Tire Monitor System - Warning Lamp Diagnostics
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44 TPMS general diagnosis for warning on
44 10 08
2024336/1
September 20, 2010
AFFECTED VEHICLES
CONDITION
Tire pressure monitoring warning displayed in the instrument cluster.
TECHNICAL BACKGROUND
A tire pressure monitoring warning displayed in the instrument cluster does not necessarily mean that there is a fault. It could mean that the pressure
in one or more of the tires is under inflated and requires adjustment, or the proper procedure for correcting low pressure or changing wheel sets was
not followed.
This TSB contains helpful information for diagnosing BERU digital tire pressure monitoring systems installed in A8 (D3) models, which display tire
pressures and temperature in the MMI display screen.
PRODUCTION SOLUTION
SERVICE
Always explain to the customer that when TPMS warnings are displayed, it is important to first check all tire pressures and make any necessary
adjustments as soon as possible. Description of the warning and necessary corrective procedures can be found in the Owner's Manual. This is critical
in order to properly diagnose TPMS concerns.
1. Before performing any diagnosis or replacing any parts, check and verify the following points with the customer.
a. What warning was/is shown in the instrument cluster and what is shown in the MMI display after selecting Display tire pressures?
^ Checking the pressure and temperature of each tire, including the spare, in the MMI is an easy way to determine which tire might have an
issue.
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^ Tire pressures should only be set when tires are cold or are at ambient temperature. Tire pressures stored when tires are hot/warm will drop
after tires have cooled and may drop below the minimum threshold (based on the 3rd and 4th digits in the coding), which will trigger a
warning. On average, a temperature change of 10锟斤拷F results in a pressure change of 1 psi or a temperature change of 10锟斤拷C results in a pressure
change of 0.1 bar.
^ Tires on one axle (2 front wheels or 2 rear wheels) should not have more than 6psi (0.4bar) of difference in pressure.
^ If dashes are shown in place of temperatures and pressures, perform Initializing wheels procedure according to instructions in the Owner's
Manual.
b. Have any of the following been done without selecting Initialize wheels?
^ Tire pressures adjusted (up or down).
^ Wheels and tires changed (e.g. winter <--> summer).
^ New sensor(s) installed.
^ Tire rotation - system must learn new location of each sensor.
^ Spare tire was used as a result of a flat tire - system must learn new location of each sensor.
c. Is any aftermarket equipment, which operates on the same frequency of 433 MHz as the TPMS, used in the vehicle?
d. Were there any loose sensors in the vehicle or near the vehicle when Store Curr. tire pressures was selected and the required test drive was
performed? If the system sees more than 5 sensors, it will set a DTC and will not store new pressures or learn any sensors.
Proceed to steps 2 and 3 only if none of the points in step 1 resolved the concern.
2. Check fault memory and diagnose each fault according to GFF test plans. Only proceed to steps 3 and 4 if none of the previous points resolved the
concern.
3. Check control unit coding. Check the tire pressure decal on the vehicle or in the Owner's Manual for proper pressure values.
^ 1st digit: Identifies the vehicle manufacturer. Use "2" for Audi.
^ 2nd digit: Identifies the system frequency and country. Use "1" (US/CAN).
^ 3rd and 4th digits: Specified Partially Loaded Pressure. If the tire pressure is below or falls below this value, the system will not accept the Store
Curr. tire pressures command and will issue a warning. There are typically 2 pressure values shown, one for the front axle and one for the rear
axle. Always enter the smallest value of the two.
Example: XX22XX = 2.2 Bar
^ 3rd digit: Whole number position of pressure in bar
^ 4th digit: Tenths position of pressure in bar
^ 1.7 bar is the lowest acceptable partially loaded pressure.
^ 5th and 6th digits: Specified Pressure Fully Loaded. There are typically 2 pressure values shown, one for the front axle and one for the rear axle.
Always enter the smallest value of the two.
Example: XXXX27 = 2.7 Bar
^ 5th digit: Whole number position of pressure in bar
^6th digit: Tenths position of pressure in bar
4. Check sensor and battery status in MVBs 1-15.
Sensor status - MVBs 3, 6, 9, 12, 15
^ 01h: No changes in the actual pressure.
^ 02h: A pressure loss was recognized.
^ 03h: A thermal cutout occurred. This can be caused by an under-inflated tire.
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^ 04h or greater: Sensor is inoperative and must be replaced.
Battery voltage - MVBs 3, 6, 9, 12, 15
^ OK (i.O.) -is operating properly.
^ not OK (n.i.O.) -Sensor is faulty and needs to be replaced
^ No Signal (Kein Signal) - The sensor signal was (intermittently) lost.
Tip: This does not mean the sensor is faulty. Continue with bulletin.
Remaining sensor-battery life - MVBs 2, 5, 8, 11, 14
Battery service life is a theoretical value that is determined by special calculations. Difference in battery service life between sensors is not an issue
and will not trigger a warning.
Only proceed to step 5 if all previous points have been addressed.
5. Perform antenna diagnosis according to the instructions in GFF. Test each antenna individually.
Additional points and alternative repairs that may help with diagnosis:
^ Keep in mind that new sensors become operational once subjected to specified air pressure for several minutes.
^ Another way to isolate an inoperative sensor is to release 6psi (0.4bar) out of each tire while observing MVB 16. Then swap the wheel that has a
sensor status that did not change with a wheel that has a sensor status that did change to 02h. Again release 6psi (O.4bar) from specified pressure
out of these two tires and check their status. If the status still does not change on the suspected wheel, then this sensor is inoperative and must be
replaced. If the sensor status does change but now the known good sensor does not change status to 02h, then this is not due to an inoperative
sensor.
WARRANTY
This TSB is informational only and not applicable to any Audi warranty.
ADDITIONAL INFORMATION
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information.
