Incorrect Gear Ratio
Incorrect gear ratio
Checking for contact resistance and oxidation
- Ignition off
- Check the transmission control module (TCM), transmission output speed sensor and transmission connectors. Check for contact resistance and oxidation according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Test drive the car according to Test drive schedule, description, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Test Drive Schedule, Description.
When test driving, the oil temperature must be above 20°C. Check for transmission malfunction. Listen for mechanical noise from the transmission.
Is the function of the transmission OK?
Yes - Checking the oil quality and the oil level in the transmission
No - Replacing the transmission
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Checking the oil quality and the oil level in the transmission
Note! Transmission fluid quality and level are extremely important for transmission function. 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 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:
- To replace the transmission fluid, see Transmission fluid, replacing Transmission Fluid, Replacing
- To check the level, see Oil level, checking Checking Oil Level
- To check the quality of the transmission fluid, see Oil grade, checking, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD 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.
1 - Checking the adjustment of the gear-shift position sensor
2 - Resetting the oil quality counter
3 - Replacing the transmission
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Checking the adjustment of the gear-shift position sensor
- Ignition on
- Read off the position of the gear-shift position sensor.
Move the gear selector around the different gear positions a number of times. Check that the gear position is updated. The selected position must be the same as that displayed in VIDA. If the display shows an undefined position (OR for example) the transmission cable needs adjusting.
Note! An undefined position may be displayed between the fixed gear positions. This is not a fault.
Remedy as necessary.
Other information
- To adjust the gear-shift position sensor, see Gear-shift position sensor, checking/adjusting, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Adjustments.
Is the gear-shift position sensor incorrectly adjusted?
Yes - Verification
No - Checking the transmission output speed sensor signal
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Resetting the oil quality counter
Resetting Transmission fluid change counter
Resetting Transmission fluid change counter
Hint: The transmission control module (TCM) has a counter for the oil quality. The counter counts up if the transmission is exposed to too high a load or an ambient temperature that is too high. If the counter is not reset when the oil is drained or changed, there is a risk that a diagnostic trouble code (DTC) will be stored in faulty circumstances. Therefore it is important that the "Transmission oil change" counter is reset.
Note! This applies only when the transmission fluid is changed and when the fluid is changed when repairs are carried out to the transmission temperature sensor.
- Ignition on.
Reset the counter by clicking on the VCT 2000 symbol.
Continue - DONE
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DONE - Verification
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Checking the transmission output speed sensor signal
- Ignition off
- Raise the car so that the drive wheels can rotate freely
- Start the engine and let it run at idle speed
- Gear selector in position D
- Read off the transmission output speed signal.
Check that the speed increases with engine speed (RPM).
Note! A diagnostic trouble code (DTC) may be stored in the ABS system when the rear wheels are stationary and the front wheels rotate. Erase any diagnostic trouble codes (DTCs) in the ABS system after completing fault-tracing.
Other information:
- To disconnect the transmission control module (TCM), see Transmission control module (TCM), replacing, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Service and Repair
- To disconnect the transmission connector, see Connectors, transmission, disconnecting / connecting, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Procedures
- For information about signals, see Signal description. Transmission control module (TCM), AW50/51 AWD, AW55-50/51SN Signal Description. Transmission Control Module (TCM).
Does the speed increase with engine speed (RPM)?
Yes - Checking the transmission input speed sensor signal
No - Checking wiring and sensors
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Checking wiring and sensors
- Ignition off
- Connect the breakout box.
Check the power supply cable between transmission output speed sensor connector terminal #A4 (control module side) and control module terminal #A57 (#A57). Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the signal cable between transmission output speed sensor connector terminal #A3 (control module side) and control module terminal #A39 (#A39). Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Hint: With the control module connected, the transmission output speed sensor disconnected and the ignition on, the voltage between transmission output speed sensor connector terminals #A3 and #A4 must be approximately 1-3 V below Ubat.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box, B5244T5, B5254T2 Connecting the Breakout Box
- To disconnect the transmission connector, see Connectors, transmission, disconnecting / connecting, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Procedures
- To check or replace the transmission output speed sensor, see Replacing the transmission input speed sensor and the transmission output speed sensor Input Speed Sensor/Output Speed Sensor, Replacing
- For information about signals, see Signal description. Transmission control module (TCM), AW50/51 AWD, AW55-50/51SN Signal Description. Transmission Control Module (TCM).
Continue - Verification
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Checking the transmission input speed sensor signal
- Ignition off
- Gear selector in position P
- Start the engine and let it run at idle speed
- Read off the transmission input speed.
Check that the transmission input speed is updated.
Compare with the engine speed (RPM).
Other information:
- To disconnect the transmission control module (TCM), see Transmission control module (TCM), replacing, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Service and Repair
- To disconnect the transmission connector, see Connectors, transmission, disconnecting / connecting, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Procedures
- For information about signals, see Signal description. Transmission control module (TCM), AW50/51 AWD, AW55-50/51SN Signal Description. Transmission Control Module (TCM).
Does the transmission input speed increase with engine speed (RPM)?
Yes - Test driving the transmission
No - Checking wiring and sensors
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Checking wiring and sensors
- Ignition off
- Connect the breakout box.
Check the power supply cable for the transmission input speed sensor between control module terminal #A59 (#A59) and transmission connector terminal #A2. Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Check the signal cable between control module terminal #A41 (#A41) and transmission connector terminal #A1. Check for an open-circuit according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to ground according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault. Check for a short-circuit to supply voltage according to Checking wiring and terminals. Permanent fault Checking Wiring and Terminals. Permanent Fault.
Hint: With the control module connected and the ignition on, the voltage between transmission output speed sensor connector terminals #1 and #2 should be 1-3 V below Ubat.
Remedy as necessary.
Other information:
- To connect the breakout box, see Connecting the breakout box, B5244T5, B5254T2 Connecting the Breakout Box
- To disconnect the transmission connector, see Connectors, transmission, disconnecting / connecting, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Procedures
- To replace the transmission input speed sensor, see Replacing the transmission input speed sensor and the transmission output speed sensor Input Speed Sensor/Output Speed Sensor, Replacing
- For information about signals, see Signal description. Transmission control module (TCM), AW50/51 AWD, AW55-50/51SN Signal Description. Transmission Control Module (TCM).
Continue - Verification
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Replacing the transmission
- Fault-tracing indicates an internal fault in the transmission. Replace the transmission according to Transmission, removing Transmission, Removing and Transmission, installation Transmission, Installation.
Continue - Verification
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Test driving the transmission
Test drive the car according to Test drive schedule, description, B5244T5, AW55-50/51SN, B5254T2, AW55-50/51SN, B5254T2, AW50/51 AWD Test Drive Schedule, Description. When test driving, the oil temperature must be above 20°C.
Look out for any transmission malfunction.
Is the transmission operating correctly?
Yes - Fault-tracing information
No - Replacing the transmission control system
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Replacing the transmission control system
The previous tests indicate that there is a fault in the transmission control system.
Try a new control system according to Cable harness/oil temperature sensor, replacing Removal and Replacement.
Select "Continue" when the fault has been remedied.
Continue - Resetting the adaptation and oil quality counter
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Resetting the adaptation and oil quality counter
Resetting the 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 control module 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.
Click on the VCT2000 symbol to reset the adaptation and counter.
Continue - DONE
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DONE - Verification
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Fault-tracing information
The control module has previously registered a fault. The fault is now no longer present. A test of the transmission function indicates that everything is now OK.
Continue - No Fault Found
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Verification
Verification
Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off
- Reconnect the connectors, components, etc.
- Ignition on
Test drive the vehicle following: Test drive schedule, description Test Drive Schedule, Description
During the test drive, oil temperature should be over 20 °C.
Note any deviations in transmission function.
Does the transmission function flawlessly?
Yes - VERIFIED
No - VERIFICATION FAILEDPAPER
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VERIFIED - Fault Found
VERIFICATION FAILED - Checking for contact resistance and oxidation
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