Speed Signal Circuit: Procedure

1. Disconnect the I18 combination meter assembly connector.
   Fig 1: Inspecting I18 Combination Meter Assembly Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   I18-9 (+S) - Body ground	Ignition switch to ON	4.5 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	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 

1. Reconnect the I18 combination meter assembly connector.
2. Disconnect the A49 skid control ECU connector.
   Fig 2: Inspecting A49 Skid Control ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A49-2 (SP1) - Body ground	Ignition switch to ON	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

   *a	Front view of wire harness connector (to Skid Control ECU)

NG → See step   4 

OK: Go to next step 

1. Check the input waveform.
   Fig 3: Inspecting I18 Combination Meter Assembly Connector Terminals With Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Reconnect the A49 skid control ECU connector.
   2. Remove the combination meter assembly with the connector(s) still connected.
   3. Connect an oscilloscope to terminal I18-8 (SI) and body ground.
   4. Turn the ignition switch to ON.
   5. Turn the wheel slowly.
   6. 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	Wheel being rotated

      TEXT IN ILLUSTRATION
      
      

      *a	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 

1. Disconnect the I18 combination meter assembly and A49 skid control ECU connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A49-2 (SP1) - I18-8 (SI)	Always	Below 1 Ω
   A49-2 (SP1) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   17 

1. Disconnect the I124 junction connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I18-9 - I124-18	Always	Below 1 Ω
   I18-9 - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. 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.

   1. Disconnect the I124 junction connector.
   2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection	Condition	Specified Condition
      I124-21 - Body ground	Ignition switch to ON	4.5 to 14 V
      I124-19 - Body ground	Ignition switch to ON	4.5 to 14 V
      I124-17 - Body ground	Ignition switch to ON	4.5 to 14 V
      I124-20 - Body ground	Ignition switch to ON	4.5 to 14 V
      I124-16 - Body ground	Ignition switch to ON	4.5 to 14 V
      I124-16 - Body ground	Ignition switch to ON	4.5 to 14 V
      I124-16 - Body ground	Ignition switch to ON	4.5 to 14 V

      Result

      Result	Proceed to
      Voltage is not present in one circuit.	A
      Voltage is present in all the circuits.	B

B → REPLACE JUNCTION CONNECTOR (INSTRUMENT PANEL WIRE) 

A: Go to next step 

1. Select the circuit for which voltage was not present in step 6.

   Result

   Tester Connection	System that uses the circuit	Proceed to
   I124-21 - Body ground	Smart key system*1	A
   I124-19 - Body ground	Audio/Visual system*2	B
   I124-17 - Body ground	Audio/Visual system*3, *4, *5, or Navigation system*6	C
   I124-20 - Body ground	Safety connect system*7	D
   I124-16 - Body ground	SFI system	E
   I124-16 - Body ground	Lighting system*8	E
   I124-16 - Body ground	U660E automatic transaxle system	E

   • *1: w/ Smart Key System
   • *2: for 10 Speakers
   • *3: for Radio Receiver Type
   • *4: for Radio and Display Type (w/o Intuitive Parking Assist System)
   • *5: for Radio and Display Type (w/ Intuitive Parking Assist System)
   • *6: for Navigation Receiver Type
   • *7: w/ Manual (SOS) Switch
   • *8: w/ Automatic Headlight Beam Level Control System

B → See step   9 

C → See step   10 

D → See step   11 

E → See step   12 

A: Go to next step 

1. Disconnect the I78 certification ECU (smart key ECU assembly) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I78-27 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   18 

1. Disconnect the I69 stereo component amplifier assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I69-11 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   20 

1. Disconnect the I150 radio receiver assembly*1, I155 radio and display receiver assembly*2, or I67 navigation ECU sub-assembly*3, *4 connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I150-17 (SPD)*1 - Body ground	Always	10 kΩ or higher
   I155-17 (SPD)*2 - Body ground	Always	10 kΩ or higher
   I67-17 (SPD)*3 - Body ground	Always	10 kΩ or higher
   I67-17 (SPD)*4 - Body ground	Always	10 kΩ or higher

   • *1: for Radio Receiver Type
   • *2: for Radio and Display Type (w/o Intuitive Parking Assist System)
   • *3: for Radio and Display Type (w/ Intuitive Parking Assist System)
   • *4: for Navigation Receiver Type

   Result

   Result	Proceed to
   OK (for Radio Receiver Type)	A
   OK (for Radio and Display Type (w/o Intuitive Parking Assist System)	B
   OK (for Radio and Display Type (w/ Intuitive Parking Assist System)	C
   OK (for Navigation Receiver Type)	C
   NG	D

B → See step   25 

C → See step   19 

D → REPAIR OR REPLACE HARNESS OR CONNECTOR 

A → See step   22 

1. Disconnect the I135 DCM (telematics transceiver) connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   I135-10 (SPDP) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   27 

1. Select the circuit for which voltage was not present in step 6.

   Result

   Tester Connection	System that uses the circuit	Proceed to
   I124-16 - Body ground	SFI system	A
   I124-16 - Body ground	Lighting system	B
   I124-16 - Body ground	U660E Automatic Transaxle system	C

B → See step   14 

C → See step   15 

A: Go to next step 

1. Disconnect the A25 ECM connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A25-57 (SPD)*1 - Body ground	Always	10 kΩ or higher
   A25-10 (SPD)*2 - Body ground	Always	10 kΩ or higher

   • *1: for 2AR-FE
   • *2: for 2GR-FE

   Result

   Result	Proceed to
   OK (for 2AR-FE)	A
   OK (for 2GR-FE)	B
   NG	C

B → See step   26 

C → REPAIR OR REPLACE HARNESS OR CONNECTOR 

A → See step   24 

1. Disconnect the A34 headlight leveling ECU assembly connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A34-16 (SPDR) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   21 

1. Disconnect the E7 TCM connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E7-3 (SPD) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   23