Incorrect Gear Ratio
Incorrect gear ratio
Checking the oil quality and the oil level in the transmission
Note! Transmission fluid quality and level are extremely important for the function of the transmission. Therefore it is imperative that these are correct. In addition the oil level is dependent on oil temperature.
- Ignition on
- Read off the oil temperature.
Check the transmission oil level. If the oil level is low check for leakage. Top up with oil.
Check the quality of the oil.
Replace the transmission fluid if the fluid smells burnt.
Check the transmission fluid for metal swarf. Take a sample using the dip stick.
Replace the transmission if the transmission fluid contains metal swarf.
Other information
- Transaxle oil, B5254T7, AW55-50/51SN Transaxle Oil
- Transmission oil level - checking, B5254T7, AW55-50/51SN Checking Oil Level
- Oil grade, checking, B5254T7, AW55-50/51SN Oil Grade, Checking
Select an alternative below
1. No fault detected
2. Transmission fluid replaced, the level was low or quality was poor
3. The transmission fluid contains metal swarf.
Select alternative according to above.
1 - Checking for contact resistance and oxidation
2 - Resetting adaptation and oil quality counter
3 - Replacing transmission
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Checking for contact resistance and oxidation
- Ignition off.
Check the connector for the transmission control module (TCM). Check for contact resistance. Check for oxidation.
Other information
- To access transmission connectors, see: Transmission control module (TCM) Service and Repair
- Connecting the breakout box, AW55-50/51SN Connecting Breakout Box, Transmission Control Module (TCM)
- Checking wiring and terminals Checking Wiring and Terminals
Continue - Checking the function of the transmission
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Replacing the transmission
Try a new control system. See: Control system, replacing Service and Repair.
If this does not help, replace the transmission. See:
Continue - Resetting adaptation and oil quality counter
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Checking the function of the transmission
- Test drive the car according to: Test drive schedule, description, B5254T7, AW55-50/51SN Test Drive Schedule, Description
- Check for any clear mechanical faults in the transmission.
Does the transmission have any mechanical faults?
Yes - Replacing the transmission
No - FAULT FOUND
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Replacing transmission
The previous tests indicate an internal fault in the transmission.
Replace the transmission. See: and
Continue - Resetting adaptation and oil quality counter
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Resetting adaptation and oil quality counter
Resetting adaptation
Resetting adaptation and the counter for "Transmission oil change"
Hint: The transmission has torque controlled adaptive pressure control. Pressure control means that the transmission regulates the pressure itself during each gear shift. This avoids harsh gear shifting. Each gear shift is evaluated by the transmission control module (TCM) and stored in the memory. This allows for compensation for wear and tear in the transmission and clutch. It is important that the adaptation in the memory is reset after the transmission has been repaired. This is to ensure normal operation. The oil is replaced during repair; the "Transmission oil change" counter must be reset. If the counter is not reset when the fluid is drained and replaced, there is a risk that a diagnostic trouble code (DTC) will be stored in incorrect circumstances.
Note! This applies only if the transmission or one of the components in the transmission have been replaced.
- Ignition on.
- Gear selector in position P
Click on the VCT2000 symbol to reset the adaptation and counter.
Continue - DONE
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DONE - Verification
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off
- Reinstall the components, reconnect the connectors etc.
- Ignition on.
Test drive the car according to: Test drive schedule, description, B5254T7, AW55-50/51SN Test Drive Schedule, Description
Check that the transmission does not display any obvious mechanical faults.
Note! When test driving, the oil temperature must be above 20 °C.
Was the function OK?
Yes - VERIFIED
No - VERIFICATION FAILED
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VERIFICATION FAILED - Fault-tracing information
VERIFIED - FAULT FOUND
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Fault-tracing information
Attempt New Test - Checking the oil quality and the oil level in the transmission
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