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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1999 🢒 Eldorado 🢒 Restraints 🢒 SIR 🢒 DTC B1116 Passenger Deploy. Loop Resistance Low

Object Number: 381183 Size: MF
SIR Components
SIR Schematics DeVille
SIR Schematics Eldorado
SIR Caution
Handling ESD Sensitive Parts Notice
SIR Schematic Icons

Circuit Description

When you first turn the ignition switch to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within the module. Next the SDM measures Ignition Positive Voltage and the deployment loop voltages to make sure they are within their respective normal voltage ranges. Then the SDM proceeds with the RESISTANCE MEASUREMENT test. During one portion of the RESISTANCE MEASUREMENT test, the SDM does the following:

    • Grounds the PASSENGER FRONTAL LOW terminal 8 through an internal current sink.
    • Connects the PASSENGER FRONTAL HIGH terminal 7 to an internal constant current source. This current produces proportional voltage drops in the deployment loop.
    • Measures the voltage difference between PASSENGER FRONTAL HIGH and PASSENGER FRONTAL LOW.
    • Calculates the resistance of the passenger frontal deployment loop using the measured voltage.

Conditions for Setting the DTC
    • The driver and passenger frontal deployment loops are not open.
    • The driver and passenger frontal deployment loops are not shorted to voltage.
    • The driver and passenger frontal deployment loops are not shorted to ground.
    • The passenger frontal deployment loop resistance is less than 1.4 ohms. The passenger frontal deployment loop consists of the following components:
       - Inflatable restraint IP module.
       - Harness wiring of CKT 1403.
       - Harness wiring of CKT 1404.
       - Connector terminal contact.

The RESISTANCE MEASUREMENT test checks for this malfunction. This test only occurs once each ignition cycle when Ignition Positive Voltage is within the normal operating voltage range.

Action Taken When the DTC Sets
    • The SDM sets a diagnostic trouble code.
    • The SDM commands the instrument panel cluster (IPC) to turn ON the AIR BAG warning lamp.

Conditions for Clearing the MIL/DTC
    • Current DTC
        The resistance of the passenger frontal deployment loop is more than 1.4 ohms and the ignition switch is cycled.
    •  History DTC
       - You issue a scan tool CLEAR CODES command.
       - 250 malfunction free ignition cycles occur.

When you issue a scan tool CLEAR CODES command and the malfunction is still present, the DTC will not reappear until the next ignition cycle.

Diagnostic Aids

The following can cause an intermittent condition:

    • A short circuit between CKT 1403 and CKT 347.
    • A short circuit between CKT 1403 and CKT 348.
    • A short circuit between CKT 1403 and CKT 1404.
    • A malfunctioning shorting bar on the inflatable restraint IP module connector.

When measurements are requested in this table, use J 39200 Digital Multimeter with the correct terminal adapter from J 35616 Connector Test Adapter Kit. When a check for proper connection is requested, refer to Intermittents and Poor Connections . When a wire, connector or terminal repair is requested, use J-38125 Terminal Repair Kit and refer to Wiring Repair .

Test Description

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

  1. This test checks for a short from CKT 347 to CKT 1403.

    2.

  2. This test checks for proper contact or corrosion of the inflatable restraint IP module connector.

    3.

  3. This test isolates the malfunction to one side of the inflatable restraint IP module yellow 2-way connector.

    4.

  4. This test checks for a short from CKT 1403 to CKT 1404.

    5.

  5. This test checks for a short from CKT 1403 to CKT 348.

DTC B1116 Passenger Deployment Loop Resistance Low

Step

Action

Value(s)

Yes

No

1

Was the SIR Diagnostic System Check performed?

--

Go to Step 2

Go to SIR Diagnostic System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Connect a scan tool to the DLC.
  3. Turn the ignition switch to the RUN position.
  4. Request the SIR DTC display.

Is DTC B1122 also present?

--

Go to Step 3

Go to Step 4

3
  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint steering wheel and IP module yellow 2-way connectors at the base of the steering column and behind the IP compartment.
  3. Repair the short from CKT 347 to CKT 1403.

Have the repairs been completed?

--

Go to Step 11

--

4

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint IP module yellow 2-way connector behind the IP compartment.
  3. Reconnect the 2-way connector.
  4. Make sure that the CPA is properly installed.
  5. Turn the ignition switch to the RUN position.
  6. Using a scan tool, request the SIR DTC display.

Is DTC B 1116 set as a current DTC?

--

Go to Step 5

Go to Step 11

5

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint steering wheel and IP module yellow 2-way connectors at the base of the steering column and behind the IP compartment.
  3. Connect the J 38715-A SIR Driver/Passenger Load Tool to the harness connectors.
  4. Turn the ignition switch to the RUN position.
  5. Using a scan tool, request the SIR DTC display.

Is DTC B1116 set as a current DTC?

--

Go to Step 7

Go to Step 6

6

Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Have the repairs been completed?

--

Go to Step 11

--

7

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  3. Disconnect the J 38715-A .
  4. Using J 39200 DMM, measure the resistance between SDM harness connector terminals 7 and 8.

Is the resistance less than the specified value?

OL

Go to Step 8

Go to Step 9

8
  1. Turn the ignition switch to the OFF position.
  2. Repair the short from CKT 1403 to CKT 1404.

Have the repairs been completed?

--

Go to Step 11

--

9

Using J 39200 , measure the resistance between SDM harness connector terminals 8 and 9.

Is the resistance less than the specified value?

OL

Go to Step 10

Go to Sensing and Diagnostic Module Integrity Check

10

Repair the short from CKT 1403 to CKT 348.

Have the repairs been completed?

--

Go to Step 11

--

11

Reconnect all the SIR system components, make sure all the components are properly mounted.

Have all the SIR components been reconnected and properly mounted?

--

Go to Step 12

--

12

Clear the SIR DTCs.

Have all the SIR DTCs been cleared?

--

Go to SIR Diagnostic System Check

--