Toyota Camry owners & service manuals

Toyota Camry (XV70): Tire Pressure Monitor ECU Communication Stop (C2179)

Toyota Camry Repair Manual XV70 (2018-2024) / Suspension / Tire Pressure Monitoring / Tire Pressure Warning System / Tire Pressure Monitor ECU Communication Stop (C2179)

DESCRIPTION

The main body ECU (multiplex network body ECU) sends signals to the tire pressure warning ECU and receiver via a direct line.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Note

C2179

Tire Pressure Monitor ECU Communication Stop

Communication between the main body ECU (multiplex network body ECU) and tire pressure warning ECU and receiver is interrupted for 10 seconds or more.
  • Main body ECU (Multiplex network body ECU)
  • Wire harness or connector
  • Tire pressure warning ECU and receiver

-

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • When replacing the tire pressure warning ECU and receiver, read the transmitter IDs and number of the transmitters (4 or 5) stored in the old ECU using the Techstream and write them down before removal.
  • It is necessary to perform initialization after registration of the transmitter IDs into the tire pressure warning ECU and receiver after the ECU has been replaced.
  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.*

    Click here

  • *: w/ Smart Key System

PROCEDURE

1.

INSPECT MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (OUTPUT WAVEFORM)

(a) Using an oscilloscope, check the waveform.

NOTICE:

With the connector connected, check from the backside of the connector.

OK:

Tester Connection

Tool Setting Range

Condition

Specified Condition

K53-11 (PRG) - Body ground

5 V/DIV.5 ms./DIV.

Ignition switch ON

Waveform generation

*a

Component with harness connected

(Main Body ECU (Multiplex Network Body ECU))

*b

GND

Result

Proceed to

Waveform is as shown in the illustration. (Waveform alternates between 9.8 V or higher and 1.2 V or less)

A

Waveform does not change from 9.8 V or higher

B

Waveform does not change from 1.2 V or less

C
A

REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER

B

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

C

2.

CHECK TERMINAL VOLTAGE (TIRE PRESSURE WARNING ECU AND RECEIVER OUTPUT)

(a) Disconnect the K53 main body ECU (multiplex network body ECU) connector.

(b) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection

Condition

Specified Condition

K53-11 (PRG) - Body ground

Ignition switch ON

9.8 V or higher
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

3.

CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU AND RECEIVER - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))

(a) Turn the ignition switch off.

(b) Disconnect the R127 or R128 tire pressure warning ECU and receiver connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

w/ Smart Key System

Tester Connection

Condition

Specified Condition

R127-5 (PRG) - K53-11 (PRG)

Always

Below 1 Ω

R127-5 (PRG) or K53-11 (PRG) - Body ground

Always

10 kΩ or higher
w/o Smart Key System

Tester Connection

Condition

Specified Condition

R128-5 (PRG) - K53-11 (PRG)

Always

Below 1 Ω

R128-5 (PRG) or K53-11 (PRG) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

4.

CHECK HARNESS AND CONNECTOR (POWER SUPPLY - TIRE PRESSURE WARNING ECU AND RECEIVER)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

w/ Smart Key System

Tester Connection

Condition

Specified Condition

R127-7 (+B) - Body ground

Always

10 to 16 V

R127-1 (IG) - Body ground

Ignition switch ON

10 to 16 V
w/o Smart Key System

Tester Connection

Condition

Specified Condition

R128-7 (+B) - Body ground

Always

10 to 16 V

R128-1 (IG) - Body ground

Ignition switch ON

10 to 16 V
OK

REPLACE TIRE PRESSURE WARNING ECU AND RECEIVER

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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