Component Tests and General Diagnostics

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

DESCRIPTION

The combination meter assembly receives the vehicle speed signal from this circuit. The wheel speed sensors produce an output that varies according to the vehicle speed. The wheel speed sensor output is received by the skid control ECU, which uses this information to create the vehicle speed sensor signal*1. The vehicle speed sensor signal consists of pulses sent to the combination meter assembly from the skid control ECU. To create this signal, 12 V is output from IG2, which is behind a resistor in the combination meter assembly. This voltage is sent to the skid control ECU. The pulse signal is created by switching the transistor in the skid control ECU on and off, making the voltage on the wire drop to 0 V. A similar system is used for the output of this signal from the combination meter assembly via terminal +S. A voltage of 12 V or 5 V is applied to terminal +S from each ECU or relay that is connected to this terminal. The transistor in the combination meter assembly is controlled by the signal from the skid control ECU. When this transistor is turned on, this transistor makes the voltage supplied by the various ECUs (via their respective internal resistors) drop to 0 V. Each ECU connected to terminal +S of the combination meter assembly controls its respective system based on the pulse signal.

* *1: This vehicle speed sensor signal is created by the skid control ECU. There is no actual component that is referred to as the vehicle speed sensor. In addition, for some other systems, vehicle speed information may be exchanged using CAN communication.

HINT
This circuit is used for the systems connected to terminal +S. This signal is not used for combination meter assembly operation. Combination meter assembly components such as the speedometer operate using data received via CAN communication.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. INSPECT COMBINATION METER ASSEMBLY (INPUT VOLTAGE)

(a) Disconnect the D18 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.

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

2. INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)

(a) Disconnect the A4 brake actuator assembly connector.





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

Standard Voltage:





Text in Illustration





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

3. INSPECT BRAKE ACTUATOR 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 D18-11 (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 BRAKE ACTUATOR ASSEMBLY Removal

OK -- REPLACE COMBINATION METER ASSEMBLY Removal

4. CHECK HARNESS AND CONNECTOR (BRAKE ACTUATOR ASSEMBLY - COMBINATION METER ASSEMBLY)

(a) Disconnect the A4 brake actuator assembly connector.

(b) Disconnect the D18 combination meter assembly 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

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

(a) Disconnect the D18 combination meter assembly connector.

(b) Disconnect the 2A instrument panel junction block assembly connector.

(c) 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 (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Inspect for a short in the circuit that is connected to the instrument panel junction block assembly connector shown in the wiring diagram.

HINT
If the voltage is not as specified, it is possible that an ECU or circuit has a malfunction. The malfunctioning ECU or circuit will be diagnosed in the following steps.

(1) Disconnect the 2A and 2F instrument panel junction block assembly connectors.





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

Standard Voltage:





Text in Illustration





Result





B -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
A -- Continue to next step.

7. SYSTEM CHECK

(a) Select the circuit for which voltage was not as specified in the previous step 6.

Result





*1: w/ Smart Key System

*2: w/ Rain Sensor

*3: for Separate Type Amplifier System

*4: w/ Safety Connect System

*5: w/ Navigation System

*6: w/o Navigation System

D -- CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - JUNCTION CONNECTOR)

C -- CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - TIRE PRESSURE WARNING ECU)

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

8. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - TCM)

(a) Disconnect the 2F instrument panel junction block assembly connector.

(b) Disconnect the B2 TCM 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 TCM

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

(a) Disconnect the 2F instrument panel junction block assembly connector.

(b) Disconnect the A39 or A55 ECM connector.

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

Standard Resistance:

for 2GR-FE





for 1AR-FE





Result





C -- REPLACE ECM (for 1AR-FE) Removal

B -- REPLACE ECM (for 2GR-FE) Removal

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR

10. CHECK HARNESS AND CONNECTOR (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - TIRE PRESSURE WARNING ECU)

(a) Disconnect the 2A instrument panel junction block assembly connector.

(b) Disconnect the D82 tire pressure warning ECU 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 TIRE PRESSURE WARNING ECU Removal

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

(a) Disconnect the 2A instrument panel junction block assembly connector.

(b) Disconnect the D107 junction connector.

(c) 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.

12. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR)

(a) Inspect for a short in the circuit that is connected to the junction connector shown in the wiring diagram.

(1) Disconnect the D107 junction connector.





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

Standard Voltage:





*1: w/ Smart Key System
*2: w/ Rain Sensor
*3: for Separate Type Amplifier System
*4: w/ Safety Connect System

Text in Illustration





Result





B -- REPLACE JUNCTION CONNECTOR
A -- Continue to next step.

13. SYSTEM CHECK

(a) Select the circuit for which voltage was not as specified in the previous step 12.

Result





*1: w/ Smart Key System

*2: w/ Rain Sensor

*3: for Separate Type Amplifier System

*4: w/ Safety Connect System

*5: w/ Navigation System

*6: w/o Navigation System

E -- CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - NAVIGATION RECEIVER OR RADIO RECEIVER)

D -- CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - TELEMATICS TRANSCEIVER)

C -- CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - STEREO COMPONENT AMPLIFIER ASSEMBLY)

B -- CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - WINDSHIELD WIPER RELAY ASSEMBLY)
A -- Continue to next step.

14. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - POWER MANAGEMENT CONTROL ECU)

(a) Disconnect the D107 junction connector.

(b) Disconnect the D89 power management control ECU 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 POWER MANAGEMENT CONTROL ECU Removal

15. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - WINDSHIELD WIPER RELAY ASSEMBLY)

(a) Disconnect the D107 junction connector.

(b) Disconnect the D78 windshield wiper relay assembly 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 WINDSHIELD WIPER RELAY ASSEMBLY Removal

16. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - STEREO COMPONENT AMPLIFIER ASSEMBLY)

(a) Disconnect the D107 junction connector.

(b) Disconnect the L5 stereo component amplifier assembly 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 STEREO COMPONENT AMPLIFIER ASSEMBLY Removal

17. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - TELEMATICS TRANSCEIVER)

(a) Disconnect the D107 junction connector.

(b) Disconnect the D73 telematics transceiver 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 TELEMATICS TRANSCEIVER Removal

18. CHECK HARNESS AND CONNECTOR (JUNCTION CONNECTOR - NAVIGATION RECEIVER OR RADIO RECEIVER)

(a) w/ Navigation System

(1) Disconnect the D107 junction connector.

(2) Disconnect the D55 navigation receiver assembly connector.

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

Standard Resistance:





(b) w/o Navigation System

(1) Disconnect the D107 junction connector.

(2) Disconnect the D63 radio receiver assembly connector.

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

Standard Resistance:





Result





C -- REPLACE RADIO RECEIVER ASSEMBLY Removal

B -- REPLACE NAVIGATION RECEIVER ASSEMBLY Removal

A -- REPAIR OR REPLACE HARNESS OR CONNECTOR