8/14/2019 219 HO TPC (GC_RP) 06-20-02

1/33

1

Tire Pressure Monitoring (TPC)

319 HO 10 TPC (GC,RP) 06-20-02

8/14/2019 219 HO TPC (GC_RP) 06-20-02

2/33

2

These technical training materials are current as of the date noted on the materials, and may be revised or updated without notice.

Always check for revised or updated information.

To help avoid personal injury to you or others, and to avoid damage to the vehicle on which you are working, you must always refer

to the latest Mercedes-Benz Technical Publication and follow all pertinent instructions when testing, diagnosing or making repair.Illustrations and descriptions in this training reference are based on preliminary information and may not correspond to the final US

version vehicles. Refer to the official introduction manual and WIS when available.

Copyright Mercedes-Benz USA, LLC, 2002

Reproduction by any means or by any information storage and retrieval system or translation in whole or part is not permitted

without written authorization from Mercedes-Benz USA, LLC or its successors.

Published by Mercedes-Benz USA, LLC

Printed in U. S.A.

8/14/2019 219 HO TPC (GC_RP) 06-20-02

3/33

3

General Information TPC constantly monitors tire pressure

Pressure and temperature values are sent from the wheels to antennas

using radio frequency Antennas are connected directly to TPC module

Ambient temperature and fuel level are supplied via CAN-B

TPC module evaluates data and passes it on to the instrument cluster

module (ICM) via CAN-B

ICM display informs / warns driver of:

Sudden pressure loss

Pressure too low

TPC system failure

External interference

Low battery in sensor

8/14/2019 219 HO TPC (GC_RP) 06-20-02

4/334

Advantages

Early warning when sudden pressure loss occurs

Avoid blowouts due to high speed / low pressure conditions

Driver is alerted to the need to check tire pressure

Pressure can be checked electronically

Tire wear reduced (-0.3 bar = 25% reduction in service life) Increased fuel mileage

8/14/2019 219 HO TPC (GC_RP) 06-20-02

5/335

Survey of Pressure Checking Habits% Of passenger car drivers who check tire pressure:

Weekly 8.76 % When tires seem low 25.63 %

When serviced 30.18 %

Before long trip 0.99 % Other 6.46 %

Do not check 6.56 %

In a random check of 6442 cars stopping at gas stations:

36% had one or more tires that were at least 20% under-inflated.

26% had one or more tires that were at least 25% under-inflated.

(Source: NHTSA study)

8/14/2019 219 HO TPC (GC_RP) 06-20-02

6/33

8/14/2019 219 HO TPC (GC_RP) 06-20-02

7/337

TPC Function-typical

(W220 video)

8/14/2019 219 HO TPC (GC_RP) 06-20-02

8/338

Electronic Tire Pressure Check

Electronic check:

1. Call up the odometer display bypressing steering wheel buttons

(2)

2. Display tire pressure by pressing

steering wheel arrow buttons

(v)

Four values are displayed

In either barorpsi

Blanks indicate that no values

are stored

This is also the display youll see

after performing an activation to

store new pressure values

8/14/2019 219 HO TPC (GC_RP) 06-20-02

9/339

Basic TPC Components

4 wheel sensors:

- Pressure

- Temperature

4 Antennas in

wheel housings

TPC module

CAN-B

Instrument Cluster

Module

- Readout values

- Display warnings- Vehicle speed

input

8/14/2019 219 HO TPC (GC_RP) 06-20-02

10/3310

Wheel Sensors and Antennas

Transmission intervals

New sensor inoperative until 1.5 bar applied for > 3 minutes

Normal conditions: Measure once every 3 seconds, transmit once every 55 seconds

When pressure drops >0.2 bar / minute: Measure and transmit once every 0.8 second

8/14/2019 219 HO TPC (GC_RP) 06-20-02

11/33

8/14/2019 219 HO TPC (GC_RP) 06-20-02

12/3312

Wheel Sensor Battery

Battery not replaceable

Battery life approximately 7

years

With each data transmission,

the sensor reports on remaining

battery life

DAS can be used to check

remaining battery life (inmonths)

Production date (july 15,1999)

stamped on sensor

8/14/2019 219 HO TPC (GC_RP) 06-20-02

13/33

13

W211 TPC Module (N88)

At left side of trunk,

behind rear SAM

Task: Receive tire pressure and temperature info from wheel sensors.

Process info received via CAN-B and determine if tire pressures are OK.

T.30 Power and ground supplied by N10/2

8/14/2019 219 HO TPC (GC_RP) 06-20-02

14/33

14

Additional Inputs to TPC

Front left SAM

- Ambient temp

- Charging volts

Rear SAM

- Fuel level

- Trunk lid status

Central gateway

- Country

- Vehicle specific info

EIS

- Ignition on

CAN-B

8/14/2019 219 HO TPC (GC_RP) 06-20-02

15/33

15

Tire Service Stay clear of wheel sensor to

prevent damage

With tire removed, checkcondition of wheel sensor - no

need to remove sensor from

wheel to do this!

Before mounting tire, checkdate stamp on sensor

Replace sensor if over 5 years

old

43a Wheel weight43g Wheel sensor (~32 grams)

8/14/2019 219 HO TPC (GC_RP) 06-20-02

16/33

16

Wheel Sensor Inspection White filter on underside of sensor

Dont remove it

No compressed air or detergents

Use a clean, lint-free cloth

Replace entire sensorif:

Damaged

Too dirty to clean

Tire sealant was used

Over 5 years old

Replace valve if: It has been removed

Screw or nut is loose

8/14/2019 219 HO TPC (GC_RP) 06-20-02

17/33

17

Installing Wheel Sensor Always use new valve

315mhz must show on U.S. Sensor

Record electronic ID number of sensor

2.0mm hole in valve must face upward

Spacer has 45 bevel on both sides

When installing new sensor, use 2.0mm

pin (6) to counter hold valve (2) while

tightening lock nut (4)

Hollow screw and nut both torqued to

4nm

Electronic ID number

24

8/14/2019 219 HO TPC (GC_RP) 06-20-02

18/33

18

Electronic Identification Number

Each sensor has a unique, wheel

electronic identification number thatit sends to the TPC module with

each data transmission

The TPC module must learn thisnumber and identify it with a specific

wheel position on the vehicle

The wheel electronic identification

number is stamped on the sensor

433MHz indicates European standard (US version = 315MHz)

8/14/2019 219 HO TPC (GC_RP) 06-20-02

19/33

19

Activation NotesActivation means: Clearing old tire pressure specifications from TPC memory

Storing new tire pressure specification values for each wheel

Activation is performed when:

Setting a different inflation pressure base-line value

Cluster says to re-activate TPC

Tires are rotated

Winter tires are mounted

A wheel sensor has been replaced

The TPC control module has been replaced A TPC fault code has been erased

Activation isinitiated using steering wheel & ICM buttons and completed by driving

the vehicle

8/14/2019 219 HO TPC (GC_RP) 06-20-02

20/33

20

Learning Wheel Sensor Location

Before new tire pressure specification values can be stored, the TPC module

must have learned the wheel sensor identification numbers and matched

those numbers with their specific location on the vehicle

The fastest way for the TPC module to learn this information is by entering it

into TPC memory using the DAS program. (Control unit adaptations >

settings)

Activation will occur faster if sensor locations are already known

The slower method of learning is to simply perform an activation. While

driving, first the wheel sensor locations will be learned and then the new

pressure specifications will be stored

TPC will have to determine sensor location by measuring field strength at

the antennas

TPC must receive a greater number of clear signals from each sensor

8/14/2019 219 HO TPC (GC_RP) 06-20-02

21/33

21

TPC Activation Procedure

1. Vehicle stationary

2. Tire pressures set correctly

3. Engine OFF / Ignition ON4. Use steering wheel buttons (2) to scroll

to 0 mph display (S110s1)

8/14/2019 219 HO TPC (GC_RP) 06-20-02

22/33

22

TPC Activation Procedure5. Use steering wheel buttons (/)

to display tire pressure screen

6. Tap the reset button (A1r1)

8/14/2019 219 HO TPC (GC_RP) 06-20-02

23/33

23

TPC Activation Procedure

7. Press the + button (S111s1) on steering wheel to bring up the next display...

This will be the next screen:

8/14/2019 219 HO TPC (GC_RP) 06-20-02

24/33

24

Activation now begins

TPC Activation Procedure

This screen indicates that previous

settings have been cleared

8/14/2019 219 HO TPC (GC_RP) 06-20-02

25/33

25

After driving 10-30 minutes, display will suddenly show four actual

pressures. (Remember: 1 signal every 55 seconds)

System is then activated, with new values stored

If the values you are trying to set are implausible, cluster will display:

tire pressure / check tiretire pressure / check tire

TPC Activation Completed

8/14/2019 219 HO TPC (GC_RP) 06-20-02

26/33

26

TPC Messages Are Displayed in ICM

Example shown: system

shut-down due to

outside interference

Function or operation

warnings are

displayed in white

Red warning display =

major loss of

pressure

8/14/2019 219 HO TPC (GC_RP) 06-20-02

27/33

27

Function Warnings

Tire pressure monitor / Visit workshopTire pressure monitor / Visit workshop

CAN, component, sensor battery, DTC is stored

Tire pressure monitor temporarily inactiveTire pressure monitor temporarily inactive

During initialization, external interference, temp. >120C, additional

wheel sensors in vehicle

Tire pressure monitor activatedTire pressure monitor activated

During activation - pressures show after driving a few minutes

Tire pressure monitor / ReactivateTire pressure monitor / Reactivate

Pressure is 0.3 barabove stored value, or after replacing N88

8/14/2019 219 HO TPC (GC_RP) 06-20-02

28/33

28

Operation Warnings

Tire pressure / check tireTire pressure / check tire

- Pressure in one or more tires dropped >0.2 bar (2.9 psi) below storedpressure. Message shows for 30 sec. After every start-up

- Pressure difference >0.4 bar (5.8 psi) between tires on same axle

- Pressures too low, temperature OK (

8/14/2019 219 HO TPC (GC_RP) 06-20-02

29/33

29

Tire pressure LF / check tireTire pressure LF / check tire Pressure in one or more tires has dropped to 0.4 bar (5.8 psi) below the

stored pressure

Specific tire may not be indicated

Message displayed continuously

Operation Warnings Displayed in RED

Tire Pressure LF / Caution Tire DefectTire Pressure LF / Caution Tire Defect- Pressure loss >0.2 bar (2.9 psi) per minute

- Specific tire location indicated

- Stop immediately and install spare wheel / tire

8/14/2019 219 HO TPC (GC_RP) 06-20-02

30/33

30

Service Tips

When an antenna or sensor problem is suspected, remount wheel to different

location, erase DTC and see if problem moves. This will eliminate antenna, wiring,

ECU, etc. Initializing first will make this faster.

When using wheels without pressure sensors, deactivate TPC using DAS (control

unit adaptations > read coding and change if necessary > monitoring function >

F2 > select not active, then transfer coding into control unit.)

When TPC is deactivated, client will get a white message, tire pressure control-

reactivateeach time engine is started.

8/14/2019 219 HO TPC (GC_RP) 06-20-02

31/33

31

Acronyms used in this PresentationCAN Controller Area Network

DAS Diagnostic Assistance System

DTC Diagnostic Trouble Code

ECU Electronic Control Unit

EIS Electronic Ignition Switch

ICM Instrument Cluster Module

ID Identificationmph mils per hour

MHz Megahertz

NHTSA National Highway Transportation System Administration

PDI Pre-delivery Inspection

psi pounds per square inch

SAM Signal Acquisition Module

TPC Tire Pressure MonitoringVSS Vehicle Speed Signal

Ti P M it i (TPC)

8/14/2019 219 HO TPC (GC_RP) 06-20-02

32/33

32

Tire Pressure Monitoring (TPC)

Group: 40.15

Control unit designation: N88

U.S. Introduction: MY2001

Major components: TPC module (N88)

Wheel sensors (A69/1-4)

Antennas (A2/44-47)

Related control modules: Driver-side SAM (N10/1)

Rear SAM (N10/2)

Central gateway (N93)EIS (N73)

Instrument cluster (A1)

CAN(s) used: CAN-B

Mils: noWarning messages in ICM? Yes

DTC capable? Yes

Control unit adaptation? Activation with driver controls

Requires control unit adaptation in: ICM

8/14/2019 219 HO TPC (GC_RP) 06-20-02

33/33

33

Appendix

W211 Self-study material

Parts listed in group 54, electronic parts catalog RDK is the German acronym

MBUSA Technical Training website:

http://www.mbusatechtraining.com/home.asp > Information Access

Web site http://www-nrd.nhtsa.dot.gov/vrtc/ca/tpms.htm contains astudy of 10 monitoring systems. System E (the Beru system on a

BMW) is the one most like the MB system.

Another interesting article on the need for tire pressure monitoring:

http://www.nhtsa.gov/cars/rules/rulings/TirePressure/fedreg.htm The first part of the NTHSA ruling on TPM:

http://www.nhtsa.dot.gov/cars/rules/rulings/TirePresFinal/Index.html