Speed Signal Circuit

METER: METER / GAUGE SYSTEM: Speed Signal Circuit
- Speed Signal Circuit

DESCRIPTION

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

1. for 2AR-FE





2. for 2GR-FE





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT COMBINATION METER ASSEMBLY (OUTPUT WAVEFORM)

(a) 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) Ignition switch on (IG).

(4) Turn the wheel slowly.

(5) Check the signal waveform according to the condition(s) in the table below.





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.

NG -- INSPECT ECU TERMINAL VOLTAGE (INPUT VOLTAGE)

OK -- RETURN TO THE ORIGINAL INSPECTION FOR OTHER SYSTEM

2. INSPECT ECU TERMINAL VOLTAGE (INPUT VOLTAGE)

(a) Disconnect the F2 connector.





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

Standard voltage:





HINT
If any of the ECUs specified in the wiring diagram supplied power to the combination meter, the combination meter will output a waveform.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - NO. 3 JUNCTION BLOCK)
OK -- Continue to next step.

3. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)

(a) Disconnect the A60 (*1) or A26 (*2) connector.





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

Standard voltage:





*1: except TMC Made

*2: for TMC Made

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER - SKID CONTROL ECU)
OK -- Continue to next step.

4. INSPECT SKID CONTROL ECU (INPUT WAVEFORM)

(a) Check the input waveform.





(1) Reconnect the A60 (*1) or 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) Ignition switch on (IG).

(5) Turn the wheel slowly.

(6) Check the signal waveform according to the condition(s) in the table below.





*1: for TMC Made

*2: except TMC Made

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.

NG -- REPLACE SKID CONTROL ECU

OK -- REPLACE SKID CONTROL ECU

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

(a) Disconnect the A No. 3 junction block connector.





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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

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

(a) 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 B and C No. 3 junction block connectors.





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

Standard voltage:





(3) Reconnect the C No. 3 junction block connectors.





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

Standard voltage:





*1: for Separate Type Amplifier System

*2: with Navigation System

Result:





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

B -- SYSTEM CHECK
A -- Continue to next step.

7. SYSTEM CHECK

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

Result:





*1: with Navigation System

*2: for Separate Type Amplifier System

E -- CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER CIRCUIT)

D -- CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER CIRCUIT)

C -- CHECK HARNESS AND CONNECTOR (RADIO RECEIVER CIRCUIT)

B -- CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU CIRCUIT)
A -- Continue to next step.

8. CHECK HARNESS AND CONNECTOR (ECM CIRCUIT)

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





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

Standard resistance:





*1: for 2AR-FE

*2: for 2GR-FE

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM

9. CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU CIRCUIT)

(a) Disconnect the E60 connector.





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

Standard resistance:





*: with Tire Pressure Warning System

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE TIRE PRESSURE WARNING ECU

10. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER CIRCUIT)

(a) Disconnect the F8 connector.





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

Standard resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE RADIO RECEIVER ASSEMBLY

11. CHECK HARNESS AND CONNECTOR (NAVIGATION RECEIVER CIRCUIT)

(a) Disconnect the F13 connector.





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

Standard resistance:





*: with Navigation System

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE NAVIGATION RECEIVER ASSEMBLY

12. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER CIRCUIT)

(a) Disconnect the F19 connector.





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

Standard resistance:





*: for Separate Type Amplifier System

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE STEREO COMPONENT AMPLIFIER

13. SYSTEM CHECK

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

Standard resistance:





*1: with Smart Key System

C -- CHECK HARNESS AND CONNECTOR (MAIN BODY ECU CIRCUIT)

B -- CHECK HARNESS AND CONNECTOR (TCM CIRCUIT)
A -- Continue to next step.

14. CHECK HARNESS AND CONNECTOR (ECM CIRCUIT)

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





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

Standard resistance:





*1: for 2GR-FE

*2: for 2AR-FE

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM

15. CHECK HARNESS AND CONNECTOR (TCM CIRCUIT)

(a) Disconnect the C56 connector.





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

Standard resistance:





*: for 2GR-FE

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE TCM

16. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU CIRCUIT)

(a) Disconnect the E8 connector.





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

Standard resistance:





*: with Smart Key System

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU

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

(a) Disconnect the F2 connector.





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

Standard resistance:





*1: except TMC Made

*2: for TMC Made

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER ASSEMBLY