Toyota Sequoia (2005). Manual - part 260

F19171

Tire Pressure
Monitor ECU

Tire Pressure Monitor 
Valve Sub–assy Front LH

Tire Pressure Monitor 
Valve Sub–assy Rear LH

Tire Pressure Monitor 
Valve Sub–assy Front RH

Tire Pressure Monitor 
Valve Sub–assy Rear RH

J29

A

H

J30

3

4

5

BD2

5

1

4

+5V

RDA

GND

L

V

BR–R

T19
Tire Pressure
Monitor Receiver

BD2

BD2

L

V

L

RF5V

RDA

GND2

Tire Pressure Monitor 
Valve Sub–assy Spare

J29

C

J29

B

I

J30

J

J30

BR–R

BR–R

J/C

T17

8

T17

7

T17

16

V

: Radio Signal

–

DIAGNOSTICS

TIRE PRESSURE WARNING SYSTEM

DI–835

1029

CIRCUIT DESCRIPTION

The tire pressure monitor valve sub–assy constantly sends radio waves to the tire pressure monitor receiver
assy. If the battery for the tire pressure monitor valve sub–assy is depleted, or if the tire pressure monitor
receiver assy is defective or comes off, the DTC will be output. DTCs C2121/21 to C2125/25 can only be
deleted by the tester. DTCs C2181/81 to C2185/85 can be deleted when the transmitter sends a force trans-
mission signal or the test mode ends. DTCs C2181/81 to C2185/85 are output only in the test mode.

DTC No.

DTC Detecting Condition

Trouble Area

C2121/21
C2122/22
C2123/23
C2124/24
C2125/25

A DTC is detected when the ECU receives no signals for
51 minutes or more, the vehicle speed is 5 mph (8 km/h) or
higher, and the ECU receives no signals for 12 minutes or
more.

Tire pressure monitor receiver assy

Each tire pressure monitor valve sub–assy

Tire pressure monitor ECU

Wire harness

C2181/81
C2182/82
C2183/83
C2184/84
C2185/85

Malfunction in the transmitting/receiving circuit

Tire pressure monitor receiver assy

Each tire pressure monitor valve sub–assy

Tire pressure monitor ECU

Wire harness

HINT:
It is necessary to perform the procedure to identify the tire pressure monitor valve sub–assy that is malfunc-
tioning because it cannot be identified by the output DTC.

WIRING DIAGRAM

DI–836

–

DIAGNOSTICS

TIRE PRESSURE WARNING SYSTEM

1030

INSPECTION PROCEDURE

NOTICE:
It is necessary to register an ID code after replacing the tire pressure monitor valve sub–assy and/or
the tire pressure monitor ECU (see page 

DI–805

).

HINT:
Set the tire pressure to the specified value.

1

Check tire pressure warning lamp.

PREPARATION:
Turn the ignition switch to the ON position.
CHECK:
Check the tire pressure warning lamp.
RESULT:

Does not blink

A

Comes on and goes off repeatedly at 0.5 second intervals

B

B

Go to step 4.

A

2

Clear DTC (See page 

DI–820

).

NEXT

3

Check DTC (See page 

DI–820

).

CHECK:
Check for a DTC.
OK:

DTC is not output.

NG

Go to step 4.

OK

Check problem symptoms table 
(See page 

DI–814

).

F19136

Tire Pressure Monitor ECU:

T17

RF5V

GND2

RDA

F19137

Tire Pressure Monitor Receiver Assy:

T19

+5V

GND

RDA

–

DIAGNOSTICS

TIRE PRESSURE WARNING SYSTEM

DI–837

1031

4

Check DTC (See page 

DI–820

).

CHECK:
Check if DTCs C2121/21, C2122/22, C2123/23, C2124/24 and C2125/25 are all output.

No

Go to step 10.

Yes

5

Check harness and connector (Tire pressure monitor receiver assy – Tire pres-
sure monitor ECU).

PREPARATION:
Disconnect the tire pressure monitor receiver assy T19 connec-
tor and tire pressure monitor ECU T17 connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Tester Connection

Specified Condition

T17–7 (RDA) – T19–1 (RDA)

Below 1 

Ω

T17–8 (RF5V) – T19–5 (+5V)

Below 1 

Ω

T17–16 (GND2) – T19–4 (GND)

Below 1 

Ω

T17–7 (RDA) – Body ground

10 k

Ω

 or higher

T17–8 (RF5V) – Body ground

10 k

Ω

 or higher

T17–16 (GND2) – Body ground

10 k

Ω

 or higher

NG

Repair or replace harness or connector.

OK

F19138

Tire Pressure Monitor ECU:

T17

RF5V

GND2

DI–838

–

DIAGNOSTICS

TIRE PRESSURE WARNING SYSTEM

1032

6

Inspect tire pressure monitor ECU.

PREPARATION:
(a)

Connect the tire pressure monitor ECU T17 connector.

(b)

Turn the ignition switch to the ON position.

CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:

Tester Connection

Condition

Specified Condition

T17–8 (RF5V) – 

T17–16 (GND2)

Ignition Switch ON

4.5 to 5.5 V

NG

Check power source circuit 
(See page 

DI–878

).

OK

7

Replace tire pressure monitor receiver assy (See page 

SA–13

).

HINT:
Perform the inspection using parts from a normal vehicle when possible.

NEXT

8

Check DTC 

(See page 

DI–820

).

PREPARATION:
Clear the DTCs.
CHECK:
Check for a DTC.
OK:

DTC is not output.

OK

End

NG