Meter. Meter / Gauge System Speed Signal Circuit

The meter CPU receives vehicle speed signals from this circuit. The vehicle speed sensor detects the voltage that varies according to the vehicle speed. The skid control ECU supplies power to the vehicle speed sensor. The skid control ECU detects vehicle speed signals based on the pulses of the voltage. The skid control ECU transmits vehicle speed signals as pulses to the meter CPU. A voltage of 12 V is output from the combination meter assembly and then input to the skid control ECU. The signal is changed to a pulse signal at the transistor in the combination meter assembly.
A voltage of 12 V or 5 V is output from each ECU or relay and then input to the combination meter assembly.
Each ECU controls the respective system based on the pulse signal.

HINT:

This circuit is used for another system, and is not used for combination meter operation.

WIRING DIAGRAM

for 2AZ-FE

Camry. Acv40 Gsv40.Meter.Meter / Gauge System.Meter / Gauge System Speed Signal Circuit

for 2GR-FE

INSPECTION PROCEDURE

1.INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

Check the output waveform.
1. Remove the combination meter assembly with connector(s) still connected.
2. Connect the oscilloscope to the terminals F2-12 (+S) and body ground.
3. Turn the ignition switch to the ON position.
4. Turn the wheel slowly.
5. Check the signal waveform according to the condition(s) in the table below.
  Item
  Condition
  Tool setting
  5 V/DIV., 20 ms./DIV.
  Vehicle condition
  Driving at approx. 20 km/h (12 mph)
  OK:
  The waveform is displayed as shown in the illustration.
  HINT:
  When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.

Go to step 2

RETURN TO THE ORIGINAL INSPECTION FOR OTHER SYSTEM

2.INSPECT ECU TERMINAL VOLTAGE (INPUT VOLTAGE)

Remove the F2 connector.

Measure the voltage according to the value(s) in the table below.
Standard voltage:
Tester Connection
Condition
Specified Condition
F2-12 (+S) - Body ground
Turn the ignition switch to the ON position
4.5 to 14 V
HINT:
If any of the ECUs specified in the wiring diagram supplied power to the combination meter, the combination meter will output a waveform.

Go to step 5

OK

3.INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)

Remove the A25 (*1)/A26 (*2) connector.

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

Standard voltage:

Tester Connection	Condition	Specified Condition
A25-23 (SP1) (*1) - Body ground	Turn the ignition switch to the ON position	10 to 14 V
A26-12 (SP1) (*2) - Body ground	Turn the ignition switch to the ON position	10 to 14 V

*1: without VSC
*2: with VSC

Go to step 13

OK

4.INSPECT SKID CONTROL ECU (INPUT WAVEFORM)

Check the input waveform.
1. Reconnect the A25 (*1)/A26 (*2) connector.
2. Remove the combination meter assembly with connector(s) still connected.
3. Connect the oscilloscope to the terminals F2-14 (SI) and body ground.
4. Turn the ignition switch to the ON position.
5. Turn the wheel slowly.
6. Check the signal waveform according to the condition(s) in the table below.
  Item
  Condition
  Tool setting
  5 V/DIV., 20 ms./DIV.
  Vehicle condition
  Driving at approx. 20 km/h (12 mph)
  OK:
  The waveform is displayed as shown in the illustration.
  HINT:
  1. When the system is functioning normally, one wheel revolution generates 4 pulses. As the vehicle speed increases, the width indicated by (A) in the illustration narrows.
  2. *1: without VSC
  3. *2: with VSC

REPLACE SKID CONTROL ECU

REPLACE COMBINATION METER ASSEMBLY

5.CHECK HARNESS AND CONNECTOR (COMBINATION METER - NO. 3 JUNCTION BLOCK)

Disconnect the 3P to 3U No. 3 junction block connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
F2-12 (+S) - 3P-3
Always
Below 1 Ω
F2-12 (+S) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

6.CHECK HARNESS AND CONNECTOR (NO. 3 JUNCTION BLOCK)

Inspect for a short in the circuit that connected the No. 3 junction block shown in the wiring diagram.
HINT:
If voltage is not present, the circuit (ECU) was possibly the malfunctioning circuit, This is the circuit that will be diagnosed by following the A step that follows.
1. Disconnect the 3H to 3O and 3A to 3H No. 3 junction block connectors.
2. Measure the voltage according to the value(s) in the table below.
  Standard voltage:
  Tester Connection
  Condition
  Specified Condition
  3B-10 - Body ground
  Turn the ignition switch to the ON position
  4.5 to 14 V
  3J-9 - Body ground
  Turn the ignition switch to the ON position
  4.5 to 14 V
3. Reconnect the 3H to 3O No. 3 junction block connectors.
4. Measure the voltage according to the value(s) in the table below.
  Standard voltage:
  Tester Connection
  Condition
  Specified Condition
  3T-9 - Body ground
  Turn the ignition switch to the ON position
  4.5 to 14 V
  
  Result:
  
  Result
  Proceed to
  Voltage is not present in one circuit
  A
  Voltage is present in all the circuit.
  B

REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 3 JUNCTION BLOCK)

A

7.SYSTEM CHECK

Select the circuit in which is not present voltage in step 6.

Result:

Tester Connection	System that uses the circuit	Proceed to
3T-9 - Body ground	Audio/visual System	A
3J-9 - Body ground	Wiper and Washer System	B
3B-10 - Body ground	SFI System	C
3B-10 - Body ground	Lighting System	D
3B-10 - Body ground	Automatic Transaxle System	E

A

8.CHECK HARNESS AND CONNECTOR (RADIO RECEIVER CIRCUIT)

Disconnect the F8 connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
F8-5 (SPD) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE RADIO RECEIVER ASSEMBLY

9.CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER REPLAY CIRCUIT)

Disconnect the E26 connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
E26-19 (SPD) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE WINDSHIELD WIPER RELAY

10.CHECK HARNESS AND CONNECTOR (ECM CIRCUIT)

Disconnect the A24 (*1) or A55 (*2) connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
A24-8 (SPD) (*1) - Body ground
Always
10 kΩ or higher
A55-8 (SPD) (*2) - Body ground
Always
10 kΩ or higher
*1: for 2AZ-FE, or LHD for 2GR-FE
*2: RHD for 2GR-FE

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE ECM

11.CHECK HARNESS AND CONNECTOR (HEADLIGHT LEVELING ECU CIRCUIT)

Disconnect the A20 connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
A20-16 (SPDR) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE HEADLIGHT LEVELING ECU

12.CHECK HARNESS AND CONNECTOR (TCM CIRCUIT)

Disconnect the C56 connector.

Measure the resistance according to the value(s) in the table below.
Standard resistance:
Tester Connection
Condition
Specified Condition
C56-3 (SPD1) - Body ground
Always
10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE TCM

13.CHECK HARNESS AND CONNECTOR (COMBINATION METER - SKID CONTROL ECU)

Disconnect the F2 connector.

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

Standard resistance:

Tester Connection	Condition	Specified Condition
A25-23 (SP1) (*1) - F2-14 (SI)	Always	Below 1 Ω
A25-23 (SP1) (*1) - Body ground	Always	10 kΩ or higher
A26-12 (SP1) (*2) - F2-14 (SI)	Always	Below 1 Ω
A26-12 (SP1) (*2) - Body ground	Always	10 kΩ or higher

*1: without VSC
*2: with VSC

REPAIR OR REPLACE HARNESS OR CONNECTOR

REPLACE COMBINATION METER ASSEMBLY

Item	Condition
Tool setting	5 V/DIV., 20 ms./DIV.
Vehicle condition	Driving at approx. 20 km/h (12 mph)

Result	Proceed to
Voltage is not present in one circuit	A
Voltage is present in all the circuit.	B