Parking Aid, Spa: Other Saab 9-3 II

To fit

Scheme 24

Scheme 25

1. Plug in the control module connector.
2. Press the SPA module onto the main fuse box.
3. Replace the carpet.
4. Fit the clips securing the luggage compartment carpet.
5. Close the left-hand hatch in the luggage compartment.

Carry out PROCEDURE AFTER CHANGING THE CONTROL MODULE .

Refitting

Scheme 26

1. Plug in the control module connector.
2. Press the control module onto the main fuse box.
3. Fit «LUGGAGE COMPARTMENT TRIM, CV»(ref-275837-S20608773682007122900000) .
4. Carry out «PROCEDURE AFTER CHANGING THE CONTROL MODULE»(ref-275867-S39583780392007122900000) .

Scheme 27

Scheme 28

1. Remove «BUMPER SHELL, REAR, 4D»(ref-275838-S40898362652007122900000)
2. Detach the cellular plastic block from the lugs on the bumper shell.
3. Detach the sensor from the bumper shell by pressing out the locking tabs.
4. Unplug the sensor connector.
5. Remove the sensor seal.

Scheme 29

1. Fit the sensor seal.
2. Plug in the sensor connector.
3. Fit the sensor to the bumper shell.
4. Fit the cellular plastic block by feeding it in towards the bumper lugs. Press on the block.
5. Fit «BUMPER SHELL, REAR, 4D»(ref-275838-S40898362652007122900000) .

Scheme 30

1. Remove the sensor. See «TO REMOVE»(ref-275867-S01438079682007122900000)
2. Press out the decor strip locking tabs and remove the holders.
3. Fit the new holder to the decor strip. NOTE: The holder must be fitted with the wide locking tab down.
4. Fit the sensor. See «TO FIT»(ref-275867-S26066763952007122900000)

Scheme 31

Scheme 32

1. Remove Bumper shell, rear, 5D.
2. Remove the cellular block from the bumper shell.
3. Detach the sensor from the bumper shell by pressing out the locking tabs.
4. Unplug the sensor connector.
5. Remove the sensor seal.

Scheme 33

1. Fit the sensor seal.
2. Plug in the sensor connector.
3. Fit the sensor to the bumper shell.
4. Fit the cellular block by guiding it in towards the bumper shell. Press on the block.
5. Fit Bumper shell, rear, 5D.

Scheme 34

1. Remove the sensor.
2. Press out the decor strip locking tabs and remove the holders.
3. Fit the new holder to the decor strip. NOTE: The holder must be fitted with the wide locking tab down.
4. Fit the sensor.

Scheme 35

Scheme 36

1. SPA control module (630)
2. Ultrasound distance sensor, outer right (631RR)
3. Ultrasound distance sensor, center right (631RRC)
4. Ultrasound distance sensor, center left (631RLC)
5. Ultrasound distance sensor, outer left (631RL)
6. Main fuse box, engine bay, UEC (342)
7. TCM control module (502)
8. SID (541)
9. Rear electrical center, REC (701)
10. Engine Control Module (ECM)
11. BCM control module (707)
12. Infotainment control panel, ICM (736)
13. SID control panel, SIDC (737)
14. Entertainment head unit, EHU (353)

Control Module Use

The control module is used to

1. calculate the distance to the closest object behind the vehicle using the values obtained from the distance sensors.
2. indicate the distance to the closest object behind the vehicle to the driver by means of audible signals via the loudspeakers in the audio system
3. determine when measurement should take place.
4. check and control the distance sensors.
5. communicate and collect information from other systems in the vehicle via the I-bus.
6. supply current to the rear distance sensors.
7. ground the rear distance sensors.
8. check the function with continuous self diagnosis.
9. communicate with the diagnostic tool.

Scheme 37

Parking assistance can be temporarily switched off, for example when using a trailer without electrical connection. This is done by pressing the CLEAR button on SIDC (SID control panel) when parking assistance is active.

There are two alternative methods of re-engaging the parking assistance

1. Ignition OFF followed by ignition ON.
2. Disengage and engage reverse gear.

Scheme 38

Parking assistance can be discontinued from Customer Settings.

1. Go to «CUSTOMER SETTINGS»(ref-275866-S41496236762007122900000) by pressing the CUSTOMIZE button on SIDC.
2. Select "Park Assistance" with the INFO knob.
3. Press the INFO knob.
4. Select "SPA off".
5. Confirm the choice by pressing the INFO knob.

To engage parking assistance again, select "SPA on" from the "Park Assistance" menu.

Text Messages

Text messages are stored in different languages in ICM (infotainment control panel) and is sent via two communication cables to SID, where they are displayed.

The following text messages are stored

1. Parking assistance active.
2. Parking assistance off.
3. Parking assistance malfunction. Contact service.
4. Parking assistance sensor interference.

Scheme 39

The four distance sensors use ultrasound to measure the distance to the object behind the car. They are located in the rear bumper and are named as follows

1. Left outer distance sensor (RL)
2. Left center distance sensor (RLC)
3. Right center distance sensor (RRC)
4. Right outer distance sensor (RR)

The control module receives information from the underhood electrical center, UEC (manual transmission) or TCM (automatic transmission) via a bus message when reverse gear is selected, and the control module then activates the distance sensors. These sensors begin to transmit and receive audible signals according to a loop controlled by the control module which is repeated 3 times a second.

Each distance sensor contains a piezo-electric element that acts as both a speaker element and a microphone element.

The distance sensors transmit wide angle ultrasound (120° horizontal and 60° vertical) and receive reflected acoustic signals. These signals are converted to digital signals that are conveyed to the control module for calculation of the distance to the closest object.

Scheme 40

When calculating the distance, the control module takes information from the distance sensors (within 180 cm behind and 50 cm to the side), vehicle speed (below 14 km/h) and outside temperature.

Continuous information from the sensors concerning the closest object is processed by the control module so that the correct value can be sent to the I-bus. The audio system uses the information for indicating to the driver.

The driver receives information concerning the closest object behind the vehicle in the form of a varying number of tones from the audio system. The first tone is given when the object is 1.8 meters behind the vehicle and has a frequency of 2 tones per second.

The closer the vehicle comes to the object, the closer together the signals, until the car is 30 cm or less from the object, when the signal is continuous. The signal changes as follows

1. 1.8 - 1.3 m: 2 tones/second
2. 1.3 - 1.0 m: 3 tones/second
3. 1.0 - 0.8 m: 6 tones/second
4. 0.8 - 0.3 m: from 10 to 50 tones/second in close steps
5. 0.3 - 0 m: steady tone

The distance sensors work in a loop pattern (controlled by the control module) that is repeated 3 times per second. The loop has the following pattern

Scheme 41

Scheme 42

1. Step 1: Sensor - RL - sends acoustic signals and listens with sensors 1 and 2.
2. Step 2: Sensor 2 - RLC - sends acoustic signals and listens with sensors 1 and 2.
3. Step 3: Sensor 2 - RLC - sends acoustic signals and listens with sensors 2 and 3.
4. Step 4: Sensor 3 - RRC - sends acoustic signals and listens with sensors 2 and 3.
5. Step 5: Sensor 3 - RRC - sends acoustic signals and listens with sensors 3 and 4.
6. Step 6: Sensor 4 - RR - sends acoustic signals and listens with sensors 3 and 4.

When this loop is complete, the control module will determine the closest object behind or beside the vehicle, i.e. the object for which the driver should be warned, using Pythagoras' theorem (a 2 +b 2 =c 2 ).

If the driver reverses at a speed in excess of 1.8 m/s (6.5 km/h), parking assistance (SPA) is of no use as the distance indication is limited to 1.8 m behind the car. At this speed, the driver would have 1 second in which to react and stop the vehicle. The braking distance also has to be taken into account. The car must be travelling at a moderate speed in order to use parking assistance.

If the distance sensors are covered with ice, snow or dirt, their operation will be impaired. The distance sensors should be wiped clean.

If the car is reversing on a surface that reflects a lot of ultrasound back to the car sensors, the system may indicate the distance to the ground instead of an object behind the car. This can happen e.g. on a gravel road or other uneven surface. Functional tests should be performed on flat ground without ground based objects.

Side objects

Parking assistance can also allow for objects located at the side of the car, e.g. while reversing adjacent to a garage wall. In this case, if any of the outer distance sensors detect an object that adjacent sensors have not detected then the object will be indicated as a side object. The limit for detecting side objects is approx. 50 cm.

If the object located at the side of the car remains at a constant distance for more than 3 seconds, indication stops. Instead, the next nearest object will be signalled to the driver. If the object located at the side of the car approaches by 5 cm (2 inches), the control module will once again indicate this object to the driver via the audio system.

Towbar

The system is automatically switched off when a trailer or caravan is hooked up to the car. The system will adapt instantly if a rear hitch is fitted. This information is transmitted on the I-bus by the rear electrical center, REC (701).

Control module

The control module is programmed to suit all car variants. It is connected to the bus and communicates with ICM for distance indication and text messages, and to the diagnostic tool for diagnostic communication. After changing the control module, all the necessary information from associated control modules is retrieved on the bus.

Mode

The control module has four modes. The distance sensors are active in modes 2 (Measuring) and 3 (Presentation).

The four modes are

1. Mode 1, Standby - the control module is in standby mode and awaiting information on the bus. If reverse is engaged then the control module will switch to mode 2.
2. Mode 2, Measuring - the control module (and the sensors) is measuring within a range of 180 cm and cannot detect an object.
3. Mode 3, Presentation - the control module is measuring within a range of 180 cm and indicates an object with an acoustic signal on the speakers.
4. Mode 4, Off - the control module is turned off temporarily via SIDC with the CLEAR button or permanently with the CUSTOMIZE button.

The control module activates the sensors in mode 2 (Measuring) first with power supply, ground and bus communication.

Parking Assistance (SPA), Bus Information

For a detailed description of the car's bus system, see DETAILED DESCRIPTION .

BUS INFORMATION

Principal use

This control module calculates the distance to the closest object behind the vehicle based on the values given by the distance sensors. The distance is indicated to the closest object by acoustic signals on the speakers.

Type

The control module consists of a microprocessor with a clock, RAM and I/O unit. An internal bus links the processor and memory to the I/O unit. The I/O unit is responsible for reading values from A/D converters for digital inputs and bus and for activating the transistors in the final stages; see CONTROL MODULES, GENERAL DESCRIPTION . The distance sensors communicate via a two-way communication bus between the sensors and the control module.

Power Supply, Ground and Bus Communication

PIN OUTS REFERENCE

Scheme 43

Scheme 44

Scheme 45

Ultrasound distance sensor, outer left (631RL)

Ultrasound distance sensor, center left (631RLC)

Ultrasound distance sensor, center right (631RRC)

Ultrasound distance sensor, outer right (631RR)

The four distance sensors use ultrasound to measure the distance to the object behind the car. They transmit wide angle ultrasound (120° horizontal and 60° vertical) and receive reflected acoustic signals. These signals are converted to digital signals that are conveyed to the control module for calculation of the distance to the closest object.

Each distance sensor contains a piezo-electric element with a communication unit. The piezo-electric element acts as both a speaker element and a microphone element. The sensor has a plastic housing and is connected with three wires. The sensor is located in a holder and fastened with two clips. The holder is fastened in the center decor strip on the rear bumper. The distance sensors are identical and interchangeable.

Scheme 46

Scheme 47

Scheme 48

Scheme 49

Scheme 50

Ultrasound distance sensor, outer left (631RL)

PIN OUTS REFERENCE

Ultrasound distance sensor, center left (631RLC)

PIN OUTS REFERENCE

Ultrasound distance sensor, center right (631RRC)

PIN OUTS REFERENCE

Ultrasound distance sensor, outer right (631RR)

PIN OUTS REFERENCE

SID (541)

Location: at the top of the instrument panel

Scheme 51

4D

Location: In luggage compartment behind backrest member on left-hand side.

K12

Scheme 52

K18

Scheme 53

5D

Location: on side of rear electrical center

K12

Scheme 54

K18

Scheme 55

CV

Location: under Rear Electrical Center

K12

Scheme 56

K18

Scheme 57

Ultrasound Distance Sensor, Outer Left (631RL)

Location: On left-hand side of rear bumper.

Scheme 58

Ultrasound Distance Sensor, Center Left (631RLC)

Location: On left-hand side of rear bumper.

Scheme 59

Ultrasound Distance Sensor, Outer Right (631RR)

Location: On right-hand side of rear bumper.

Scheme 60

Ultrasound Distance Sensor, Center Right (631RRC)

Location: On right-hand side of rear bumper.

Scheme 61

Main task

Act as the electrical center for the rear of the car and the roof, and perform certain logic functions such as for the rear lighting.

Electrical center with relays, Maxi and micro fuses and an integrated control module for logic functions. Wiring for a trailer connector is connected to the electrical center.

Scheme 62

Connect

The electrical center is fed with a +30 supply from the engine bay electrical center (342) and grounded to grounding points G3 and G29. The electrical center is connected to the wiring harness via 7 connectors

Scheme 63

Scheme 64

Scheme 65

Scheme 66

Scheme 67

Scheme 68

Scheme 69

Scheme 70

Scheme 71

Scheme 72

Scheme 73

Scheme 74

1. Body 1 (in diagram = B1) to main wiring harness
2. Body 2 (in diagram = B2) to main wiring harness
3. Body 3 (in diagram = B3) to main wiring harness
4. Head 1 (in diagram = H1) 4D to roof harness 5D to roof harness
5. Head 2 (in diagram = H2) 4D to roof harness 5D to roof harness CV to main wiring harness
6. Rear (in diagram = R) to rear wiring harness
7. Tail (in diagram - T) to: 4D: parcel shelf harness 5D: rear harness CV: rear harness

The connectors for the main, parcel shelf and rear wiring harnesses each comprise four connectors, which are named A, B, C and D in the wiring diagrams, for example B1-B.

The TR-WH connector is used for a trailer connector. In some cases a special module, TR-MOD, is required.

The electrical center contains the following power circuits

+30 power supply, rear electrical center. See POWER DISTRIBUTION .

+15 power supply, rear electrical center. See POWER DISTRIBUTION .

Fuses

The electrical center can contain a greater number of fuses than those listed below. In such cases, these are not connected to a wiring harness.

FUSES DESCRIPTION

Scheme 75

The electrical center can contain a greater number of relays than those listed below. In such cases, these are not connected to a wiring harness.

RELAYS DESCRIPTION Location No Description Graphic Diagram R1 446 Electrically adjustable seat relay ELECTRICALLY ADJUSTABLE SEAT 4D/5D LH ELECTRICALLY ADJUSTABLE SEAT 4D/5D RH R2 757R Relay, +15, REC See POWER DISTRIBUTION R3 - - - - R4 113 Electrically heated rear window relay HEATING, REAR WINDOW R5 83a Rear window wiper relay REAR WINDOW WIPER 5D R6 - - - - R7 710 Boot lid opening motor relay ELECTRIC OPENING OF BOOT LID LOCK 4D R8 - - - - R9 - - - - R10 - - - - R11

Scheme 76

Scheme 77

Scheme 78

Scheme 79

Scheme 80

Scheme 81

List of Components

COMPONENTS LIST

Connector H8-5

Location: Below rear left light cluster.

Scheme 82

COMPONENTS LIST

COMPONENTS LIST

COMPONENTS LIST

COMPONENTS LIST

Scheme 83

Location: In boot below left light cluster

The grounding point is connected with grounding point G29 via the boot electrical center 701.

Connected Components

CONNECTED COMPONENTS

Scheme 84

Scheme 85

Location: In luggage compartment on rear left luggage compartment floor support.

The grounding point is connected with grounding point G29 via the boot electrical center 701.

CONNECTED COMPONENTS

Scheme 86

Scheme 87

Location: In luggage compartment below left light cluster

CONNECTED COMPONENTS

Scheme 88

Distance Sensor

DISTANCE SENSOR SPECIFICATION

SPA Module

SPA MODULE SPECIFICATION

Scheme 89

Scheme 90

The following contains readings and instructions for measuring signals and levels for SPA (Saab Parking Assistance).

Remember

1. Note the test conditions and use common sense when assessing the test result.
2. The specified readings are with the ignition ON unless stated otherwise.
3. First check that the control module has a power supply and is grounded.
4. Then check all sensor inputs and signals from other systems.
5. Finally, check the control module outputs. Remember that these readings are not an indication that the actuator is in working order.
6. If a reading is not OK, consult the wiring diagram to trace the leads, connectors or components which should be checked more thoroughly.
7. Specified values concern a calibrated Fluke 88/97.
8. Readings % (+) and ms (+) indicate the signal pulse ratio and pulse width respectively. A test instrument with pulse ratio and pulse width measurement must be used. The sign indicates a positive trigger pulse, TRIG+.

Scheme 91

PIN OUTS REFERENCE

Scheme 92

PIN OUTS REFERENCE

Scheme 93

SPECIAL TOOL COMPATIBILITY DESCRIPTION

Scheme 94

A suitable instrument to use is a multimeter.

The ohmmeter must not be used to test components containing semi-conductors, e.g. control modules and relay with timing functions, etc.

When measuring resistance, the power supply to the system being tested must be disconnected as the measuring instrument generates a weak current in the circuit in question.

This is done to ensure that there is no current already in the tested circuit and that the correct reading is obtained.

Scheme 95

Scheme 96

1. Turn on the load.
2. Set the multimeter for measuring voltage and connect the negative lead of the voltmeter to a good grounding point.
3. Connect the positive lead of the voltmeter to the point where the voltage is to be read.
4. On the output side of switches/control modules, it is better to start checking from these and gradually work your way towards the load. When there is no longer a voltage reading, you will have gone past the break point.
5. On the input side of switches/control modules/consumers, it is better to start at the power source (normally a fuse) and then move gradually towards the switch/control module/consumer. When there is no longer a voltage reading, you will have gone past the break point.

Scheme 97

Scheme 98

1. Make sure the component or lead to be tested is not under tension (e.g. by removing the relevant fuse).
2. Set the multimeter for measuring ohms and connect the ohmmeter to each end of the component/lead to be tested.
3. Jiggle the relevant wiring harness while observing the ohmmeter. Normally, the resistance of a wiring harness is less than 1 ohm. Specified values apply to components.

Scheme 99

Scheme 100

1. Make sure the lead being tested is not under tension (e.g. remove the relevant fuse) and that any loads are disconnected.
2. Set the multimeter for measuring ohms.
3. Connect one test lead to a good ground and the other to the point to be tested.
4. Carefully jiggle the wiring harness and make sure the multimeter reading shows infinite resistance (OL) all the time.

General

The demands on the car's functionality have developed strongly during the last years. Development has primarily affected the car's electrical system. From Saab 900 1994 when the instrument bus with 4 control modules via Saab 9-5 and 9-3 with the Infotainment bus and the Power train bus and 13 control modules on to the Saab 9-3 Sport Saloon with at most 30 control modules.

In addition to the I-bus and the P-bus, an Optical bus was introduced on the Saab 9-3 Sport Saloon, which interconnects the car's infotainment system. Furthermore, an electrically controlled steering column lock was introduced. Initially it will be possible to SPS program 8 of the car's control modules. Most of the car's control modules have a flash memory and will be successively included in SPS. A new function in TIS 2000 allows you to access new SPS files via the Internet between CD releases.

Bus

Bus configuration can be read and reset as before. An addition is that, besides "Missing" and "OK", "Added" is also shown if a unit has been fitted without resetting the bus list. Furthermore, "Not fitted" is shown for control modules that are not mounted and should not be mounted in the car. The bus list is divided into four pages, two for the I-bus, one for the P-bus and one for the O-bus.

With an "Add/Remove" of a control module updating of the list takes place automatically. In connection with the trouble code reading a check is made on the buses in accordance with the previous concept. Further tools have been introduced for fault diagnosis of the buses. A fault counter in each control module can be read and reset using the diagnostic tool. The counter's value increases with short term breaks to the control module in question.

Scheme 101

1. The customer's description of the problem constitutes a basis for the fault diagnosis strategy. If necessary, the customer must demonstrate the trouble on the car to avoid misunderstandings.
2. In certain cases, the function may be correct. Good product knowledge is required to decide this. If the function is correct, this must be explained to the customer.
3. If the function is judged to be faulty, the car should be repaired. Saab's fault diagnosis strategy assumes that the technician is familiar with the customer's description of the problem. So note the customer's complaint and any other observations on the job sheet.
4. The technician obtains a readout of the diagnostic trouble codes from all systems. A malfunction in one system can often be caused by a fault in another system.
5. The car may contain diagnostic trouble codes which are secondary faults or which have been incorrectly generated. Compare the customer complaint with the symptom description for the various diagnostic trouble codes. WIS has a quick search function for this purpose. If the symptom description for a diagnostic trouble code matches the customer's complaint, this diagnostic trouble code is probably caused by the primary fault. Repair as per instructions.
6. If there is no match with diagnostic trouble codes or symptoms, the technician must diagnose the fault himself. Search in WIS under fault diagnosis for symptoms in the system where the fault exists. Also check whether there is a TSB/MI in force. If the symptom description in the current system matches the complaint, the right fault diagnosis description has probably been found. Repair as per instructions.
7. Certain fault symptoms can be remedied by reprogramming the control module. Does the customer complaint stem from a known software problem in a programmable control module? Reprogram the control module following the instructions in SPS.
8. If there is no match with diagnostic trouble codes or symptoms, the technician must diagnose the fault himself. Good technical product knowledge is required to solve this type of problem.
9. A final check must be carried out after the repair.
10. The car is ready.

When the control module is supplied with current, the processor in it is tripped. The processor then reads the instructions stored in the control module's memory.

The control module is programmed to read the inputs and activate the outputs. If the control module program is faulty, the diagnostic trouble code "Internal Control Module Fault" will be generated.

The control module must be supplied with current before the system will function. The control module is supplied with current and the processor tripped when the control module can be contacted by the diagnostics instrument.

Outputs

The purpose of the system is to control a number of functions by means of various actuators, such as an injector or lamp. For the system to be capable of performing its functions, it must be possible to activate the actuators. For this reason the actuators must be connected to the control module and have a proper power supply or ground connection.

The performance of the majority of the actuators can be checked with the diagnostics instrument.

Inputs

A condition for the control module's capability of controlling its actuators is that the system's sensors supply it with correct values.

Sensor performance can be checked with the diagnostics instrument.

Scheme 102

The control module is sensitive to electrostatic discharges. In order to prevent damage to internal components in control modules, they must be changed very carefully in the following manner

1. Never touch the pins on a control module with your hands or clothes.
2. Ground yourself by touching the car body/engine. Unplug the connector on the car's control module.
3. Ground yourself by touching the car body/engine. Plug-in the connector on the car's control module.

SPS programming

Connect Tech2 and use TIS 2000 to check whether the control module requires programming. Go to the "SPS" menu, select "Read control module data" and follow the instructions. This is done so that the control module receives the latest available software and is also adapted to the car variant and market.

Add

Once the control module has been fitted and in certain cases SPS programming has been carried out, Tech2 must be used to marry the control unit to the car. Go to the "All" menu and select the control module under "Add/Remove". Then select "Add" and follow the instructions. The ignition key must be in ON position. TIS 2000 may be required.

The action involves the following

Properties files are downloaded, security codes are written, bus lists are updated, data in another control modules are updated and fault codes cleared in all control modules.

On-Board Diagnostics

1. The job of diagnostics is to detect faults and store them so that they can later be read off using the diagnostic tool.
2. Diagnostic trouble codes are the result of the fact that much of the software in modern control modules is constantly looking for faults. In an engine management system, for example, more than 50% of the program code nowadays is used entirely for diagnostics.
3. ISO/SAE has specified what diagnostic trouble codes should look like, which is a legal requirement in the USA. ISO/SAE determines all codes which have 0 in the second position.

Examples of diagnostic trouble codes

1. P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
2. P0303 Cylinder 3 Misfire Detected
3. P0601 Internal Control Module Memory Check Sum Error
4. P0705 Transmission Range Sensor Circuit Malfunction (PRNDL Input)

Table, standards for diagnostic trouble codes

Scheme 103

The following are monitored

1. Internal control module faults
2. Analog inputs
3. Digital inputs
4. Outputs

Internal Control Module Faults

Upon starting, the processor (CPU) checks that the check sum is the right on for the ROM. This value is written to the RAM and then read back again to check that the value is the same as the original one.

During operation, a check is carried out to ensure that the program executes certain routines.

See DIAGNOSTIC TROUBLE CODE P0601 for Trionic 8 by way of example.

1. The ROM has to be correct as the program is stored there. An error in the program could cause the control module to activate an output in the wrong position or make entirely wrong decisions. The check sum is the sum of the program's entire code and is attached when the control module is programmed. When the control module processor is woken, the entire program will be checked again. The check sum just calculated is compared with the programmed one, and these must be the same, otherwise diagnostic trouble code P0605 is generated.
2. All bytes in the RAM are checked in connection with startup. One byte equals 8 bits, and the process writes 4 different bit patterns and reads them back. The values written and read must be the same. 4 different bit patterns are used because we want to be sure that bits do not infect one another. The table below shows an example of how an error is detected in a byte in the RAM: ERROR REFERENCE Written Read Error (Yes/No) 00000000 00000000 No 11111111 11111111 No 01010101 01010101 No 10101010 10101011 Yes The error is that the second-last bit is infecting the last one with a one. This generates diagnostic trouble code P0604.
3. "Dog Error" is short for "Watchdog Error". A check is carried out to ensure that the program passes certain program steps which are always run.

Analog inputs

The voltage interval 0-5 V from a temperature sensor or pressure sensor is converted in the control module into a digital value, often 0-255 (256 steps), which is equivalent to a byte.

If we know that the bit value is never less than 10 or more than 245 under normal operation, we can set a diagnostic trouble code if the value falls outside of this range.

Diagnosis is unable to differentiate between interference and a short-circuit to 5 V. The reason for this is that the input has a Pull-Up at 5 V, and this is equivalent to a bit value of 255. This is the greatest value the control module can read. Thus interference generates the same diagnostic trouble code as a short-circuit to 5 V or B+.

The A/D value has to be too high for 0.5s in order to set the diagnostic trouble code. This is known as the filter time. The filter has to be in place to prevent short-term interference from mobile telephones or the ignition system, for example, from setting diagnostic trouble codes.

The diagnostic trouble code is set after 0.5s. The MIL (Malfunction Indicator Lamp) or Check Engine, as it is also known, is activated only during the second run in a row where faults have occurred. If the fault is rectified without deleting the diagnostic trouble code, Check Engine will go out after the third fault-free run.

The control module uses a substitute value for coolant temperature which is based on the intake air temperature.

As long as the fault is active, a bus message is sent indicating that the cooling temperature value is implausible. This means that the receiving control module is able to undertake certain action, such as starting the radiator fan and resetting the temperature gauge.

Digital Inputs

The camshaft and crankshaft sensor and a door switch are examples of digital inputs. These are more difficult to diagnose. In the case of the camshaft and crankshaft sensor, it may be concluded that there is a fault in the camshaft sensor if only the crankshaft sensor is transmitting signals (Motronic).

Buttons and many other digital inputs are often entirely without diagnostics.

You can see that simply switching on the ignition is not enough for the diagnostics to locate the fault. The crankshaft has to be rotating. If the camshaft is not rotating, the diagnostic trouble code will be set after 12 engine revolutions. If the fault is present from startup and the motor is unable to start without the sensor, it is necessary to turn the engine over on the starter motor before the code is set (e.g. Motronic).

If the cam chain snaps, the diagnostic trouble code will be set. The control module is unable to tell whether the camshaft sensor has stopped transmitting signals because of a mechanical fault or an electrical fault.

When at rest, when a last-stage transistor is not activated, the voltage between collector and emitter must be high (often battery voltage). When the transistor is active, the voltage must be low.

Otherwise a diagnostic trouble code is set.

Here, the control module first has to have learned that the car is fitted with A/C. This is saved to the RAM. Cars without A/C must not have this diagnostic trouble code stored, although they do not have an A/C relay.

For a diagnostic trouble code regarding interference to be set, the output must be deactivated. The correct voltage for an active output is 0 V.

If the voltage is too high in the case of an active output, a diagnostic trouble code for a short-circuit to B+ is set. This could be due to a burnt relay winding, a short-circuit in the network or made an incorrect connection in the relay base during troubleshooting.

"Warm-up" is short for the Warm-Up Cycle and is described in US legal requirements. A warm-up involves raising the engine temperature by 20°C, and the temperature also has to be in excess of 71°C. If the fault is rectified without deleting the diagnostic trouble code, the diagnostic trouble code will remain in the control module fault memory for 40 warm-ups.

Actions When Replacing Electrical Components

The components are sensitive to electrostatic discharges. In order to avoid damage to the internal circuits of components, replacement must be carried out with care in the following manner

1. Never touch the pins of the component with the hands or with clothing.
2. Ground yourself by touching the engine or body of the car. Unplug the connector from the component.
3. Ground yourself by touching the engine or body of the car. Plug in the connector to the component.

COMPONENTS LIST No. Name Location Graphic - Components - 541 SID, on top of instrument panel 630 SPA control module, 4D: in the luggage compartment behind the back rest member on the LH side 5D: on side of rear electrical center CV: under the luggage compartment electrical center 631RL Ultrasound distance sensor, outer left to the left of the rear bumper 631RLC Ultrasound distance sensor, center left to the left of the rear bumper 631RR Ultrasound distance sensor, outer right to the right of the rear bumper 631RRC Ultrasound distance sensor, center right to the right of the rear bumper 701 Main fuse box in the luggage compartment on the wall behind the rear left wheel housing See CIRCUIT PROTECTION DEVICES - 8 pin connector - H8-5 4D/CV: Below rear left light cluster 5D: Below rear electrical center - Crimp connections - J146 4D: Approx. 380 mm from rear electrical center 5D: Approx. 50 mm from grounding point grounding point G3 towards rear electrical center CRIMP J146, REAR HARNESS J151 Approx. 240 mm from the branching point connector H8-5 towards right-hand distance sensor CRIMP CONNECTION J151, REAR BUMPER HARNESS J152 Approx. 100 mm from the branching point connector H8-5 towards right distance sensor CRIMP CONNECTION J152, REAR BUMPER HARNESS J222 Approx. 120 mm from the branching point to the LH rear wing light cluster towards the luggage-compartment lighting CRIMP CONNECTION J222, REAR HARNESS CV - Grounding points - G3 4D/CV: In luggage compartment below left-hand light cluster GROUNDING POINT G3, 4D - 5D: On rear left luggage compartment floor support GROUNDING POINT G3, 5D GROUNDING POINT G3, (CV)

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Scheme 107