DESCRIPTION
The combination meter assembly receives vehicle speed signals from the brake booster with master cylinder assembly (skid control ECU) via the CAN communication line. The wheel speed sensors output voltages that vary according to the vehicle speed. The brake booster with master cylinder assembly (skid control ECU) supplies power to the wheel speed sensors. The brake booster with master cylinder assembly (skid control ECU) calculates the vehicle speed based on the pulses of the voltage.
WIRING DIAGRAM
| *1 | Brake Booster with Master Cylinder Assembly (Skid Control ECU) |
| *2 | Combination Meter Assembly |
| *3 | CAN Communication Line |
CAUTION / NOTICE / HINT
Note
When replacing the combination meter assembly, make sure to replace it with a new one.
If the vehicle speed is outside the allowable range when tested, perform the operation check.
Tech Tips
Before starting the following inspection, check tire size and tire air pressure.
PROCEDURE
CHECK FOR DTC (CAN COMMUNICATION SYSTEM)
Check if CAN communication DTCs are output.
| OK |
|---|
| CAN communication DTCs are not output. |
| Result | |||
|---|---|---|---|
|
| NG |
|
GO TO CAN COMMUNICATION SYSTEM Click here |
| OK |
|
CHECK FOR DTC (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)
Check for DTCs.
| OK |
|---|
| No DTCs are output. |
| Result | |||
|---|---|---|---|
|
| NG |
|
GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM Click here |
| OK |
|
PERFORM ACTIVE TEST USING GTS (SPEED METER OPERATION)
Using the GTS, perform the Active Test.
| Tester Display | Measurement Item | Control Range | Diagnostic Note |
|---|---|---|---|
| Speed Meter Operation | Speedometer |
|
There is a deviation in the values displayed on the speedometer display (Control range → Speedometer)
for km/h (except Australia):
for km/h (for Australia):
for mph: |
| Tester Display |
|---|
| Speed Meter Operation |
| OK |
|---|
| Speedometer indication is normal. |
| Result | |||
|---|---|---|---|
|
| NG |
|
REPLACE COMBINATION METER ASSEMBLY Click here |
| OK |
|
READ VALUE USING GTS (VEHICLE SPEED METER)
Using the GTS, read the Data List.
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| Vehicle Speed Meter | Vehicle speed | Min.: 0 km/h (0 mph), Max.: 255 km/h (158 mph) | Almost the same as actual vehicle speed | - |
| Tester Display |
|---|
| Vehicle Speed Meter |
Tech Tips
When the Data List values of the ECUs match, an internal malfunction of the combination meter assembly is suspected.
When the Data List values of the ECUs do not match, a signal output error of the brake booster with master cylinder assembly (skid control ECU) or an internal malfunction of the combination meter assembly is suspected.
| OK |
|---|
| Vehicle speed displayed on the GTS is almost the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer). |
| Result | |||
|---|---|---|---|
|
| OK |
|
REPLACE COMBINATION METER ASSEMBLY Click here |
| NG |
|
READ VALUE USING GTS (VEHICLE SPEED)
Using the GTS, read the Data List.
| Tester Display | Measurement Item | Normal Condition | Reference Value | Diagnostic Note |
|---|---|---|---|---|
| Vehicle Speed | Vehicle speed | Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) | Almost the same as actual vehicle speed | - |
| Tester Display |
|---|
| Vehicle Speed |
| OK |
|---|
| Vehicle speed displayed on the GTS is almost the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer). |
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| B |
|
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) Click here |
| C |
|
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) Click here |
| A |
|
CHECK COMBINATION METER ASSEMBLY
Replace the combination meter assembly.
Check that the operation of the speedometer returns to normal.
| OK |
|---|
| The operation of the speedometer returns to normal. |
| Result | ||||||||
|---|---|---|---|---|---|---|---|---|
|
| A |
|
END (COMBINATION METER ASSEMBLY IS DEFECTIVE) |
| B |
|
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) Click here |
| C |
|
REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY (SKID CONTROL ECU) Click here |