Toyota Sequoia (2005). Manual — part 636

I28835

24

Y–B

W–R

A3
A/C Magnetic Clutch
and Lock Sensor

2

1

IG4

SG–TAM

Integration Control
and Panel

13

I19 LOCK

20

I19

Y–B

W–R

J14
J/C

A

A

23

Y–B

IG4

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

DI–2339

2533

DTC

22

Compressor Lock Sensor Circuit

CIRCUIT DESCRIPTION

This sensor sends 1 pulse per engine revolution to the integration control and panel.
If the compressor speed divided by the engine speed is smaller than a predetermined value, the integration
control and panel turns the compressor OFF. The indicator flashes at about 1 second intervals.

DTC No.

Detection Item

Trouble Area

22

All conditions below are detected for 3 sec. or more

(a) Engine speed: 450 rpm or more

(b) Ratio of engine to compressor speed deviates 20% or more

in comparison to normal operation.

Compressor drive belt

Compressor lock sensor

Compressor

Harness or connector between compressor lock sensor and

integration control and panel

Integration control and panel

WIRING DIAGRAM

DIDKY–01

I05252

2

1

N02774

0.2 V/Din.

LOCK IN signal waveform

0 V

20 msec/Division (Idling)

DI–2340

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

2534

INSPECTION PROCEDURE

1

Check compressor.

PREPARATION:
(a)

Check and adjust compressor drive belt tension (See page

AC–15

).

CHECK:
(a)

Check that the compressor does not lock when starting the engine and turning the A/C switch on.
OK: Cooler compressor assy does not lock during operation

HINT:
If the compressor drive belt slips when the A/C switch is on, the magnet clutch seems to be locked.
If the condition continues for more than 3 seconds, the A/C amplifier turns off the magnet clutch for compres-
sor drive belt protection.

NG

Replace compressor.

OK

2

Check compressor lock sensor.

PREPARATION:
Disconnect the compressor connector.
CHECK:
Measure the resistance between terminals 1 and 2 of the com-
pressor lock sensor connector.
OK:

Resistance : 65 to 125

Ω

at 20

°

C (68

°

F)

Reference: Inspection using oscilloscope
During cranking or idling, measure the voltage between termi-
nals LOCK and SG–TAM of the integration control and panel.
HINT:
The correct waveform appears as shown in the illustration on
the left.

NG

Replace compressor.

OK

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

DI–2341

2535

3

Check harness and connector between compressor lock sensor and integration
control and panel (See page

IN–24

).

NG

Repair or replace harness or connector.

OK

Replace integration control and panel.

I29011

ON (Below 1.0

Ω

)

Low pressure side

High pressure side

OFF
(10 k

Ω

or higher)

OFF
(10 k

Ω

or higher)

(2.0 kgf

⋅

cm

2

, 28 psi) (32.0 kgf

⋅

cm

2

, 455 psi)

196 KPa

3,140 KPa

DI–2342

–

DIAGNOSTICS

AIR CONDITIONING SYSTEM

2536

DTC

23

Pressure Switch Circuit

CIRCUIT DESCRIPTION

The pressure switch sends the appropriate signals to the A/C
amplifier when the A/C refrigerant pressure drops too low or
rises too high. When the A/C amplifier receives these signals,
it outputs signals through the A/C amplifier to turn the magnet
clutch relay off and turns the magnetic clutch off.

DTC No.

Detection Item

Trouble Area

23

Open in pressure sensor circuit.

Abnormal refrigerant pressure.

below 196 kPa (2.0 kg/cm

2

, 28 psi)

over 3,140 kPa (32.0 kgf/cm

2

, 455 psi)

Pressure switch

Harness or connector between pressure switch and integra-

tion control and panel

Refrigerant pipe line

Integration control and panel

DI3FD–09