Supplemental Inflatable Restraint System: Overview Saturn ION I

SIR Schematic Icons

SIR Schematic Icons Icon Icon Definition CAUTION: When performing service on or near the SIR components or the SIR wiring, the SIR system must be disabled. Refer to SIR Disabling and Enabling Zones. Failure to observe the correct procedure could cause deployment of the SIR components, personal injury, or unnecessary SIR system repairs. IMPORTANT: In order to prevent accidental deployment, the shorting bars close in order to short the connectors when the connectors are separated. Twisted-pair wires provide an effective shield that helps protect sensitive electronic components from electrical interference. If the wires were covered with shielding, install new shielding. In order to prevent electrical interference from degrading the performance of the connected components, you must maintain the proper specification when making any repairs to the twisted-pair wires shown : The wires must be twisted a minimum of 9 turns per 31 cm (12 in) as measured anywhere along the length of the wires The outside diameter of the twisted wires must not exceed 6.0 mm (0.25 in)

Scheme 1

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

SIR Zone Identification Views (Coupe)

The SIR Zone Identification Views shown below illustrate the approximate location of all SIR components available for the vehicle. This will assist in determining the appropriate SIR Disabling and Enabling Zones for a given service procedure, refer to SIR Disabling and Enabling Zones .

Scheme 12

SIR Zone Identification Views (Sedan)

The SIR Zone Identification Views shown below illustrate the approximate location of all SIR components available for the vehicle. This will assist in determining the appropriate SIR Disabling and Enabling Zones for a given service procedure, refer to SIR Disabling and Enabling Zones .

Scheme 13

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 4: This step tests to see if the malfunction is caused by the I/P.
2. 6: This step tests to see what DTCs are present. If DTC B0012 or B0016 is present, test for a short between the I/P high and low circuits in stage 1 or stage 2. If DTC B0013 or B0017 is present, test the I/P high and low circuits for an open and for high resistance in stage 1 or stage 2. If DTC B0014 or B0018 is present, test the I/P high and low circuits for a short to ground and for a short to voltage in stage 1 or stage 2.

DTC B0012, B0013, B0014, B0016, B0017, or B0018

Scheme 14

The numbers below refer to the step numbers on the diagnostic table.

1. 5: This step tests to see if the malfunction is caused by the steering wheel module or by the steering wheel module coil.
2. 7: This step tests to see what DTCs are present. If DTC B0022 or B0042 is present, test for a short between the steering wheel module high and low circuits in stage 1 or stage 2. If DTC B0024 or B0043 is present, test the steering wheel module high and low circuits for an open and for high resistance in stage 1 or stage 2. If DTC B0026 or B0044 is present, test the steering wheel module high and low circuits for an open and for high resistance in stage 1 or stage 2.

DTC B0022, B0024, B0026, B0042, B0043, or B0044

Scheme 15

The numbers below refer to the step numbers on the diagnostic table.

1. 4: This step tests to see if the malfunction is caused by the roof rail module - right.
2. 6: This step tests to see what DTCs are present. If DTC B0028 is present, test for a short between the roof rail module - right high and low circuits. If DTC B0029 is present, test the roof rail module - right high and low circuits for an open and for high resistance. If DTC B0030 is present, test the roof rail module - right high and low circuits for a short to ground and for a short to voltage.

DTC B0028, B0029, or B0030

Scheme 16

The numbers below refer to the step numbers on the diagnostic table.

1. 4: This step tests to see if the malfunction is caused by the roof rail module - left.
2. 6: This step tests to see what DTCs are present. If DTC B0040 is present, test for a short between the roof rail module - left high and low circuits. If DTC B0041 is present, test the roof rail module - left high and low circuits for an open and for high resistance. If DTC B0045 is present, test the roof rail module - left high and low circuits for a short to ground and for a short to voltage.

DTC B0040, B0041, or B0045

The numbers below refer to the step number on the diagnostic table.

1. 4: This step tests to see if the malfunction is caused by the seat belt pretensioner - RF.
2. 6: This step tests to see what DTCs are present. If DTC B0057 is present, test for a short between the seat belt pretensioner - RF high and low circuits. If DTC B0058 is present, test the seat belt pretensioner - RF high and low circuits for an open and for high resistance. If DTC B0059 is present, test the seat belt pretensioner - RF high and low circuits for a short to ground and for a short to voltage.

DTC B0057, B0058, or B0059

Scheme 17

The numbers below refer to the step numbers on the diagnostic table.

1. 4: This step tests to see if the malfunction is caused by the seat belt pretensioner - LF.
2. 6: This step tests to see what DTCs are present. If DTC B0064 is present, test for a short between the seat belt pretensioner - LF high and low circuits. If DTC B0065 is present, test the seat belt pretensioner - LF high and low circuits for an open and for high resistance. If DTC B0066 is present, test the seat belt pretensioner - LF high and low circuits for a short to ground and for a short to voltage.

DTC B0064, B0065, or B0066

Scheme 18

The numbers below refer to the step numbers on the diagnostic table.

1. 7: This step tests the SIS signal and SIS voltage circuits for an open or high resistance.
2. 8: This step tests between the SIS signal and SIS voltage circuits for continuity.
3. 9: This step tests the SIS signal and SIS voltage circuits for a short to voltage.

DTC B0077, B0078, B0079, B0080, B0081, or B0082

The numbers below refer to the step numbers on the diagnostic table.

1. 2: Tests to see if the correct VIN is programmed in the ECM.
2. 4: Tests to see if the BCM has been replaced.
3. 5: Tests to see if the correct VIN is programmed in the BCM.

DTC B1001

Symptoms - SIR

1. Perform the «Diagnostic System Check - Vehicle»(ref-196940-S27536559152005101000000) in Vehicle DTC Information, before using the symptom tables in order to verify that all of the following are true: There are no diagnostic trouble codes (DTCs) set. The inflatable restraint sensing and diagnostic module (SDM) can communicate via the serial data link.
2. Review the SIR system description and operation in order to familiarize yourself with the system functions. Refer to «SIR System Description and Operation»(ref-196951-S19958267882005101000000) .

SIR System Overview

The supplemental inflatable restraint (SIR) system supplements the protection offered by the occupants Seat Belt System (2). The SIR system may contain several inflator modules located throughout the vehicle, i.e. steering wheel module (1), instrument panel (I/P) module (1), or roof rail modules. In addition to inflator modules, the vehicle may contain seat belt pretensioners that tighten the seat belt in the event of a collision, thus reducing the distance between the occupant and the seat belt when an inflator module is deployed. Each inflator module has a deployment loop that is controlled by the sensing and diagnostic module (SDM) mounted inside the vehicle. The SDM determines the severity of a collision with the assistance of various sensor inputs located at strategic points on the vehicle. When the SDM detects a collision, it will process the information provided by the sensors to further support air bag or pretensioner deployment. The SDM will deploy the frontal air bags and pretensioners if it detects a collision of sufficient force. If the force of the impact is not sufficient to warrant inflator module deployment, the SDM may still deploy the seat belt pretensioners. The SDM performs continuous diagnostic monitoring of the SIR system electrical components. Upon detection of a circuit malfunction, the SDM will set a DTC and inform the driver by turning the AIR BAG indicator ON. The steering column (1) and knee bolsters (3) are designed to absorb energy and compress during frontal collisions in order to limit leg movement and decrease the chance of injury to the driver and passenger.

Scheme 19

Frontal SIR System Description

The frontal supplemental inflatable restraint (SIR) system consists of the following components

1. AIR BAG indicator located in the instrument panel cluster (IPC)
2. Driver and front passenger knee bolsters
3. Inflatable restraint sensing and diagnostic module (SDM)
4. Inflatable restraint instrument panel (I/P) module
5. Inflatable restraint steering wheel module
6. Inflatable restraint steering wheel module coil
7. Inflatable restraint seat belt retractor pretensioners
8. Inflatable restraint wiring harnesses
9. Steering wheel and column

A frontal collision of sufficient force will deploy the frontal air bags and/or pretensioners. The sensing and diagnostic module (SDM) contains a sensing device that converts vehicle velocity changes to an electrical signal. The SDM compares these signals to values stored in memory. If the signals exceed a stored value, the SDM will determine the severity of the impact and either cause current to flow through the frontal deployment loops deploying the frontal air bags and pretensioners, or it will deploy the pretensioners only. The SDM, I/P module, steering wheel module, steering wheel module coil, seat belt retractor pretensioners, and the connecting wires make up the frontal deployment loops. The SDM continuously monitors the deployment loops for malfunctions and turns the AIR BAG indicator ON if a fault is detected.

Side SIR System Description

The side supplemental inflatable restraint (SIR) system consists of the following components

1. AIR BAG indicator located in the instrument panel cluster (IPC)
2. Inflatable restraint sensing and diagnostic module (SDM)
3. Inflatable restraint side impact sensors (SIS) (left/right)
4. Inflatable restraint roof rail modules (left/right)
5. Inflatable restraint wiring harnesses