GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Cobalt 🢒 Restraints 🢒 SIR 🢒 DTC B1325

Circuit Description

The inflatable restraint sensing and diagnostic module (SDM) monitors the battery positive voltage input from the battery. If the SDM detects this battery positive voltage circuit is above or below the threshold, then DTC B1325 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1325 Device Power 1 Circuit

DTC Symptom

DTC Symptom Descriptor

03

Voltage Below Threshold

07

Voltage Above Threshold

Conditions for Running the DTC

The voltage supplied to the body control module (BCM) is in the range of 9-16 volts.

Conditions for Setting the DTC

B1325 03

    • The SDM detects a system voltage below 9 volts.
    • This condition is present at least 10 seconds.

B1325 07

    • The SDM detects a system voltage above 16 volts.
    • This condition is present at least 10 seconds.

Action Taken When the DTC Sets
    • The SDM commands the AIR BAG indicator ON via GMLAN serial data.
    • The SDM stores DTC to memory.

Conditions for Clearing the DTC
    • A current DTC clears when the malfunction is no longer present.
    • A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

Step

Action

Values

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe the Battery Voltage Input parameters in the SIR input data list.

Is the Battery Voltage Input displayed on the scan tool within the specified range?

9-16 V

Go to Step 3

Go to Step 4

3

Is DTC B1325 set as a history DTC?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

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4
  1. Turn OFF the ignition.
  2. Disconnect the inflatable restraint sensing and diagnostic (SDM) connectors. Refer to Control Module References for replacement, setup, and programming.
  3. Inspect the SDM for corrosion or poor connections that may cause a malfunction in the battery positive voltage circuit. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 9

Go to Step 5

5
  1. Turn ON the ignition, with the engine OFF.
  2. Measure the voltage in the battery positive voltage circuit in the SDM harness connector and a ground.

Does the voltage measure within the specified value?

9-16 V

Go to Step 8

Go to Step 6

6
  1. Access the body control module (BCM). Refer to Control Module References for replacement, setup, and programming.
  2. Measure the voltage from the voltage side of the AIR BAG (BATT) fuse to a ground.

Does the voltage measure within the specified range?

9-16 V

Go to Step 7

Go to Charging System Test

7
  1. Turn OFF the ignition.
  2. Test the battery positive voltage circuit between the output side of the AIR BAG (BATT) fuse and the SDM harness connector for high or low resistance.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

8

Replace the SDM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 9

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9
  1. Connect all SIR and BCM components.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTCs as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK