Toyota Tacoma manuals

Toyota Corolla Repair Manual: Check open circuit

  1. For the open circuit in the wire harness in fig. 1, Perform a resistance check in step (b) or a voltage check in step (c) to locate the section.

  1. Check the resistance.
  1.  Disconnect connectors a and c and measure the resistance between them.

    Resistance: 1 Ω or less

Hint

: measure the resistance while lightly shaking the wire harness vertically and horizontally. In the case of fig. 2: Between terminal 1 of connector a and terminal 1 of connector c " 10 kΩ

or higher between terminal 2 of connector a and terminal 2 of connector c " below 1 Ω

therefore, the cause is an open circuit between terminal 1 of connector a and terminal 1 of connector c.

  1. Disconnect connector b and measure the resistance between the connectors.

    In the case of fig. 3: Between terminal 1 of connector a and terminal 1 of connector b1 " below 1 w between terminal 1 of connector b2 and terminal 1 of connector c " 10 kw therefore, the cause is an open circuit between terminal 1 of connector b2 and terminal 1 of connector c.

  1. Check the voltage.
  1.  In a circuit in which voltage is applied (to the ecu connector terminal), an open circuit can be checked by conducting a voltage check.

    As shown in fig. 4, With each connector still connected, measure the voltage between the body ground and terminal 1 of connector a at the ecu 5 v output terminal, terminal 1 of connector b, and terminal 1 of connector c, in that order.

  2.  If the results are: 5 v: between terminal 1 of connector a and body ground 5 v: between terminal 1 of connector b and body ground 0 v: between terminal 1 of connector c and body ground therefore, the cause is an open circuit in the wire harness between terminal 1 of connector b and terminal 1 of connector c.

Check short circuit

Basic inspection
Resistance measuring condition of electronic parts  unless stated, all resistance is measured at an ambient temperature of 20 c (68 F). As the resistance may be outside the specifi ...

Check short circuit
If the wire harness is ground shorted as shown in fig. 5, Locate the section by conducting a resistance check with the body ground in step (b). Check the resistance with the body grou ...

Other materials:

Overhaul
Hint: components: 1. Drain manual transaxle oil (m/t transaxle) torque: 39.2 Nvm (400 Kgfcm, 29 ftlbf) 2. Drain automatic transaxle fluid (a/t transaxle) torque: 17.5 Nvm (178 Kgfcm, 13 ftlbf) 3. Remove front wheel 4. Remove engine under cover lh 5. Remove front axle hub lh nut U ...

Engine immobilizer system
The vehicles keys have built-in transponder chips that prevent the engine from starting if a key has not been previously registered in the vehicles on-board computer. Never leave the keys inside the vehicle when you leave the vehicle. Vehicles without a smart key system: The indicator light ...

Mechanical system tests
1. Perform mechanical system tests Measure the stall speed. The object of this test is to check the overall performance of the transaxle and engine by measuring the stall speeds in the d and r positions. Notice: Do the test at normal operating atf temperature 50 to 80 c (122 to ...

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