Combination Meter: Inspection

WARNING: This page is about a different car, the 2002 Toyota Celica. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Tire wear and tire over or under inflation will increase the indication error.

Fig 1: Speedometer Allowable Indication Error

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Inspect speedometer on-vehicle :
Using a speedometer tester, inspect the speedometer for allowable indication error and check the operation of the odometer.

If error is excessive, replace the speedometer.
Inspect speedometer resistance :
Measure the resistance between terminals with fixing pointer to the stopper.

Fig 2: Locating Speedometer Test Probing Locations
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Fig 3: Speedometer Resistance Specifications
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If resistance value is not as specified, replace the meter.
Inspect vehicle speed sensor operation :
1. Connect the positive (+) lead from the battery to terminal 1 and negative (-) lead to terminal 2.
  
  Fig 4: Testing Vehicle Speed Sensor
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the positive (+) lead from tester to terminal 3 and negative (-) lead to terminal 2.
3. Rotate shaft.
4. Check that there is voltage change from approx. 0 V to 11 V or more between terminals 2 and 3.
If operation is not as specified, replace the sensor.
Inspect tachometer on-vehicle :
CAUTION: Reversing the connection of the tachometer will damage the transistors and diodes inside.
1. Connect a tune-up test tachometer, and start the engine.
2. Compare the tester indications with tachometer indications.
RPM (DC 13.5 V, 25 °C (77 °F))

Fig 5: Tachometer Allowable Indication Error
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If error is excessive, replace the tachometer.
Inspect tachometer resistance :
Measure the resistance between terminals with fixing pointer to the stopper.

Fig 6: Locating Tachometer Test Probing Locations
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 7: Tachometer Resistance Specifications
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If resistance value is not as specified, replace the meter.
Inspect fuel receiver gauge operation :
1. Disconnect the connector from the sender gauge assembly.
2. Turn the ignition switch ON, check that the receiver gauge needle indicates EMPTY.
  
  Fig 8: Testing Fuel Receiver Gauge Operation (1 Of 2)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Connect terminals 2 and 3 of the wire harness side connector through a 3.4 W test bulb.
  
  Fig 9: Testing Fuel Receiver Gauge Operation (2 Of 2)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Turn the ignition switch ON, check that the bulb lights up and receiver gauge needle indicators EMPTY.
If operation is not as specified, inspect the sender gauge resistance.
Inspect fuel sender gauge resistance :
Measure the resistance between terminals 2 and 3 for each float position.

Fig 10: Measuring Fuel Sender Gauge Resistance
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Fig 11: Fuel Sender Gauge Specifications
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If resistance value is not as specified, replace the sender gauge.

If resistance value is as specified, replace the combination meter.
Inspect engine coolant temperature receiver gauge operation :
1. Disconnect the connector from the sender gauge.
2. Turn the ignition switch ON, check that the receiver gauge needle indicates COOL.
  
  Fig 12: Testing Engine Coolant Temperature Receiver Gauge (1 Of 2)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Ground terminal of the wire harness side connector through a 3.4 W test bulb.
  
  Fig 13: Testing Engine Coolant Temperature Receiver Gauge (2 Of 2)
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Turn the ignition switch ON, check that the bulb lights up and the receiver gauge needle moves toward the hot side.
If operation is not as specified, inspect the sender gauge.

Then recheck the system.
Inspect engine coolant temperature sender gauge resistance :
Connect the wire harness as shown in the illustration, see Fig 14, and adjust the ammeter pointer to indicate "0" using the slide rheostat, then read the rheostat indication.

Fig 14: Measuring Engine Coolant Temperature Sender Gauge Resistance
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Fig 15: Engine Coolant Temperature Sender Gauge Specifications
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If resistance value is not as specified, replace the engine coolant temperature sender gauge.

If resistance value is as specified, replace the combination meter.
Inspect low oil pressure warning light :
1. Disconnect the connector from the warning switch and ground terminal of the wire harness side connector.
  
  Fig 16: Testing Low Oil Pressure Warning Light
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Turn the ignition switch ON, check that the warning light lights up.
If the warning light does not light up, test the bulb or inspect wire harness.

NOTE: Oil pressure should be over 24.5 kPa (0.25 kgf/cm² , 3.55 psi) If operation is not as specified, replace the switch.

Inspect low oil pressure switch continuity :
1. Check that continuity exists between terminal and ground with the engine stopped.
  
  Fig 17: Testing Low Oil Pressure Switch
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check that no continuity exists between terminal and ground with the engine running.
Inspect brake warning system light :
1. Disconnect the connector from the brake fluid warning switch.
2. Connect terminals of the wire harness side of the level warning switch connector.
  
  Fig 18: Testing Brake Warning Light
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Start the engine, check that the warning light lights up. If the warning light does not light up, test the bulb or wire harness.
Inspect brake fluid level warning switch continuity :
1. Remove the reservoir tank cap and strainer.
2. Disconnect the connector.
3. Check that no continuity exists between terminals with the switch OFF (float up).
  
  Fig 19: Testing Brake Fluid Level Warning Switch
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
4. Use siphon, etc. to take fluid out of the reservoir tank.
5. Check that continuity exists between terminals with the switch ON (float down).
6. Pour the fluid back in the reservoir tank.
If operation is not as specified, replace the switch.
Inspect parking brake warning light :
1. Disconnect the connector from the parking brake switch.
2. Ground terminal of the wire harness side connector.
  
  Fig 20: Testing Parking Brake Warning Light
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Start the engine, check that the warning light lights up.
If the warning light does not light up, test the bulb or inspect wire harness.
Inspect parking brake switch continuity :
1. Check that continuity exists between terminal and switch body with the switch ON (switch pin released).
  
  Fig 21: Testing Parking Brake Switch
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Check that no continuity exists between terminal and switch body with the switch OFF (switch pin pushed in).
If operation is not as specified, replace the switch or inspect ground point.
Inspect open door warning light :
Disconnect the connector from the door courtesy switch, and ground terminal 1 of the wire harness side connector and check that the warning light lights up.

Fig 22: Testing Open Door Warning Light
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If the warning light does not light up, inspect the bulb or wire harness.
Inspect light control rheostat operation :
Gradually, turn the rheostat knob from the bright side to dark side and check that the resistance decreases from 10 k/Ohm to zero Ohms between terminal 2 and 1. (Rheostat knob turned to clockwise)

Fig 23: Testing Light Control Rheostat
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

If operation is not as specified, replace the rheostat light control.