Document ID# 1229565
1998 Saturn SL2/SC2/SW2 		 

SIR Diagnostic System Check Chart B


Object Number: 1207173 Size: MF
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Circuit Description

When the ignition switch is first turned On, "Ignition 1" voltage is applied to the AIR BAG telltale lamp which is connected to the "AIR BAG" terminal A7 of the SDM. The AIR BAG fuse applies system voltage to the "Ignition 1" input terminal A10 of the SDM. The SDM responds by flashing the AIR BAG telltale lamp seven times by providing a ground. If "Ignition 1" is outside the normal operating voltage range (approximately 9 VDC to 16 VDC), the AIR BAG telltale lamp will come On solid with no diagnostic trouble code set.

Diagnostic AIDS

A shorting bar in the harness at the SDM ensures that the AIR BAG telltale lamp will come On steady if the connector is not fully seated.

If the SDM harness connector, strain relief or the CPA are installed incorrectly or not installed the "AIR BAG" telltale lamp will be on steady.

Test Description

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

  1. This step verifies the AIR BAG fuse.

    2.

  2. This step verifies that the shorting bar at terminals A7 and A6 is open when the connector and CPA are fully engaged at the SDM.

    3.

  3. This step checks to see if the AIR BAG fuse will open again.

    4.

  4. This step checks to see if the malfunction is due to the starting and charging system or the SIR system.

    5.

  5. This step checks for terminal tightness and continuity to ground from the SDM.

    6.

  6. This step check to see if the air bag fuse will open again.

    7.

  7. This step verifies that the ignition voltage is present at the SDM.

    8.

  8. This step verifies that the AIR BAG warning lamp does not turn On with the shorting bar at the SDM harness connector.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - SIR?

Go to Step 2

Go to SIR Diagnostic System Check

2

  1. Turn OFF the ignition.
  2. Remove and inspect AIR BAG fuse.

Is fuse good?

Go to Step 3

Go to Step 4

3

Inspect the SDM harness connector.

Is the connector and yellow strain relief securely connected to the SDM?

Go to Step 5

Go to Step 6

4

  1. Replace AIR BAG fuse.
  2. Turn ON the ignition, wait 10 seconds, turn OFF the ignition.
  3. Remove and inspect AIR BAG fuse.

Is fuse good?

Go to Step 9

Go to Step 8

5

  1. Turn ON the ignition.
  2. Disconnect the SDM.
  3. Measure voltage at terminal A10 and a known good ground.

Is voltage greater than 16 volts or less than 9 volts?

Go to "Starting and Charging" section in Engine Electrical

Go to Step 6

6

  1. Turn Off the ignition.
  2. Check for proper connection to SDM at terminal A10 and A6.
  3. If ok, then measure resistance from SDM harness connector from terminal A6 to ground.

Is resistance one ohm or less?

Go to Step 10

Go to Step 11

7
  1. Properly connect SDM harness connector to SDM.
  2. Install AIR BAG fuse.
  3. Go to Step 16

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8

  1. Disconnect SDM.
  2. Replace AIR BAG fuse.
  3. Turn ON ignition, wait 10 seconds, then turn Off ignition.
  4. Remove and inspect AIR BAG fuse.

Is fuse good?

Go to Step 13

Go to Step 12

9
  1. Install AIR BAG fuse.
  2. Go to Step 16

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10

  1. Install AIR BAG fuse.
  2. Disconnect driver and passenger inflator modules, yellow two-way connectors located at the base of steering column and under the instrument panel top cover.
  3. Turn On ignition.
  4. Measure voltage on SDM harness connector from terminal A10 to terminal A6 (ground).

Is voltage one volt or less?

Go to Step 14

Go to Step 15

11
  1. Repair open in circuit 1751.
  2. Reconnect SDM.
  3. Install AIR BAG fuse.
  4. Go to step 18

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12
  1. Repair short to ground in circuit 1139.
  2. Reconnect SDM.
  3. Replace AIR BAG fuse.
  4. Go to Step 18

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13
  1. Replace SDM
  2. Install AIR BAG fuse.
  3. Go to Step 18

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14
  1. Turn Off ignition.
  2. Repair open in circuit 1139.
  3. Go to step 18

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15

  1. Turn OFF ignition.
  2. Connect SIR driver/passenger load tool using SDM dummy connector to SDM harness connector.
  3. Turn On ignition.

Does AIR BAG telltale lamp come on?

Go to Step 17

Go to Step 16

16
  1. Replace SDM. Refer to Sensing and Diagnostic Module (SDM).
  2. Go to Step 17

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17
  1. Repair short from circuit 358 to ground.
  2. Go to Step 17

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18
  1. Reconnect all SIR system components.
  2. Ensure all components are properly mounted.
  3. Repeat SIR Diagnostic System Check.

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  Document ID# 1229565
1998 Saturn SL2/SC2/SW2