIA (RM1146U)
MONITOR STRATEGY
Related DTCsP0505Idle air control malfunction
Main sensors/componentsCrankshaft position sensor
Required sensors/componentsRelated sensors/componentsVehicle speed sensor, Engine coolant tempera-
ture sensor
Frequency of operationOnce per driving cycle
Duration10 min.
MIL operation2 driving cycles
Sequence of operationNone
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
EngineRunning
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Either of the following conditions is met:Condition 1 or 2
1. Frequency that both of the following conditions (a) and (b)
are met:5 times or more
(a) Engine RPM ± target engine RPMLess than ±100 rpm or more than 150 rpm
(b) Vehicle conditionStop after vehicle was driven by 10 km/h (6.25 mph) or more
2. Frequency that both of the following conditions (a) and (b)
are met:Once
(a) Engine RPM ± target engine RPMLess than ±100 rpm or more than 150 rpm
(b) Intake air control flow rate learning value2.48 L/sec. or less, or 11 L/sec. or more
Page 492 of 4323

DI±290
± DIAGNOSTICSENGINE
484 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:
When the throttle position is slightly opened (the accelerator pedal is slightly depressed) because a
floor carpet is overlapped on the accelerator pedal, or if the accelerator pedal is not fully released, etc.,
DTC P0505 will possibly be detected.
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 Are there any other codes (besides P0505) being output?
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 / DTC
INFO / CURRENT CODES.
CHECK:
Read the DTC using the hand±held tester.
RESULT:
Display (DTC Output)Proceed to
P0505A
ºP0505º and other DTCsB
HINT:
If any other codes besides P0505 are output, perform the troubleshooting for those DTCs first.
B Go to relevant DTC chart (See page DI±58).
A
2 Check connection of PCV piping.
NG Repair or replace PCV piping.
OK
Page 493 of 4323
± DIAGNOSTICSENGINE
DI±291
485 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check air induction system (See page SF±1).
CHECK:
Check for vacuum leaks in air induction system.
OK:
No leakage.
NG Repair or replace air induction system.
OK
Check electric throttle control system
(See page SF±39).
Page 494 of 4323

DI±292
± DIAGNOSTICSENGINE
486 Author: Date:
2005 SEQUOIA (RM1146U)
DTC P0560 System Voltage
MONITOR DESCRIPTION
The battery supplies electricity to the ECM even when the ignition switch is OFF. This electricity allows the
ECM to store data such as DTC history, freeze frame data, fuel trim values, and other data.
If the battery voltage falls below a minimum level, the ECM will conclude that there is a fault in the power
supply circuit. The next time the engine starts, the ECM will turn on the MIL and a DTC will be set.
DTC No.DTC Detecting ConditionTrouble Area
P0560Open in back up power source circuit
Open in back±up power source circuit
EFI fuse
ECM
HINT:
If DTC P0560 present, the ECM will not store another DTC.
MONITOR STRATEGY
Related DTCsP0560System voltage malfunction
Required sensors/componentsECM
Frequency of operationContinuous
Duration3 sec.
MIL operationImmediate (*1)
Sequence of operationNone
*1: The DTC is set immediate. The MIL will be illuminated after the engine starts in the next time.
TYPICAL ENABLING CONDITIONS
ItSpecificationItemMinimumMaximum
The monitor will run whenever this DTC is
not presentSee page DI±18
Stand±by RAMInitialized
TYPICAL MALFUNCTION THRESHOLDS
Detection CriteriaThreshold
Battery voltageLess than 3.5 V
DICF7±02
Page 495 of 4323
A05652A18100
Battery2DEFI No. 1
B±Y
E4ECM
BATT 73
2H 1
IA411
B±Y B
F10
Fusible Link
Block 4Engine Room J/B
5
B12
± DIAGNOSTICSENGINE
DI±293
487 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
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 Check battery voltage.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to ON.
(c) Select the item: DIAGNOSIS / ENHANCED OBD II / DATA LIST / ALL / BATTERY VOLTAGE.
CHECK:
Read the battery voltage on the hand±held tester
RESULT:
Battery voltageProceed to
0 VA
Except 0 VB
B Go to step 5.
A
Page 496 of 4323
A21381
Engine Room J/B
EFI No. 1 Fuse
B17411
BATT (+) E6
E4
E1(±)
DI±294
± DIAGNOSTICSENGINE
488 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check EFI No. 1 fuse of engine room J/B.
PREPARATION:
Remove the EFI No. 1 fuse from the engine room J/B.
CHECK:
Check the resistance of the EFI No. 1 fuse.
OK:
Standard: Below 1 W
NG Check for short in all harness and components
connected to EFI No. 1 fuse.
OK
3 Check voltage between terminal BATT and E1 of ECM connector.
CHECK:
Measure the voltage between terminals of the E6 and E4 ECM
connector.
OK:
Standard:
Tester ConnectionSpecified Condition
BATT (E4±3) ± E1 (E6±1)9 to 14 V
OK Check for intermittent problems
(See page DI±11).
NG