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Data Link Communications System GMC Savana I

Communication Devices 14 illustrations ~2667 words

MODEL IDENTIFICATION

MakeModel
ChevroletCutaway
ChevroletChevy Express
ChevroletRV Cutaway
GMCSavana
GMCSavana Camper Special
GMCSavana Special

MODEL IDENTIFICATION

DESCRIPTION & OPERATION

WARNINGVehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.
CAUTIONWhen battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery.

The Data Link Connector (DLC) is used as an access point for different vehicle diagnostic and programming functions involving the use of a scan tool.

UART DATA LINE

The UART serial data communication relies on a 5-volt digital signal for the exchange of data between different control modules and a scan tool. When the ignition is in RUN and there is no data transmission, there is a constant 5 volts on the data line. Communication on the line brings the voltage to 0 volts. The supplemental restraint Sensing and Diagnostic Module (SDM) communicates on the UART data line.

CLASS 2 DATA LINE

Modules on the Class 2 data line transmit state of health messages every two seconds to indicate proper functioning to other modules on the data line. Some modules recognize when other modules are not communicating. A Diagnostic Trouble Code (DTC) may be stored by a module that detects five seconds of non-communication from another module. Data line DTCs begin with the letter "U" and may be caused by faulty data line wiring, faulty module power or ground or a faulty control module.

REMOTE CONTROL DOOR LOCK RECEIVER DATA LINE

The DLC provides a connection to the Remote Control Door Lock Receiver (RCDLR) to allow programming the receiver to recognize specific remote control door lock transmitters.

REMOTE CONTROL DOOR LOCK RECEIVER PROGRAMMING

The remote control door lock receiver may be programmed by a scan tool when connected to the DLC.

COMPONENT LOCATIONS

ComponentLocation
Convenience CenterUnder Driver Side Of Instrument Panel. (Scheme 1)
Data Link Connector (DLC)Under Driver Side Of Instrument Panel Mounted To Bottom Of Knee Bolster. (Scheme 2)
Electric Brake Control Module (EBCM)On Driver Side Frame Rail, Near Center Of Vehicle. (Scheme 3)
Inflatable Restraint Sensing & Diagnostic Module (SDM)Under Driver Seat. (Scheme 4)
Instrument Panel Fuse BlockBehind Lower Driver Side Kick Panel. (Scheme 5)
Passlock(tm) ModuleUnder Center Of Instrument Panel. (Scheme 6)
Powertrain Control Module (PCM)Behind Center Of Instrument Panel. (Scheme 7)
Remote Control Door Lock Receiver (RCDLR)Behind Instrument Panel, In Center Of Bulkhead. (Scheme 8)
Vehicle Control Module (VCM)Engine Compartment, On Left Fender. (Scheme 9)
C100Driver Rear Of Engine Compartment At Bulkhead. (Scheme 5)& (Scheme 9)
C210Crossbody Harness, Under Driver Side Of Instrument Panel Near Brake Pedal, At Convenience Center. (Scheme 1)
G101 (6.5L)Engine Harness, Near Thermostat Housing. (Scheme 10)
G101 ( 7.4L)Engine Harness, Near Thermostat Housing. (Scheme 11)
G200Instrument Panel Harness, Behind Left Kick Panel, Near Instrument Panel Fuse Block. (Scheme 12)
P100In Driver Rear Of Engine Compartment, At Bulkhead. (Scheme 9)
P101Under Passenger Side Of Instrument Panel
S102 (4.3L)Engine Harness, Near Underhood Fuse-Relay Center, Toward A/C Compressor Breakout
S102 (5.0L, 5.7L)Engine Harness, Near A/C Compressor Breakout, Toward MAF Sensor Breakout
S102 (6.5L)Engine Harness, Near Main Harness Breakout Leading To Blower Motor, Toward C100 Breakout
S102 (7.4L)Engine Harness, Near Main Harness Leading To A/C Compressor Breakout, Toward Generator Breakout
S153 (4.3L)Engine Harness, Near A/C Compressor Breakout, Toward Transmission
S153 (5.0 & 5.7L)Engine Harness, Near Ignition Coil Breakout, Toward Transmission
S153 (6.5L)Engine Harness, Near Main Harness Breakout Leading To Underhood Fuse/Relay Center and C100
S153 (7.4L)Engine Harness, Near C100 Breakout, Toward EGR Sensor Breakout
S201Instrument Panel Harness, Near Parking Brake Warning Switch Breakout, Toward DLC Breakout
S207Instrument Panel Harness, On VSS Buffer Breakout
S218Instrument Panel Harness, Near Instrument cluster Breakout, Toward HVAC Switch Breakout
S254Instrument Panel Harness, On DLC Breakout

COMPONENT LOCATIONS

Scheme 1

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Scheme 1

Scheme 2

Scheme 2
Scheme 2

Scheme 3

Scheme 3
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Scheme 4

Scheme 4
Scheme 4

Scheme 5

Scheme 5
Scheme 5

Scheme 6

Scheme 6
Scheme 6

Scheme 7

Scheme 7
Scheme 7

Scheme 8

Scheme 8
Scheme 8

Scheme 9

Scheme 9
Scheme 9

Scheme 10

Scheme 10
Scheme 10

Scheme 11

Scheme 11
Scheme 11

Scheme 12

Scheme 12
Scheme 12

PRELIMINARY INSPECTION

Verify customer complaint by operating suspected system. Visually inspect for obvious signs of mechanical and electrical damage. Inspect for blown fuses and damaged relays. Inspect for loose or corroded connections, damaged wiring harnesses and/or switches. Check for a broken or partially broken wire inside insulation, which could cause system malfunction but prove good in a continuity/voltage check with system disconnected. Ensure any aftermarket electronic equipment is properly installed. If fault is found, repair as necessary. If no fault is found, perform self-diagnostics. See SELF-DIAGNOSTIC SYSTEM .

SELF-DIAGNOSTIC SYSTEM

For information on how to retrieve and clear DTCs, see scan tool instruction manual and appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If any communication related DTCs are present, If no DTCs are present, go to DIAGNOSTIC TROUBLE CODE DEFINITIONS table.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

DTC (1)Description
U1016 (2)Loss Of Communications With PCM
U1041 (2)Loss Of EBCM Communication
U1192 (2)Loss Of Passlock(tm) Class 2 Communication
U1255 (2)Serial Data Line Malfunction
(1) Codes listed in this table are only for testing covered in this article. For a complete list of codes, see appropriate SELF-DIAGNOSTICS article. (2) For DTC diagnosis, see DTC U1016, U1041 & U1192 .
(1)Codes listed in this table are only for testing covered in this article. For a complete list of codes, see appropriate SELF-DIAGNOSTICS article.
(2)For DTC diagnosis, see DTC U1016, U1041 & U1192 .

DIAGNOSTIC TROUBLE CODE DEFINITIONS

Description

The Control Module ID Number list provides a method for determining which module is not communicating. A module with an internal Class 2 serial data circuit malfunction or which loses power during the current ignition cycle would have a lost communication DTC set by other modules. Use the following Control Module ID Number list in order to determine which module is not communicating

  1. DTC U1016 Powertrain Control Module (PCM)/Vehicle Control Module (VCM)
  2. DTC U1041 Electronic Brake Control Module (EBCM)
  3. DTC U1192 Vehicle Theft Deterrent Passlock(tm) Module (VTD)

Modules connected to the Class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for State of Health monitoring (Node Alive messages).

A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module's Node Alive message. Each module on the Class 2 serial data circuit which is powered and performing functions that require detection of a communications malfunction is required to send a Node Alive message every two seconds. When no message is detected from a learned identification number for five seconds, a DTC U1XXX (where XXX is equal to the three digit identification number) is set.

DTC Parameters

  1. The vehicle power mode (ignition switch position) requires serial data communication to occur.
  2. A message from a learned identification number has not been detected for the past 5 seconds.

Diagnostic Procedure

An intermittent open, short to ground, or short to voltage between the inoperative module and the data line may cause this code to set. A poor connection at the inoperative module or the data line may cause this code to set. An intermittent open in the data line may cause this code to set.

  1. Perform diagnostic system check for module that is not communicating. See the following. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. See «DIAGNOSTIC SYSTEM OPERATION CHECK - ANTI-THEFT»(/gmc/savana/i-1996-2002/remont/door-locks-anti-theft-systems/#anti-theft-system__diagnostic-system-operation-check-anti-theft) in ANTI-THEFT SYSTEMS article. See «DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/anti-locktraction-control/#anti-lock-brake-system__diagnostic-system-check) in ANTI-LOCK BRAKES article in BRAKES. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-controls-tests-wcodes-diesel__on-board-diagnostic-obd-system-check) in TESTS W/ CODES - DIESEL article in ENGINE PERFORMANCE. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) in TESTS W/ CODES - GASOLINE article in ENGINE PERFORMANCE. If no fault is found, go to next step. If a fault is found, repair and go to step 6.
  2. Test Class 2 serial data circuit of module that is not communicating for an open between itself and module reporting "U" code. (Scheme 14) If no fault is found, go to next step. If a fault is found, repair as necessary and go to step 5.
  3. Inspect for poor connections/terminal tension at Class 2 serial data circuit(s) of module that is not communicating. If no fault is found, go to next step. If a fault is found, repair as necessary and go to step 5.
  4. Replace module that is not communicating. See «SENSING & DIAGNOSTIC MODULE (SDM)»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS, «ANTI-THEFT MODULE (UA6)»(/gmc/savana/i-1996-2002/remont/door-locks-anti-theft-systems/#anti-theft-system__anti-theft-module) in ANTI-THEFT SYSTEMS article, «ELECTRONIC BRAKE CONTROL MODULE (EBCM)»(/gmc/savana/i-1996-2002/remont/anti-locktraction-control/#anti-lock-brake-system) in ANTI-LOCK BRAKES article in BRAKES or «POWERTRAIN CONTROL MODULE (PCM)»(/gmc/savana/i-1996-2002/remont/removal-installation/#engine-controls-removal-installation-trucks__powertrain-control-module-pcm) in REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. Go to step 7.
  5. Install a scan tool. Turn on ignition leaving engine off. Select "display DTCs" function for module which was not communicating. If module does not display any DTCs which do not begin with a "U", go to next step. If scan tool displays any DTCs which do not begin with a "U", diagnose and repair as necessary.
  6. Clear DTCs using scan tool. Go to next step.
  7. Select "display DTCs" function for module(s) which had Lost Communications with U1XXX DTC set. If scan tool does not display any DTCs which do not begin with a "U", go to next step. If scan tool displays any DTCs that do not begin with a "U", diagnose and repair as necessary.
  8. Clear DTCs using scan tool. Continue diagnosing or clearing DTCs until all modules have been diagnosed and all DTCs have been cleared. System should be okay.

A current DTC will clear when a Node Alive message from the failed identification number is detected on the Class 2 serial data circuit or at the end of the current ignition cycle. A history DTC will clear upon receipt of a scan tool "clear DTCs" command.

  1. With scan tool connected make contact with any of the modules applicable to vehicle. If scan tool screen is blank or scan tool does not power up, see «SCAN TOOL INOPERATIVE/DOES NOT COMMUNICATE WITH COMPONENTS»(/gmc/savana/i-1996-2002/remont/communication-devices/#data-link-communications-system__scan-tool-inoperativedoes-not-communicate-with) .
  2. Select "diagnostics circuit check, Class 2 DTC check" from scan tool menu. If there are any DTCs that start with a "U", see «DTC U1016: LOSS OF COMMUNICATIONS WITH PCM, DTC U1041: LOSS OF EBCM COMMUNICATION & DTC U1192: LOSS OF PASSLOCK(tm) CLASS 2 COMMUNICATION»(/gmc/savana/i-1996-2002/remont/communication-devices/#data-link-communications-system) under DIAGNOSTIC TESTS. If there is no communication with vehicle or with data link connector, see «SCAN TOOL INOPERATIVE/DOES NOT COMMUNICATE WITH COMPONENTS»(/gmc/savana/i-1996-2002/remont/communication-devices/#data-link-communications-system__scan-tool-inoperativedoes-not-communicate-with) .
  3. Select "body diagnostics" from scan tool menu. Select "SIR UART Data Line information". Access DTCs using scan tool. If there is no communication with vehicle or with data link connector, see «SCAN TOOL DOES NOT COMMUNICATE WITH UART DATA LINE»(/gmc/savana/i-1996-2002/remont/communication-devices/#data-link-communications-system__scan-tool-does-not-communicate-with) .
  4. Establish communication with Electronic Brake Control Module (EBCM). Access DTCs using scan tool. If there is no communication with vehicle or with data link connector, see «DTC U1016: LOSS OF COMMUNICATIONS WITH PCM, DTC U1041: LOSS OF EBCM COMMUNICATION & DTC U1192: LOSS OF PASSLOCK(tm) CLASS 2 COMMUNICATION»(/gmc/savana/i-1996-2002/remont/communication-devices/#data-link-communications-system) under DIAGNOSTIC TESTS.
  5. Establish communication with PCM/VCM. Access DTCs using scan tool. If there is no communication with vehicle or with data link connector, see «DTC U1016: LOSS OF COMMUNICATIONS WITH PCM, DTC U1041: LOSS OF EBCM COMMUNICATION & DTC U1192: LOSS OF PASSLOCK(tm) CLASS 2 COMMUNICATION»(/gmc/savana/i-1996-2002/remont/communication-devices/#data-link-communications-system) under DIAGNOSTIC TESTS.

SCAN TOOL INOPERATIVE/DOES NOT COMMUNICATE WITH COMPONENTS

  1. If scan tool powers up, go to next step. If scan tool does not power up, go to step 5.
  2. Ensure scan tool is operating correctly by connecting scan tool to a different vehicle. If scan tool is functioning properly, return to original vehicle and go to next step. If scan tool is malfunctioning, refer to scan tool owners manual.
  3. Turn ignition to OFF position. Disconnect scan tool from Data Link Connector (DLC). Inspect for poor connections/terminal tension at DLC terminals No. 2, 4, 5 and 16. (Scheme 13) If there is no fault with DLC, go to next step. If there is any fault, repair as necessary and perform diagnostic system check for module that is not communicating. See the following. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. See «DIAGNOSTIC SYSTEM OPERATION CHECK - ANTI-THEFT»(/gmc/savana/i-1996-2002/remont/door-locks-anti-theft-systems/#anti-theft-system__diagnostic-system-operation-check-anti-theft) in ANTI-THEFT SYSTEMS article. See «DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/anti-locktraction-control/#anti-lock-brake-system__diagnostic-system-check) in ANTI-LOCK BRAKES article in BRAKES. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-controls-tests-wcodes-diesel__on-board-diagnostic-obd-system-check) in SELF-DIAGNOSTICS - DIESEL article in ENGINE PERFORMANCE. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) in SELF-DIAGNOSTICS - GASOLINE article in ENGINE PERFORMANCE.
  4. Test DLC ground circuits at terminals No. 4 and 5 for an open. (Scheme 13)and (Scheme 14). If there is no fault with ground circuits, go to next step. If there is fault with ground circuits, repair as necessary and perform diagnostic system check for module that is not communicating. See the following. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. See «DIAGNOSTIC SYSTEM OPERATION CHECK - ANTI-THEFT»(/gmc/savana/i-1996-2002/remont/door-locks-anti-theft-systems/#anti-theft-system__diagnostic-system-operation-check-anti-theft) in ANTI-THEFT SYSTEMS article. See «DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/anti-locktraction-control/#anti-lock-brake-system__diagnostic-system-check) in ANTI-LOCK BRAKES article in BRAKES. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-controls-tests-wcodes-diesel__on-board-diagnostic-obd-system-check) in SELF-DIAGNOSTICS - DIESEL article in ENGINE PERFORMANCE. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) in SELF-DIAGNOSTICS - GASOLINE article in ENGINE PERFORMANCE.
  5. Ensure battery power is present at DLC terminal No. 16. (Scheme 13) If there is battery power, go to next step. If there is not battery power, go to step 8.
  6. Test Class 2 serial data circuit for an open or short to ground in 1807 circuit wire. (Scheme 14) If there is no fault with the 1807 circuit, go to next step. If there is fault with the 1807 circuit, repair as necessary and perform diagnostic system check for module that is not communicating. See the following. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. See «DIAGNOSTIC SYSTEM OPERATION CHECK - ANTI-THEFT»(/gmc/savana/i-1996-2002/remont/door-locks-anti-theft-systems/#anti-theft-system__diagnostic-system-operation-check-anti-theft) in ANTI-THEFT SYSTEMS article. See «DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/anti-locktraction-control/#anti-lock-brake-system__diagnostic-system-check) in ANTI-LOCK BRAKES article in BRAKES. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-controls-tests-wcodes-diesel__on-board-diagnostic-obd-system-check) in SELF-DIAGNOSTICS - DIESEL article in ENGINE PERFORMANCE. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) in SELF-DIAGNOSTICS - GASOLINE article in ENGINE PERFORMANCE.
  7. Disconnect each module one at a time while monitoring Class 2 circuit for a short. If a short is removed after a module is disconnected, replace module that is shorting circuit. Perform diagnostic system check for module that was shorting circuit. See the following. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. See «DIAGNOSTIC SYSTEM OPERATION CHECK - ANTI-THEFT»(/gmc/savana/i-1996-2002/remont/door-locks-anti-theft-systems/#anti-theft-system__diagnostic-system-operation-check-anti-theft) in ANTI-THEFT SYSTEMS article. See «DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/anti-locktraction-control/#anti-lock-brake-system__diagnostic-system-check) in ANTI-LOCK BRAKES article in BRAKES. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-controls-tests-wcodes-diesel__on-board-diagnostic-obd-system-check) in SELF-DIAGNOSTICS - DIESEL article in ENGINE PERFORMANCE. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) in SELF-DIAGNOSTICS - GASOLINE article in ENGINE PERFORMANCE.
  8. Repair open or high resistance in 840 circuit wire. (Scheme 14) Perform diagnostic system check for module that is not communicating. See the following. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. See «DIAGNOSTIC SYSTEM OPERATION CHECK - ANTI-THEFT»(/gmc/savana/i-1996-2002/remont/door-locks-anti-theft-systems/#anti-theft-system__diagnostic-system-operation-check-anti-theft) in ANTI-THEFT SYSTEMS article. See «DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/anti-locktraction-control/#anti-lock-brake-system__diagnostic-system-check) in ANTI-LOCK BRAKES article in BRAKES. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/testing-diagnostics/#engine-controls-tests-wcodes-diesel__on-board-diagnostic-obd-system-check) in SELF-DIAGNOSTICS - DIESEL article in ENGINE PERFORMANCE. See «ON-BOARD DIAGNOSTIC (OBD) SYSTEM CHECK»(ref-132811-S27457185922002013000000) in SELF-DIAGNOSTICS - GASOLINE article in ENGINE PERFORMANCE.

SCAN TOOL DOES NOT COMMUNICATE WITH UART DATA LINE

WARNINGVehicles are equipped with air bag supplemental restraint system. Before attempting any repairs involving steering column, instrument panel or related components, see SERVICE PRECAUTIONS and DISABLING & ACTIVATING AIR BAG SYSTEM in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.

The UART Serial Data Line is used for communication with the supplemental inflatable restraint Sensing and Diagnostic Module (SDM). The UART line relies on a 5-volt digital signal for the exchange of data between different control modules and to provide scan tool diagnostic data. When the ignition switch is in the RUN position and the UART line is at rest with no communication taking place, the voltage is approximately 5 volts. When data is transmitted the voltage is pulled to ground, approximately 0 volts. The scan tool may be used to retrieve, view, and clear Diagnostic Trouble Codes (DTC) stored in the SDM. The scan tool also uses the UART line to receive serial data from the SDM. A loss of UART communications would prevent the scan tool from communicating with the SDM during SIR system diagnosis.

  1. Perform SIR diagnostic system check. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. Go to next step.
  2. Ensure scan tool is functioning properly. If scan tool powers up, go to next step. If scan tool does not power up, see «SCAN TOOL INOPERATIVE/DOES NOT COMMUNICATE WITH COMPONENTS»(/gmc/savana/i-1996-2002/remont/communication-devices/#data-link-communications-system__scan-tool-inoperativedoes-not-communicate-with).
  3. Inspect for proper connection/terminal tension of scan tool to DLC terminal No. 9. (Scheme 13) If there is no fault with connector, go to next step. If there is any fault with connector, repair and perform SIR diagnostic system check. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.
  4. Carefully disconnect SDM. Check for poor connection/terminal tension at SDM terminal No. 5. (Scheme 14) If there is no fault with connector, go to next step. If there is any fault with connector, repair and perform SIR diagnostic system check. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.
  5. Test for an open in 800 circuit wire between DLC and SDM connector. (Scheme 14) If there is no fault with the wire, go to next step. If there is any fault with the wire, repair and perform SIR diagnostic system check. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.
  6. Test for a short to ground in 800 circuit wire between DLC and SDM connector. (Scheme 14) If there is no fault with the wire, go to next step. If there is any fault with the wire, repair and perform SIR diagnostic system check. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.
  7. Test for a short to voltage in 800 circuit between DLC and SDM connector. (Scheme 14) If there is no fault with the wire, go to next step. If there is any fault with the wire, repair and perform SIR diagnostic system check. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.
  8. Turn ignition switch to OFF. Replace Inflatable Restraint Sensing and Diagnostic Module. See «SENSING & DIAGNOSTIC MODULE (SDM)»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS. Perform SIR diagnostic system check. See «SIR DIAGNOSTIC SYSTEM CHECK»(/gmc/savana/i-1996-2002/remont/airbag/#supplemental-inflatable-restraint-system__sir-diagnostic-system-check) in AIR BAG RESTRAINT SYSTEM article in RESTRAINTS.

Scheme 13

Scheme 13: CONNECTOR IDENTIFICATION
Scheme 13: CONNECTOR IDENTIFICATION

Scheme 14

Scheme 14: WIRING DIAGRAMS
Scheme 14: WIRING DIAGRAMS