Symptom Related Diagnostic Procedures

Checking poor shifting quality

Checking the gear system





Fault-tracing information

Checking the gear system
Problems that the customer may experience are hard shifts or slipping shifts. The following test-drive contains several different driving situations that may provoke these symptoms if the transmission is damaged.

Note! It is important that the transmission oil is above 70 °C before the test-drive starts!

Test 1
1. Driving at 100 km/h, 6th gear.
2. Perform a kickdown to 4th gear.
3. Let the transmission automatically shift up to 5th gear.
4. Let up the accelerator pedal and let the transmission shift up to 6th gear.

Test 2
1. Driving at 100 km/h, 6th gear.
2. Slight uphill grade, press accelerator pedal until you obtain shifting 6-5, not kickdown.

Test 3
1. Driving at 80 km/h.
2. Move the gear selector to position M and engage 6th gear.
3. Perform a kickdown and shift 6-5, 5-4, 4-3 at the same time.
4. Then upshift immediately to 6th gear.

Test 4
1. Driving with gear 4.
2. Let up the accelerator pedal so that downshift to 3rd gear takes place.

Test 5
1. Stationary vehicle, engine running, parking brake applied, brake activated with left foot, gear selector in position R.
2. Press down the accelerator pedal (brake still activated).

Note! Let up the accelerator pedal in case of noise or slipping.

Test 6
1. Stationary vehicle, engine running, parking brake applied, brake activated with left foot, gear selector in position D.
2. Press down the accelerator pedal (brake still activated).

Note! Let up the accelerator pedal in case of noise or slipping.

Test 7
1. Driving forward (gear position D).
2. Slow acceleration with gear shifts 1-2, 2-3, 3-4.
3. Release the accelerator pedal so that downshifting 4-3, 3-2, 2-1 occurs.

Test 8
1. Shift the gear selector to M and perform test 7 again with included engine braking in first gear.

Test 9
1. Driving with gear R.
2. Slow acceleration to 25 km/h.
If the symptoms hard shifts or slipping shifts arise during the test-drive, the transmission's control system must be replaced.

Other information
- Valve housing, B6304T4, TF-80SC AWD, B5254T5, TF-80SC Valve Housing

Is the function OK?

Yes - DONE

No - FAULT FOUND

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DONE - Fault-tracing information

FAULT FOUND - Replacing the control system

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Fault-tracing information
In certain cases, the automatic transmission's gearshifting quality be dependent on the engine's function. If the automatic transmission's gearshifting quality is poor, troubleshoot the engine's control system as well.

Continue - DONE

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Replacing the control system




The previous test indicates that there is a fault in the transmission control system. Replace the control system.
- Ignition off.

Other information
- Valve housing, B6304T4, TF-80SC AWD, B5254T5, TF-80SC Valve Housing

Continue - DONE

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