Toyota Sequoia (2005). Manual - part 123

B17447

Wire Harness Side:

Stop Light Switch Connector

S14

ST1–

STP

E4

–

DIAGNOSTICS

ENGINE

DI–287

481

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 Connection

Specified Condition

Stop light switch (S14–1) – STP (E4–15)

Below 1 

Ω

Stop light switch (S14–3) – ST1–

(E4–16)

Below 1 

Ω

Stop light switch (S14–1) or 

STP (E4–15) – Body ground

10 k

Ω 

or higher

Stop light switch (S14–3) or 

ST1– (E4–16) – Body ground

10 k

Ω 

or higher

NG

Repair or replace harness or connector.

OK

Replace ECM (See page 

SF–80

).

A20823

Idle engine
RPM

Small

Target RPM

Actual idle RPM

Large

Learned value 
of the idle speed 
control

Maximum

Minimum

Time

0

Time

DI–288

–

DIAGNOSTICS

ENGINE

482

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 Condition

Trouble Area

P0501

Idle 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

–

DIAGNOSTICS

ENGINE

DI–289

483

MONITOR STRATEGY

Related DTCs

P0505

Idle air control malfunction

Main sensors/components

Crankshaft position sensor

Required sensors/components

Related sensors/components

Vehicle speed sensor, Engine coolant tempera-
ture sensor

Frequency of operation

Once per driving cycle

Duration

10 min.

MIL operation

2 driving cycles

Sequence of operation

None

TYPICAL ENABLING CONDITIONS

It

Specification

Item

Minimum

Maximum

The monitor will run whenever this DTC is
not present

See page 

DI–18

Engine

Running

TYPICAL MALFUNCTION THRESHOLDS

Detection Criteria

Threshold

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 RPM

Less than –100 rpm or more than 150 rpm

(b) Vehicle condition

Stop 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 RPM

Less than –100 rpm or more than 150 rpm

(b) Intake air control flow rate learning value

2.48 L/sec. or less, or 11 L/sec. or more

DI–290

–

DIAGNOSTICS

ENGINE

484

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

P0505

A

”P0505” and other DTCs

B

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