Speed Signal Circuit: Procedure

1. Disconnect the E55 connector.
   Fig 1: Inspecting ECU Terminal Voltage (Input Voltage)

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

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   E55-36 (+S) - Body ground	Ignition switch ON	4.5 to 14 V

   HINT: 

   If any of the ECUs specified in the wiring diagram supplies power to the combination meter, the combination meter will output a waveform.

NG → See step   5 

OK: Go to next step 

1. Reconnect the E55 connector.
   Fig 2: Inspecting A38 Skid Control ECU Connector Terminal SP1

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the A38 connector.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   A38-11 (SP1) - Body ground	Ignition switch ON	11 to 14 V

NG → See step   4 

OK: Go to next step 

1. Check the input waveform.
   Fig 3: Inspecting E55 Combination Meter Connector Terminal SI With Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Reconnect the A38 connector.
   2. Remove the combination meter with the connector(s) still connected.
   3. Connect the oscilloscope to terminal E55-35 (SI) and body ground.
   4. Turn the ignition switch to ON.
   5. Turn a drive 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	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 → See step   12 

OK → See step   11 

1. Disconnect the E55 connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A38-11 (SP1) - E55-35 (SI)	Always	Below 1 Ω
   A38-11 (SP1) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   11 

1. Inspect for a short in the circuits connected to the combination meter 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 E55 and 2E and E32*1 and E44*2 connectors.
   2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection	Condition	Specified Condition
      E55-36 (+S) - Body ground	Always	10 kΩ or higher

      • *1: w/ Radio Receiver
      • *2: w/ Tire Pressure Warning System

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

HINT: 

For vehicles not equipped with a tire pressure warning system, proceed to the next step.

1. Reconnect the E44 connector.
   Fig 4: Checking E44 Tire Pressure Warning ECU Connector Terminal SPD

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E44-2 (SPD) - Body ground	Always	10 kΩ or higher

   HINT: 

   If the result is not as specified, there may be a short in the tire pressure warning ECU.

NG → See step   13 

OK: Go to next step 

HINT: 

For vehicles not equipped with a radio receiver, proceed to the next step.

1. Reconnect the E32 connector.
   Fig 5: Checking E32 Radio Receiver Connector Terminal SPD

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E32-3 (SPD) - Body ground	Always	10 kΩ or higher

   HINT: 

   If the result is not as specified, there may be a short in the radio receiver.

NG → See step   14 

OK: Go to next step 

1. Inspect for a short in the circuit that is connected to the combination meter 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 2C, 2D, and 2E connectors.
      Fig 6: Checking Driver Side Junction Block 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	Switch Condition	Specified Condition
      2C-8*1 - Body ground	Ignition switch ON	4.5 to 14 V
      2D-8 - Body ground	Ignition switch ON	4.5 to 14 V

      *1: w/ Sliding Roof

      Result

      Result	Proceed to
      All values are within the specified range.	A
      Malfunction between the ECM and driver side junction block.	B
      Malfunction between the sliding roof control ECU and driver side junction block.	C
      Malfunction between the stereo component amplifier and driver side junction block.

B → See step   9 

C → See step   10 

A → REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY 

1. Disconnect the A37 connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A37-8*1 (SPD) - Body ground	Always	10 kΩ or higher
   A37-38*2 (SPD) - Body ground	Always	10 kΩ or higher

   Result

   Result	Proceed to
   OK (for 2AZ-FE)	A
   OK (for 2ZR-FE)	B
   NG	C

   • *1: for 2AZ-FE
   • *2: for 2ZR-FE

B → See step   16 

C → REPAIR OR REPLACE HARNESS OR CONNECTOR 

A → See step   15 

HINT: 

For vehicles not equipped with a sliding roof, proceed to the next step.

1. Reconnect the 2C, 2D, and 2E connectors.
2. Disconnect the O2 connector.
   Fig 7: Identifying 02 Connector Terminal

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3. Turn the ignition switch to ON.
4. Check that the speed signal circuit operates normally.

   Result

   Result	Proceed to
   Speed signal circuit operates normally.	OK
   Speed signal circuit does not operate normally.	NG

   HINT: 

   If the speed signal circuit operates normally after disconnecting the sliding roof control ECU, there may be a short in the sliding roof control ECU.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   17