Speed Signal Circuit: Procedure
- INSPECT ECU TERMINAL VOLTAGE (INPUT VOLTAGE)
- Disconnect the F15 connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition F15-3 (+S) - Body ground Engine switch on (IG) 4.5 to 14 V TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Combination Meter Assembly)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 → See step 5
OK: Go to next step
- INSPECT COMBINATION METER ASSEMBLY (OUTPUT VOLTAGE)
- Reconnect the F15 connector.
- Disconnect the A44 connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition A44-11 (SP1) - Body ground Engine switch on (IG) 11 to 14 V TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Skid Control ECU)
NG → See step 4
OK: Go to next step
- INSPECT SKID CONTROL ECU (INPUT WAVEFORM)
- Check the input waveform.
- Reconnect the A44 connector.
- Remove the combination meter assembly with the connector(s) still connected.
- Connect an oscilloscope to terminal F15-4 (SI) and body ground.
- Turn the 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) TEXT IN ILLUSTRATION*1 Component with harness connected
(Combination Meter Assembly)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 → See step 16
OK → See step 17
- Check the input waveform.
- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - SKID CONTROL ECU)
- Disconnect the F15 and A44 connectors.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A44-11 (SP1) - F15-4 (SI) Always Below 1 Ω A44-11 (SP1) - Body ground Always 10 kΩ or higher TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Combination Meter Assembly)*2 Front view of wire harness connector
(to Skid Control ECU)
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 17
- CHECK HARNESS AND CONNECTOR (COMBINATION METER ASSEMBLY - JUNCTION BLOCK)
- Disconnect the F93 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition F15-3 (+S) - F93-57 Always Below 1 Ω F15-3 (+S) - Body ground Always 10 kΩ or higher TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Junction Block)*2 Front view of wire harness connector
(to Combination Meter Assembly)
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- CHECK HARNESS AND CONNECTOR (JUNCTION BLOCK)
- Inspect for a short in the circuit that is connected to the junction block connector shown in the wiring diagram.
HINT:
If voltage is not present, it is possible that an ECU or circuit has a malfunction. The malfunctioning ECU or circuit will be diagnosed in the following steps.
- Disconnect the junction block connector.
- Measure the voltage according to the value(s) in the table below.
Standard Voltage
Tester Connection Condition Specified Condition F93-87 - Body ground Engine switch on (IG) 4.5 to 14 V F93-37 - Body ground Engine switch on (IG) 4.5 to 14 V F93-27 - Body ground Engine switch on (IG) 4.5 to 14 V F93-47 - Body ground Engine switch on (IG) 4.5 to 14 V F93-67 - Body ground Engine switch on (IG) 4.5 to 14 V F93-77 - Body ground Engine switch on (IG) 4.5 to 14 V F93-88 - Body ground Engine switch on (IG) 4.5 to 14 V TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Junction Block)Result
Result Proceed to Voltage is not present in one circuit. A Voltage is present in all the circuits. B
B → REPLACE JUNCTION BLOCK
A: Go to next step
- Inspect for a short in the circuit that is connected to the junction block connector shown in the wiring diagram.
- SYSTEM CHECK
- Select the circuit for which voltage was not present in step 6.
Result
Tester Connection System that Uses the Circuit Proceed to F93-87 - Body ground Tire Pressure Warning System*1 A F93-37 - Body ground Smart Access System with Push-button Start System B F93-27 - Body ground Separate Type Amplifier System*2 B F93-47 - Body ground Audio and Visual System or Navigation System*3 B F93-67 - Body ground SFI System, Automatic Transaxle System B F93-77 - Body ground Wiper and Washer System*4 B F93-88 - Body ground Lexus Enform System*5 C - *1: w/ Tire Pressure Warning System
- *2: for Separate Type Amplifier System
- *3: w/ Navigation System
- *4: w/ Auto Wiper System
- *5: w/ Manual (SOS) Switch
B → See step 9
C → See step 15
A: Go to next step
- Select the circuit for which voltage was not present in step 6.
- CHECK HARNESS AND CONNECTOR (TIRE PRESSURE WARNING ECU CIRCUIT)
- Disconnect the F53 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition F53-2 (SPD) - Body ground Always 10 kΩ or higher TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Tire Pressure Warning ECU)
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 20
- SYSTEM CHECK
- Select the circuit for which voltage was not present in step 6.
Result
Tester Connection System that Uses the Circuit Proceed to F93-37 - Body ground Smart Access System with Push-button Start System A F93-27 - Body ground Separate Type Amplifier System*1 B F93-47 - Body ground Audio and Visual System or Navigation System*2 C F93-67 - Body ground SFI System, Automatic Transaxle System D F93-77 - Body ground Auto Wiper System*3 E - *1: for Separate Type Amplifier System
- *2: w/ Navigation System
- *3: w/ Auto Wiper System
B → See step 11
C → See step 12
D → See step 13
E → See step 14
A: Go to next step
- Select the circuit for which voltage was not present in step 6.
- CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU CIRCUIT)
- Disconnect the F8 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition F8-23 (SPD) - Body ground Always 10 kΩ or higher TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Power Management Control ECU)
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 18
- CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER CIRCUIT)
- Disconnect the O15*1 or O33*2 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition O15-2 (SPD)*1 - Body ground Always 10 kΩ or higher O33-11 (SPD)*2 - Body ground Always 10 kΩ or higher - *1: w/ Navigation System
- *2: w/o Navigation System
TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Stereo Component Amplifier (w/ Navigation System))*2 Front view of wire harness connector
(to Stereo Component Amplifier (w/o Navigation System))
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 24
- CHECK HARNESS AND CONNECTOR (RADIO RECEIVER, DISPLAY AND NAVIGATION MODULE DISPLAY)
- Disconnect the G9 or G4*1 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G9-3 (SPD) - Body ground Always 10 kΩ or higher G4-18 (SPD)*1 - Body ground Always 10 kΩ or higher - *1: w/ Navigation System
TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Radio Receiver)*2 Front view of wire harness connector
(to Display and Navigation Module Display)Result
Result Proceed to OK (for Radio Receiver Circuit) A OK (for Display and Navigation Module Display Circuit for DVD) B OK (for Display and Navigation Module Display Circuit for HDD) C NG D
B → See step 25
C → See step 27
D → REPAIR OR REPLACE HARNESS OR CONNECTOR
A → See step 23
- CHECK HARNESS AND CONNECTOR (ECM CIRCUIT, TCM CIRCUIT)
- Disconnect the A43 or D2 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition A43-13 (SPD) - Body ground Always 10 kΩ or higher D2-3 (SPD) - Body ground Always 10 kΩ or higher TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to ECM)*2 Front view of wire harness connector
(to TCM)Result
Result Proceed to OK (for 2GR-FE SFI System) A OK (for U660E Automatic Transaxle System) B OK (for U660F Automatic Transaxle System) C NG D
B → See step 26
C → See step 21
D → REPAIR OR REPLACE HARNESS OR CONNECTOR
A → See step 19
- CHECK HARNESS AND CONNECTOR (WINDSHIELD WIPER SWITCH ASSEMBLY CIRCUIT)
- Disconnect the F42 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition F42-6 (SPD) - Body ground Always 10 kΩ or higher TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to Windshield Wiper Switch Assembly)
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 22
- CHECK HARNESS AND CONNECTOR (DCM (TELEMATICS TRANSCEIVER) CIRCUIT)
- Disconnect the G25 connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition G25-10 (SPDP) - Body ground Always 10 kΩ or higher TEXT IN ILLUSTRATION*1 Front view of wire harness connector
(to DCM (Telematics Transceiver))
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK → See step 28
- REPLACE SKID CONTROL ECU. Refer to REMOVAL
- REPLACE COMBINATION METER ASSEMBLY. Refer to REMOVAL
- REPLACE POWER MANAGEMENT CONTROL ECU. Refer to REMOVAL
- REPLACE ECM (for 2GR-FE). Refer to REMOVAL
- REPLACE TIRE PRESSURE WARNING ECU. Refer to REMOVAL
- REPLACE TCM (for U660F). Refer to REMOVAL
- REPLACE WINDSHIELD WIPER SWITCH ASSEMBLY. Refer to REMOVAL
- REPLACE RADIO RECEIVER. Refer to REMOVAL
- REPLACE STEREO COMPONENT AMPLIFIER. Refer to REMOVAL
- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY (for DVD). Refer to REMOVAL
- REPLACE TCM (for U660E). Refer to REMOVAL
- REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY (for HDD). Refer to REMOVAL
- REPLACE DCM (TELEMATICS TRANSCEIVER). Refer to REMOVAL