Toyota Tacoma manuals

Toyota Corolla Repair Manual: Road test

1. Problem symptom confirmation

  1. Taking into consideration the results of the customer problem analysis, try to reproduce the symptoms of the trouble. If the problem is that the transaxle does not shift up, shift down, or the shift point is too high or too low conduct the following road test referring to the automatic shift schedule and simulate the problem symptoms.

2. Perform road test

Notice

: conduct the test at normal operating atf temperature 50 to 80 c (122 to 176 f).

  1. D position test shift into the d position and fully depress the accelerator pedal and check the following points:
  1.  check upshift operation.

    Check that 1 " 2, 2 " 3 and 3 " o/d upshift takes place, and that the shift points conform to the automatic shift schedule .

Hint

: o/d gear upshift prohibition control

O/d and 3rd gear lockup prohibition control

3Rd gear lockup prohibition control

  1.  check for shift shock and slip.

    Check for shock and slip at the 1 " 2, 2 " 3 and 3 " o/d upshift.

  2.  Check for abnormal noises and vibration.

    Run in d position lockup or o/d gear and check for abnormal noises and vibration.

Hint: the check for the cause of abnormal noises and vibration must be done very thoroughly as it could also be sure to loss of balance in the differential, torque converter, etc.

  1.  Check kickdown operation.

    Check that the possible kickdown vehicle speed limits for 2nd to 1st, 3rd to 2nd, o/d to 3rd kick downs conform to those indicated on the automatic shift schedule while driving through all gears with the shift lever in the d position .

  2.  Check for abnormal shock and slip at kickdown.
  3.  Check the lockup mechanism.

If there is a big jump in engine speed, there is no lockup.

  1.  2 position test shift into the 2 position and fully depress the accelerator pedal and check the following points:
  1.  check upshift operation.

    Check that the 1 " 2 upshift takes place and that the shift point conforms to the automatic shift schedule .

Hint

: there is no o/d upshift and lockup in the 2 position.

  1. Check engine braking.

    While running in the 2 position and 2nd gear, release the accelerator pedal and check the engine braking effect.

  2.  Check for abnormal noises during acceleration and deceleration, and for shock at upshift and downshift.
  1.  l position test shift into the l position and fully depress the accelerator pedal and check the following points:
  1.  check no upshift.

    While running in the l position, check that there is no upshift to 2nd gear.

  2.  Check engine braking.

    While running in the l position, release the accelerator pedal and check the engine braking effect.

  3.  Check for abnormal noises during acceleration and deceleration.
  1.  r position test shift into the r position and fully depress the accelerator pedal and check for slipping.

    Caution

    : before conducting this test ensure that the test area is free from people and obstruction.

  2. p position test stop the vehicle on a grade (more than 5), shift into the p position and release the parking brake.

    Check that the vehicle does not move.

Check mode procedure
1. Dtc check (check mode) Hint: handheld tester only: compared to the normal mode, the check mode has more sensing ability to detect malfunctions. Furthermore, the same diagnostic items which ar ...

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 an ...

Other materials:

Circuit description
Shifting from 1st to o/d is performed in combination with on and off of the shift solenoid valve s1 and s2 controlled by ecm. If an open or short circuit occurs in either of the solenoid valves, the ecm controls the remaining normal solenoid valve to allow the vehicle to be operated smoothly ...

Onvehicle inspection
1. Inspect drive belt Visually check the belt for excessive wear, frayed cords, etc. If any defect is found, replace the drive belt. Hint: cracks on the rib side of a belt are considered acceptable. If the missing chunks from the ribs are found on the belt, it should be replaced. 2 ...

Description
When troubleshooting obd ii vehicles, the only difference from the usual troubleshooting procedure is that you need to connect the vehicle to the obd ii scan tool complying with sae j1978 or the handheld tester, and read various data output from the vehicles ecm. Obd ii regulations re ...

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