Welcome to CAN-bus

WithTony Gilroy

COURSE OBJECTIVES

Introduction to CAN-busPhysical properties of the CAN-busThe CAN-bus protocolNetwork topologyFunctional systemsDiagnosisProgramming

1. Introduction to CAN-bus

ADVANTAGES OF CAN-bus

Fewer sensors and signal wires due to multiple use of one sensor signal.Less wires in the cable harness.Considerable weight reduction in the wiring harness.Fewer plug-in terminals in the control unit connectors.Improved reliability and serviceability.Large variety of new comfort functions.

1. CAN-controller.2. CAN-transceiver.3. Microprocessor.

2. Physical properties of CAN-bus

1. Symbol for twisted wire.2. Wire colour; green and white.3. Symbol for CAN-low and CAN-high lines.

High-Speed Bus HSCAN

Mid-Speed Bus MSCAN

1.5 V2.5 VHigh & Mid Speed Can Voltage RangeCan -HighCan - Low0 V0 V2.5 V3.5 V

Low-Speed Bus LSCAN

3.9 k ohms:9.09 k ohms: 2 = CIM 1 = DIS 3 = PDM 5 = SDM 4 = SRM 6 = PAS 8 = REC 7 = TPMS10 = DDM13 = SLM12 = DSM15 = UEC14 = BCM17 = AHS16 = IPC

Low-Speed Bus LSCAN

12 Volts4 VoltsLSCAN Wake-up signal

LSCAN Scope Trace

Terminal

Signal

Terminal

Signal

1

CAN-H (LSCAN)

9

-

2

-

10

-

3

CAN-H (MSCAN)

11

CAN-L (MSCAN)

4

31, ground

12

KW 82 (Navigation, GPS unit and car phone radios)

5

31, ground

13

-

6

CAN-H (HSCAN)

14

CAN-L (HSCAN)

7

-

15

-

8

KW 2000 (Basic radios + Telematic unit)

16

30, 12V supply

3. The CAN-bus protocol

Message on its way one dominant bit a 0 ( zero )This contains message priority more 0s ( zeros ) Check field to confirm the lengthActual message2nd check fieldConformation fieldEnd of frameNot used

0= 1,5 Volt ( Low)0 = 3,5 Volt (High)Signal=Difference between CAN-high and CAN-low.Potential difference will either be 2 volts or 0 volts.1= 2,5 Volt (High)1 = 2,5 Volt ( Low)

0 = 1,5 Volts (CAN-low)0 = 3,5 Volts (CAN-high)1 = 2,5 Volts (CAN-low)1 = 2,5 Volts (CAN-high)

HSCAN & MSCAN (TWIN SCOPE)1=Dominant (0)2=Recessive (1)3.5 V2.5 V1.5 V

HSCAN & MSCAN (SINGLE SCOPE)1=Dominant (0)2=Recessive (1)3.5 V2.5 V

4. Network Topology

DIAG.HSCANCIMHSCANYRSHSCANABSHSCANEHPSHSCANAHLHSCANTCMHSCANECMHSCANHSCAN-bus120 ohm resister120 ohm resister

DIAG.HSCANCIMHSCANYRSHSCANABSHSCANEHPSHSCANAHLHSCANTCMHSCANECMHSCANHSCAN-bus

MSCAN-bus

Instrument RingBodyRingLSCAN-bus

High / Mid & Low Speed CAN-busTopology

Information flow from High to Mid speed Can-busA.B.S Speed signalNavigation systemHigh Speed BusLow Speed BusMid Speed Bus

5. Functional systems

01.02 S1Passenger compartment lampRoof lamp

01.02 S1

Door open signal

E67A162

Interior Lighting

Stop lamp switchExterior Lighting

Hazard Lighting System

Immobiliser

RC ID = OK ??Immo ID = OK ??Environment ID = OK ??BCMCIMDDM / PDM

Central Locking

Anti Theft Warning SystemREC

Window Lifters

Wiper/Wash System

CAN-Bus07/T1ASTRA-H

Bus topologyHSCAN, basic equipment07/T22

Bus topologyHSCAN option07/T23

Bus topology07/T24Engine ConnectorBody Connector

Bus topology07/T26

Bus topology07/T20

Bus topology07/T21

LSCAN-Bus TopologyRECUEC

InternallyConnectedRECPASPEPSLSCAN-Bus

LSCAN-BusRECUEC

Gateways and Diagnostics

Personalisation

Personalisation

6. Diagnosis

Error ProcessingError ActiveError PassiveBus Off

Diagnostic Trouble CodesU2100 CAN-Bus MalfunctionU2101 Maximum Configuration List Not ProgrammedU2102 More Controllers On The Bus Than Programmed/ Maximum Configuration List Not CompleteU2103 Node Error/ No Communication With CAN-Bus/ CAN-Bus OFFU2104 CAN-Bus Reset Counter OverrunU21xx Lost Communication WithU21xx Invalid Data From

Dos and Don'ts on the CAN-busWhen carrying out measurements on the CAN-bus system:Dont transfer data when using an ohmmeterDo switch off ignition and allow units to power downDo check resistance of units CAN-high in and output, CAN-low in and output should read zero ohmsDo check resistance of CAN-bus circuit both High and Mid, should read 60 ohmsDo check resistance on CAN-low but be aware of different readings for units (see table) special tool requiredDont disconnect units when there is still infodata exchange over the bus

Green flashing light

Note: F6: E.O.B.D.

F0 and F1 have been interchanged

1 System2 Main controller3 Trouble code definition4 Trouble code status

1 Control units within Body systems

7. Programming

Replacing or Exchanging Control UnitsReset the control unitDisconnect the control unitInstall the new control unitProgram the new control unit

Resetting Control UnitsTech 2Select Functional SystemSelect ProgrammingSelect Control UnitPerform Reset Function

Programming Control UnitsTech 2Select Functional SystemSelect ProgrammingSelect Control UnitPerform Program Function

Overview of control unitsStandard HSCAN CIMABSECU07/T2

UECTCMECM120 OHMRESISTORSCDCCIMDLCHSCAN Bus Topology

HSCAN Bus TopologyPRIVATE CANYRSABSEHPSTCMCDCUECAHL/AFL

With (ZF) HSCAN connection for engines of over 1.6 litres (except Z 17 DTL)

Without (TRW) HSCAN connection: System as Astra G. Diagnosis is then via diagnostic plug, pin 7Overview of control unitsEHPS - two versions07/T4

Overview of control unitsHSCAN option TCM/MTAAHL/AFLEHPSCDC07/T3

Overview of control unitsStandard MSCANTID07//T5

MSCAN-BusResistor located within DIS - 60 ohms

ECCDABEHUOverview of control units MSCAN optionBID/ GID/ CID07/T6

Overview of control unitsStandard LSCANUECRECSDMIPCCIMTID07/T7

Overview of control unitsLSCAN optionTPMSEHS/AHSPAS07/T8

VECTRA-C07/T9Light switchHazard warning switchAmbient temperature sensorBrake fluid levelBCMPDM+DDMInterior lightingEWW, rearCL, rearEWW, frontCL, frontDifferences with respect to Vectra-C

ASTRA-HDifferences with respect to Vectra-C07/T10

ASTRA-H ?? Interior lighting ???? EWW, rear ???? CL, rear ??EWW, frontCL, frontIPCUECREC07/T11Light switchHazard warning switchAmbient temperature sensorBrake fluid levelDifferences with respect to Vectra-C

ASTRA-HInterior lightingEWW, rearCL, rearEWW, frontCL, frontIPCUECREC07/T14Light switchHazard warning switchAmbient temperature sensorBrake fluid levelDifferences with respect to Vectra-C

Main functions of the REC: Window winders, central locking, alarm system

Terminal "W"

Rear lamps, interior lighting

Trailer electrics (with trailer module)

Fuel level07/T15Differences with respect to Vectra-C

Main functions of the UEC: Front lamps, rain/ light sensor Wipers, washer pumps

Coolant, brake fluid and screen washer system levels

Brake lining wear, ambient temperature

Reverse gear switch (manual transmission)

07/T16Differences with respect to Vectra-C

Main functions of the IPC: Display of road speed, engine speed, tank level

LED for coolant temperature

AT/MTA current gear display

Controls heated rear window/ heated mirror

Switch strip and light switch inputs

07/T17Differences with respect to Vectra-C

07/T18Differences with respect to Vectra-C

07/T19Differences with respect to Vectra-C

07/T27

F= 90x/ min T= 50%Activate hazard warning lightsCIMRECUECIPCCLICK CLACKLSCANLSCANHazard warning switchHard-wiredFunctional systemsHazard warning lights07/T28

Functional systemsExterior lighting07/T29

Terminal "W"Functional systems07/T30

YRSABS/ESPPrivate CANHSCANUECHSCAN with ABS and ESPBus topology07/T25