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Home >> Toyota >> 2012 >> Yaris Hatchback L4-1.5L (1NZ-FE) >> Repair and Diagnosis >> Instrument Panel, Gauges and Warning Indicators >> Testing and Inspection >> Component Tests and General Diagnostics >> Speed Signal Circuit (from 07/2011)

Speed Signal Circuit (from 07/2011)





METER / GAUGE / DISPLAY: METER / GAUGE SYSTEM (for Hatchback): Speed Signal Circuit
- Speed Signal Circuit

DESCRIPTION

w/ ABS:

* 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 brake actuator assembly supplies power to the vehicle speed sensor. The brake actuator assembly detects vehicle speed signals based on the pulses of the voltage. The brake actuator assembly 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 brake actuator assembly. 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.

w/o ABS:

* The meter CPU receives vehicle speed signals from this circuit. The speedometer sensor detects the voltage that varies according to the vehicle speed. The speedometer sensor detects vehicle speed signals based on the pulses of the voltage. The speedometer sensor 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 speedometer sensor. 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





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT COMBINATION METER ASSEMBLY (INPUT VOLTAGE)

(a) Disconnect the D100 combination meter assembly connector.





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

Standard Voltage:





Text in Illustration





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

(c) Reconnect the combination meter assembly connector.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)
OK -- Continue to next step.

2. SYSTEM CHECK

(a) Check the vehicle specifications.

Result





B -- INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)
A -- Continue to next step.

3. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE) Speedometer Malfunction (from 07/2011)

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY)
OK -- Continue to next step.

4. INSPECT COMBINATION METER ASSEMBLY (INPUT WAVEFORM) Speedometer Malfunction (from 07/2011)

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal (from 07/2011)

OK -- REPLACE COMBINATION METER ASSEMBLY Removal (from 07/2011)

5. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)

(a) Disconnect the C57 speedometer sensor connector.





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

Standard Voltage:





Text in Illustration





(c) Reconnect the C57 speedometer sensor connector.

NG -- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SPEEDOMETER SENSOR)
OK -- Continue to next step.

6. INSPECT COMBINATION METER ASSEMBLY (INPUT WAVEFORM)

(a) Check the input waveform.





(1) Remove the combination meter assembly with the connector(s) still connected.

(2) Connect an oscilloscope to terminal D100-5 (SI) and body ground.

(3) Turn the ignition switch to ON.

(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
As the vehicle speed increases, the cycle of the waveform narrows.

Text in Illustration





NG -- REPLACE SPEEDOMETER SENSOR

OK -- REPLACE COMBINATION METER ASSEMBLY Removal (from 07/2011)

7. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - BRAKE ACTUATOR ASSEMBLY) Speedometer Malfunction (from 07/2011)

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER ASSEMBLY Removal (from 07/2011)

8. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SPEEDOMETER SENSOR)

(a) Disconnect the D100 combination meter assembly connector.

(b) Disconnect the C57 speedometer sensor connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE COMBINATION METER ASSEMBLY Removal (from 07/2011)

9. CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 3B instrument panel junction block assembly connector.

(b) Disconnect the D100 combination meter assembly connector.

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

Standard Resistance:





(d) Reconnect the 3B instrument panel junction block assembly connector.

(e) Reconnect the D100 combination meter assembly connector.

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

10. INSPECT ECM

(a) Disconnect the 3C instrument panel junction block assembly connector.





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

Standard Voltage:





Text in Illustration





(c) Reconnect the 3C instrument panel junction block assembly connector.

NG -- CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - ECM)
OK -- Continue to next step.

11. SYSTEM CHECK

(a) Check the vehicle specifications.

Result





B -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Removal (from 07/2011)
A -- Continue to next step.

12. INSPECT POWER STEERING ECU ASSEMBLY

(a) Disconnect the 3A instrument panel junction block assembly connector.





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

Standard Voltage:





Text in Illustration





(c) Reconnect the 3A instrument panel junction block assembly connector.

NG -- CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - POWER STEERING ECU ASSEMBLY)

OK -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Removal (from 07/2011)

13. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - ECM)

(a) Disconnect the 3C instrument panel junction block assembly connector.

(b) Disconnect the A72 ECM connector.

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

Standard Resistance:





(d) Reconnect the 3C instrument panel junction block assembly connector.

(e) Reconnect the A72 ECM connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE ECM Removal (from 07/2011)

14. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - POWER STEERING ECU ASSEMBLY)

(a) Disconnect the 3A instrument panel junction block assembly connector.

(b) Disconnect the D104 power steering ECU connector.

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

Standard Resistance:





(d) Reconnect the 3A instrument panel junction block assembly connector.

(e) Reconnect the D104 power steering ECU connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE POWER STEERING ECU ASSEMBLY Removal (from 07/2011)
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