Speedometer Malfunction: Procedure
- PERFORM ACTIVE TEST USING TECHSTREAM (SPEED METER OPERATION)
- Connect Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the tester ON.
- Enter the following menus: Body Electrical / Combination Meter / Active Test.
- Check the operation by referring to the table below.COMBINATION METER:
Tester Display Test Part Control Range Diagnostic Note Speed Meter Operation Speedometer 0, 40, 80, 120 mph (*1) - 0, 40, 80, 120, 160, 200, 240 km/h (*2) *1: for U.S.A.
*2: except U.S.A.
OK
Needle indication is normal.
NG → REPLACE COMBINATION METER ASSEMBLY
OK: Go to next step
- READ VALUE USING TECHSTREAM (VEHICLE SPEED METER)
- Connect Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the tester ON.
- Enter the following menus: Body Electrical / Combination Meter / Data List.
- Check the values by referring to the values in the table below.COMBINATION METER:
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 same as actual speed (When driving) - OK
Vehicle speed displayed on the tester is almost the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).
NG → See step 3
OK → REPLACE COMBINATION METER ASSEMBLY
- READ VALUE USING TECHSTREAM (FL/FR/RL/RR WHEEL SPEED)
- Connect the Techstream to the DLC3.
- Turn the engine switch on (IG).
- Turn the tester ON.
- Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.
- Check the values by referring to the table below.ABS/VSC/TRAC:
Tester Display Measurement Item/Range Normal Condition Diagnostic Note FR Wheel Speed Vehicle speed/Min.: 0 mph (0 km/h), Max.: 202 mph (326 km/h) Almost the same as actual vehicle speed (Speedometer tester) - FL Wheel Speed Vehicle speed/Min.: 0 mph (0 km/h), Max.: 202 mph (326 km/h) Almost the same as actual vehicle speed (Speedometer tester) - RR Wheel Speed Vehicle speed/Min.: 0 mph (0 km/h), Max.: 202 mph (326 km/h) Almost the same as actual vehicle speed (Speedometer tester) - RL Wheel Speed Vehicle speed/Min.: 0 mph (0 km/h), Max.: 202 mph (326 km/h) Almost the same as actual vehicle speed (Speedometer tester) - OK
Vehicle speed displayed on the tester is almost the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).
NG → GO TO BRAKE CONTROL SYSTEM
OK: Go to next step
- INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)
- Disconnect the A58 connector.
- Measure the voltage according to the value(s) in the table below.
Standard voltage
Tester Connection Condition Specified Condition A58-11 (SP1) -
Body groundEngine switch on (IG) 10 to 14 V
NG → See step 6
OK: Go to next step
- INSPECT SKID CONTROL ECU (INPUT WAVEFORM)
- Check the input signal waveform.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
- Reconnect the A58 connector.
- Remove the combination meter assembly with connector(s) still connected.
- Connect the oscilloscope to the terminals J34-17 (SI) and body ground.
- Engine switch on (IG).
- Turn the wheel slowly.
- 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.
NG → REPLACE SKID CONTROL ECU
OK → REPLACE COMBINATION METER ASSEMBLY
- Check the input signal waveform.
- CHECK HARNESS AND CONNECTOR (COMBINATION METER - SKID CONTROL ECU)
- Disconnect the A58 and J34 connectors.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
Tester Connection Condition Specified Condition A58-11 (SP1) - J34-17 (SI) Always Below 1 Ω A58-11 (SP1) - Body ground Always 10 kΩ or higher
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → REPLACE COMBINATION METER ASSEMBLY