
3.0
SYSTEM DESCRIPTION AND FUNCTIONAL OPERATION
The body system on the 1999 300M consists of a combination of modules that communicate over
the PCI bus (Programmable Communication Interface multiplex system). Through the PCI bus,
information about the operation of vehicle components and circuits is relayed quickly to the
appropriate module(s). All modules receive all the information transmitted on the bus even though
a module may not require all information to perform it’s function. It will only respond to messages
9
addressed
9
to it through a binary coding process. This method of data transmission significantly
reduces the complexity of the wiring in the vehicle and the size of wiring harnesses. All of the
information about the functioning of all the systems is organized, controlled, and communicated
by the PCI bus, which is described in Section 3.14 (Vehicle Communication) of this general
information.
3.1
Airbag System
The Airbag Control Module (ACM) is secured to a bracket on the floor panel transmission tunnel
below the instrument panel inside the vehicle. The ACM mounting bracket also serves as the
instrument panel center support. The ACM contains a microprocessor, the impact sensor, and
energy storage capacitor. The microprocessor contains the airbag system logic. The ACM system
logic includes On-Board Diagnostics (OBD) capability, and communicates with the instrument
cluster circuitry on the Programmable Communication Interface (PCI) data bus to control the
airbag indicator lamp. The microprocessor in the ACM monitors the impact sensor signal and the
airbag system electrical circuits to determine the system readiness. If the ACM detects a
monitored system fault, it sends messages to the instrument cluster on the PCI data bus to turn
on the airbag indicator lamp. A pre-programmed decision algorithm in the ACM microprocessor
determines when the deceleration rate is severe enough to require airbag system protection.
When the programmed conditions are met, the ACM sends an electrical signal to deploy the
airbag system components. The impact sensor is an accelerometer that senses the rate of vehicle
deceleration, which provides verification of the direction and severity of an impact. The impact
sensor is calibrated for the specific vehicle, and is only serviced as a unit with the ACM. The ACM
also contains an energy-storage capacitor. This capacitor stores enough electrical energy to
deploy the airbags, for one second following a battery disconnect or failure during an impact. The
purpose of the capacitor is to provide airbag system protection in a severe secondary impact if the
initial impact has damaged or disconnected the battery, but was not severe enough to deploy the
airbags.
THE AIRBAG SYSTEM IS A SENSITIVE, COMPLEX ELECTROMECHANICAL UNIT. BEFORE
ATTEMPTING TO DIAGNOSE OR SERVICE ANY AIRBAG SYSTEM OR RELATED STEERING
WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENTS YOU MUST FIRST
DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE. WAIT TWO
MINUTES FOR THE SYSTEM CAPACITOR TO DISCHARGE BEFORE FURTHER SYSTEM
SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO
DO THIS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY. NEVER STRIKE OR KICK THE AIRBAG CONTROL MODULE, AS IT
CAN DAMAGE THE IMPACT SENSOR OR AFFECT ITS CALIBRATION. IF AN AIRBAG
CONTROL MODULE IS ACCIDENTALLY DROPPED DURING SERVICE, THE MODULE MUST
BE SCRAPPED AND REPLACED WITH A NEW UNIT.
The airbag warning lamp is the only point at which the customer can observe
9
symptoms
9
of a
system malfunction. Whenever the ignition key is turned to the
9
run
9
or
9
start
9
position, the MIC
performs a lamp check by turning the AIRBAG warning lamp on for 6-8 seconds. If the lamp
remains off, it means that the ACM has checked the system and found it to be free of discernible
malfunctions. If the lamp remains on, there could be an active fault in the system or the MIC lamp
circuit may be internally shorted to ground. If the lamp comes on and stays on for a period longer
than 6-8 seconds then goes off, there is usually an intermittent problem in the system.
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Содержание 300M 1999
Страница 30: ...NOTES G E N E R A L I N F O R M A T I O N 20 ...
Страница 32: ...4 3 Fuse Block Junction Block 4 4 Airbag System G E N E R A L I N F O R M A T I O N 22 ...
Страница 33: ...4 5 Audio System G E N E R A L I N F O R M A T I O N 23 ...
Страница 34: ...4 5 Audio System continued G E N E R A L I N F O R M A T I O N 24 ...
Страница 35: ...4 6 Body Control Module and Junction Block G E N E R A L I N F O R M A T I O N 25 ...
Страница 37: ...4 7 2 Manual Temp Control G E N E R A L I N F O R M A T I O N 27 ...
Страница 38: ...4 7 2 Manual Temp Control continued 4 7 3 ATC and MTC G E N E R A L I N F O R M A T I O N 28 ...
Страница 39: ...4 8 Chime 4 9 Door Ajar G E N E R A L I N F O R M A T I O N 29 ...
Страница 40: ...4 9 Door Ajar continued 4 10 Exterior Interior Lighting G E N E R A L I N F O R M A T I O N 30 ...
Страница 41: ...G E N E R A L I N F O R M A T I O N 31 ...
Страница 42: ...4 11 Instrument Cluster FUEL TANK SENDING UNIT G E N E R A L I N F O R M A T I O N 32 ...
Страница 43: ...4 12 Memory System G E N E R A L I N F O R M A T I O N 33 ...
Страница 44: ...4 12 Memory System continued G E N E R A L I N F O R M A T I O N 34 ...
Страница 45: ...4 13 OTIS G E N E R A L I N F O R M A T I O N 35 ...
Страница 46: ...4 13 OTIS continued 4 14 Power Door Locks RKE G E N E R A L I N F O R M A T I O N 36 ...
Страница 47: ...G E N E R A L I N F O R M A T I O N 37 ...
Страница 48: ...4 15 Sentry Key Immobilizer System 4 16 Vehicle Communication System G E N E R A L I N F O R M A T I O N 38 ...
Страница 49: ...ABS PCM TCM G E N E R A L I N F O R M A T I O N 39 ...
Страница 50: ...4 17 Vehicle Theft Security System G E N E R A L I N F O R M A T I O N 40 ...
Страница 51: ...4 18 Wiper System G E N E R A L I N F O R M A T I O N 41 ...
Страница 52: ...4 18 Wiper System continued G E N E R A L I N F O R M A T I O N 42 ...
Страница 55: ...6 0 FIELD EXPERIENCE NOTES G E N E R A L I N F O R M A T I O N 45 ...
Страница 56: ...NOTES G E N E R A L I N F O R M A T I O N 46 ...
Страница 57: ...7 0 DIAGNOSTIC INFORMATION AND PROCEDURES 7 1 GENERAL TROUBLESHOOTING 47 ...
Страница 62: ...TEST 2A REPAIRING CLUSTER MESSAGE MISMATCH Perform TEST 1A Before Proceeding A I R B A G S Y S T E M 52 ...
Страница 66: ...TEST 3A CONTINUED REPAIRING DRIVER SQUIB CIRCUIT OPEN FIG 1 FIG 2 A I R B A G S Y S T E M 56 ...
Страница 76: ...TEST 7A CONTINUED REPAIRING LOSS OF IGNITION RUN ONLY FIG 1 FIG 2 FIG 3 A I R B A G S Y S T E M 66 ...
Страница 80: ...TEST 8A CONTINUED REPAIRING LOSS OF IGNITION RUN START FIG 1 FIG 2 FIG 3 A I R B A G S Y S T E M 70 ...
Страница 84: ...TEST 10A REPAIRING NO CLUSTER IFR MESSAGE Perform TEST 1A Before Proceeding A I R B A G S Y S T E M 74 ...
Страница 86: ...TEST 11A REPAIRING NO PCI COMMUNICATION Perform TEST 1A Before Proceeding A I R B A G S Y S T E M 76 ...
Страница 96: ...TEST 16A REPAIRING POWER STAGE NOT TESTED Perform TEST 1A Before Proceeding A I R B A G S Y S T E M 86 ...
Страница 98: ...TEST 17A REPAIRING WARNING LAMP OPEN SHORTED Perform TEST 1A Before Proceeding A I R B A G S Y S T E M 88 ...
Страница 100: ...TEST 18A REPAIRING STORED TROUBLE CODES Perform TEST 1A Before Proceeding A I R B A G S Y S T E M 90 ...
Страница 102: ...TEST 19A AIRBAG CONTROL MODULE REPLACEMENT PROCEDURE Perform TEST 1A Before Proceeding A I R B A G S Y S T E M 92 ...
Страница 108: ...TEST 1C REPAIRING SHORTED FRONT CHANNEL Perform TEST 1A Before Proceeding FIG 1 FIG 2 A U D I O S Y S T E M S 98 ...
Страница 110: ...TEST 1C CONTINUED REPAIRING SHORTED FRONT CHANNEL FIG 1 FIG 2 A U D I O S Y S T E M S 100 ...
Страница 112: ...TEST 1D REPAIRING SHORTED REAR CHANNEL Perform TEST 1A Before Proceeding FIG 1 A U D I O S Y S T E M S 102 ...
Страница 114: ...TEST 1D CONTINUED REPAIRING SHORTED REAR CHANNEL FIG 1 A U D I O S Y S T E M S 104 ...
Страница 116: ...TEST 1E REPAIRING SHORTED LEFT CHANNEL Perform TEST 1A Before Proceeding FIG 1 FIG 2 A U D I O S Y S T E M S 106 ...
Страница 118: ...TEST 1E CONTINUED REPAIRING SHORTED LEFT CHANNEL FIG 1 FIG 2 A U D I O S Y S T E M S 108 ...
Страница 120: ...TEST 1F REPAIRING SHORTED RIGHT CHANNEL Perform TEST 1A Before Proceeding FIG 1 FIG 2 A U D I O S Y S T E M S 110 ...
Страница 122: ...TEST 1F CONTINUED REPAIRING SHORTED RIGHT CHANNEL FIG 1 FIG 2 A U D I O S Y S T E M S 112 ...
Страница 222: ...TEST 2A REPAIRING CHIME INOPERATIVE AT ALL TIMES Perform TEST 1A Before Proceeding C H I M E S Y S T E M 212 ...
Страница 224: ...TEST 3A REPAIRING CHIME INOPERATIVE WITH EXTERIOR LAMPS ON Perform TEST 1A Before Proceeding C H I M E S Y S T E M 214 ...
Страница 230: ...TEST 6A REPAIRING CHIME BEEP REQUEST INOPERATIVE Perform TEST 1A Before Proceeding C H I M E S Y S T E M 220 ...
Страница 236: ...TEST 9A REPAIRING CHIME SOUNDS WITH DRIVER DOOR OPEN Perform TEST 1A Before Proceeding FIG 1 C H I M E S Y S T E M 226 ...
Страница 260: ...TEST 2A CONTINUED REPAIRING HEADLAMP SWITCH INPUT FAILURE FIG 1 FIG 2 E X T E R I O R L I G H T I N G S Y S T E M 250 ...
Страница 274: ...TEST 4A CONTINUED REPAIRING LOW BEAM HEADLAMPS THAT WILL NOT TURN OFF E X T E R I O R L I G H T I N G S Y S T E M 264 ...
Страница 298: ...TEST 9A CONTINUED REPAIRING FOG LAMPS THAT WILL NOT TURN ON FIG 1 E X T E R I O R L I G H T I N G S Y S T E M 288 ...
Страница 308: ...TEST 2A CONTINUED REPAIRING FUEL LEVEL SENDING UNIT FAILURE I N S T R U M E N T C L U S T E R 298 ...
Страница 312: ...TEST 3A CONTINUED REPAIRING DIMMING LEVEL SWITCH FAILURE FIG 1 I N S T R U M E N T C L U S T E R 302 ...
Страница 316: ...TEST 5A IDENTIFYING THE INOPERATIVE GAUGE Perform TEST 1A Before Proceeding FIG 1 I N S T R U M E N T C L U S T E R 306 ...
Страница 318: ...TEST 5A CONTINUED IDENTIFYING THE INOPERATIVE GAUGE NOTES I N S T R U M E N T C L U S T E R 308 ...
Страница 322: ...TEST 7A IDENTIFYING WARNING LAMP PROBLEMS Perform TEST 1A Before Proceeding NOTES I N S T R U M E N T C L U S T E R 312 ...
Страница 326: ...TEST 8A REPAIRING PRND3L INDICATOR MALFUNCTIONS Perform TEST 1A Before Proceeding I N S T R U M E N T C L U S T E R 316 ...
Страница 332: ...TEST 9B CONTINUED REPAIRING PANEL ILLUMINATION SHORTED TO BATTERY FIG 1 I N S T R U M E N T C L U S T E R 322 ...
Страница 336: ...TEST 9C CONTINUED REPAIRING PANEL ILLUMINATION SHORTED TO GROUND FIG 1 I N S T R U M E N T C L U S T E R 326 ...
Страница 338: ...TEST 10A REPAIRING FAULTY GAUGE Perform TEST 5A Before Proceeding NOTES I N S T R U M E N T C L U S T E R 328 ...
Страница 344: ...TEST 12A CONTINUED REPAIRING FUEL GAUGE LED OPERATION I N S T R U M E N T C L U S T E R 334 ...
Страница 350: ...TEST 13A REPAIRING SPEEDOMETER OPERATION Perform TEST 5A Before Proceeding NOTES I N S T R U M E N T C L U S T E R 340 ...
Страница 356: ...TEST 15A CONTINUED REPAIRING OIL PRESSURE WARNING LAMP OPERATING IMPROPERLY FIG 1 I N S T R U M E N T C L U S T E R 346 ...
Страница 360: ...TEST 16A REPAIRING SEAT BELT LED Perform TEST 1A Before Proceeding NOTES I N S T R U M E N T C L U S T E R 350 ...
Страница 374: ...TEST 19A REPAIRING DOOR AJAR INDICATOR Perform TEST 1A Before Proceeding I N S T R U M E N T C L U S T E R 364 ...
Страница 376: ...TEST 19A CONTINUED REPAIRING DOOR AJAR INDICATOR NOTES I N S T R U M E N T C L U S T E R 366 ...
Страница 380: ...TEST 20A CONTINUED REPAIRING TRUNK AJAR INDICATOR FIG 1 I N S T R U M E N T C L U S T E R 370 ...
Страница 398: ...TEST 5A CONTINUED REPAIRING COURTESY LAMPS ON AT ALL TIMES FIG 1 I N T E R I O R L I G H T I N G S Y S T E M 388 ...
Страница 488: ...TEST 21A CONTINUED REPAIRING LEFT SEAT HEAT OUTPUT OPEN TROUBLE CODE FIG 1 FIG 2 M E M O R Y S Y S T E M 478 ...
Страница 492: ...TEST 22A CONTINUED REPAIRING LEFT SEAT HEAT OUTPUT SHORTED TO GROUND TROUBLE CODE FIG 1 M E M O R Y S Y S T E M 482 ...
Страница 504: ...TEST 27A CONTINUED REPAIRING LEFT THERMISTOR OUT OF RANGE HIGH TROUBLE CODE FIG 1 M E M O R Y S Y S T E M 494 ...
Страница 508: ...TEST 28A CONTINUED REPAIRING RIGHT SEAT HEAT OUTPUT OPEN TROUBLE CODE FIG 1 FIG 2 M E M O R Y S Y S T E M 498 ...
Страница 512: ...TEST 29A CONTINUED REPAIRING RIGHT SEAT HEAT OUTPUT SHORTED TO GROUND TROUBLE CODE FIG 1 M E M O R Y S Y S T E M 502 ...
Страница 524: ...TEST 34A CONTINUED REPAIRING RIGHT THERMISTOR OUT OF RANGE HIGH TROUBLE CODE FIG 1 M E M O R Y S Y S T E M 514 ...
Страница 542: ...TEST 43A REPAIRING INOPERATIVE MEMORY SWITCH Perform TEST 1A Before Proceeding FIG 1 M E M O R Y S Y S T E M 532 ...
Страница 544: ...TEST 43A CONTINUED REPAIRING INOPERATIVE MEMORY SWITCH FIG 1 FIG 2 M E M O R Y S Y S T E M 534 ...
Страница 546: ...TEST 43B REPAIRING INOPERATIVE MEMORY SWITCH Perform TEST 43A Before Proceeding FIG 1 FIG 2 M E M O R Y S Y S T E M 536 ...
Страница 548: ...TEST 43C REPAIRING INOPERATIVE MEMORY SWITCH Perform TEST 43A Before Proceeding FIG 1 FIG 2 M E M O R Y S Y S T E M 538 ...
Страница 634: ...TEST 2A CONTINUED REPAIRING AIRBAG CONTROL MODULE NO RESPONSE FIG 1 FIG 2 V E H I C L E C O M M U N I C A T I O N 624 ...
Страница 644: ...TEST 4A CONTINUED REPAIRING BODY CONTROL MODULE NO RESPONSE FIG 1 FIG 2 V E H I C L E C O M M U N I C A T I O N 634 ...
Страница 646: ...TEST 4A CONTINUED REPAIRING BODY CONTROL MODULE NO RESPONSE FIG 1 V E H I C L E C O M M U N I C A T I O N 636 ...
Страница 662: ...TEST 9A CONTINUED REPAIRING RADIO NO RESPONSE CONDITION FIG 1 V E H I C L E C O M M U N I C A T I O N 652 ...
Страница 672: ...TEST 12A CONTINUED REPAIRING PCI BUS CIRCUIT SHORTED TO BATTERY V E H I C L E C O M M U N I C A T I O N 662 ...
Страница 678: ...TEST 13A CONTINUED REPAIRING PCI BUS CIRCUT SHORTED TO GROUND V E H I C L E C O M M U N I C A T I O N 668 ...
Страница 688: ...TEST 2A DISARMING THE SYSTEM Perform TEST 1A Before Proceeding V E H I C L E T H E F T S E C U R I T Y S Y S T E M 678 ...
Страница 692: ...TEST 3A CONTINUED REPAIRING VTSS INDICATOR LAMP STAYS ON FIG 1 V E H I C L E T H E F T S E C U R I T Y S Y S T E M 682 ...
Страница 710: ...TEST 5A CONTINUED REPAIRING WIPERS NOT WORKING AT ALL FIG 1 W I N D S H I E L D W I P E R S Y S T E M 700 ...
Страница 714: ...TEST 5B CONTINUED REPAIRING WIPERS NOT WORKING AT ALL FIG 1 W I N D S H I E L D W I P E R S Y S T E M 704 ...
Страница 748: ...TEST VER 4A VERIFICATION TEST MEMORY SYSTEM NOTES V E R I F I C A T I O N T E S T 738 ...
Страница 751: ...10 0 SCHEMATIC DIAGRAMS 10 1 Airbag System G E N E R A L I N F O R M A T I O N 741 ...
Страница 752: ...10 2 Body Control Module G E N E R A L I N F O R M A T I O N 742 ...
Страница 753: ...10 3 Audio Systems Midline Premium G E N E R A L I N F O R M A T I O N 743 ...
Страница 754: ...10 3 Audio Systems Premium 2 10 4 Chime Warning System G E N E R A L I N F O R M A T I O N 744 ...
Страница 755: ...10 5 Climate Control Automatic Temperature Control G E N E R A L I N F O R M A T I O N 745 ...
Страница 756: ...10 5 Climate Control Manual Temperature Control 10 6 Door Ajar G E N E R A L I N F O R M A T I O N 746 ...
Страница 757: ...10 7 Exterior Lighting G E N E R A L I N F O R M A T I O N 747 ...
Страница 758: ...10 8 Instrument Cluster 10 9 Interior Lighting G E N E R A L I N F O R M A T I O N 748 ...
Страница 759: ...10 9 Interior Lighting G E N E R A L I N F O R M A T I O N 749 ...
Страница 760: ...10 10 Memory System G E N E R A L I N F O R M A T I O N 750 ...
Страница 761: ...10 11 OTIS G E N E R A L I N F O R M A T I O N 751 ...
Страница 762: ...10 12 Power Door Locks RKE G E N E R A L I N F O R M A T I O N 752 ...
Страница 763: ...10 13 Vehicle Communications 10 14 Vehicle Theft Security System G E N E R A L I N F O R M A T I O N 753 ...
Страница 764: ...10 15 Wiper System G E N E R A L I N F O R M A T I O N 754 ...
Страница 766: ...756 ...