GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 1999 🢒 S/T Isuzu - 4WD 🢒 DTC 🢒 DTC B1025 Driver Deployment Loop Short to Voltage

Object Number: 407417 Size: SF
Cell 47: Power, Ground, DLC and Sensors
Handling ESD Sensitive Parts Notice
SRS Service Precautions
Cell 47: Seat Belt Switch, Steering Wheel and IP Module
SRS Components

Circuit Description

When you first turn the ignition switch to the RUN position, the supplemental restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within the SDM. Upon passing these tests, the following circuits are measured in order to ensure that they are within their respective normal voltage ranges:

    • IGNITION 1
    • 23 VLR
    • Deployment loop voltages

The SDM monitors the voltages at DRIVER SIDE LOW terminal 3 and PASSENGER SIDE LOW terminal 4 to detect shorts to B+ in the inflator module circuits.

Conditions for Setting the DTC
    • The voltage at PASSENGER SIDE LOW terminal 4 is less than 4.8 volts.
    • The voltage at DRIVER SIDE LOW terminal 3 is more than 4.8 volts for 500 milliseconds.

The CONTINUOUS MONITORING test inspects for this DTC. This test occurs when IGNITION 1 is within the normal operating voltage range.

Action Taken When the DTC Sets
    • The SDM sets a diagnostic trouble code.
    • The SDM turns the AIR BAG warning lamp to the ON position.

Conditions for Clearing the DTC
    • Current DTC-The voltage at DRIVER SIDE LOW terminal 3 is less than 4.8 volts for 500 milliseconds.
    • History DTC
       - You issue a scan tool CLEAR CODES command.
       - After 250 malfunction free ignition cycles have occurred.

Diagnostic Aids

A short to B+ in the supplemental restraint steering wheel module circuit may cause an intermittent condition. Inspect CKT 347 and CKT 348 carefully for cutting or chafing. The diagnostic table directs the technician to note the entry value of DRIVER SENSELO. Comparing the value of DRIVER SENSELO may be helpful in determining if an intermittent condition exists.

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 an inspection 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 determines the driver side low voltage which is measuredby the supplemental restraint sensing and diagnostic module (SDM).

    2.

  2. This test isolates the malfunction to one side of the supplemental restraint steering wheel module coil yellow 2-way connector.

    3.

  3. This test determines whether the malfunction is due to the supplemental restraint steering wheel module or the module coil.

    4.

  4. This test determines whether the malfunction is in CKT 347.

    5.

  5. This test determines whether the malfunction is in CKT 348.

DTC B1025 -- Driver Deployment Loop Short to Voltage

Step

Action

Value(s)

Yes

No

1

Was the SRS Diagnostic System Check performed?

--

Go to Step 2

Go to SRS Diagnostic System Check

2

  1. Turn the ignition switch to the OFF position.
  2. Connect the Scan Tool to the DLC.
  3. Turn the ignition switch to the RUN position.
  4. Request the SRS data list display.
  5. Read and record on the repair order the driver side low voltage DRIVER SENSELO.

Has the DRIVER SENSELO been read and recorded on the repair order?

--

Go to Step 3

--

3

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the supplemental restraint steering wheel yellow 2-way connector at the base of the steering column and the IP module yellow 2-way connector located behind the glove box.
  3. Connect J 38715-A SRS Driver/Passenger Load Tool to the harness connectors.
  4. Turn the ignition switch to the RUN position.
  5. Using the Scan Tool , request the SRS data list display.
  6. Read the driver side low voltage DRIVER SENSELO.

Is DRIVER SENSELO more than the specified value?

4.8 V

Go to Step 7

Go to Step 4

4

  1. Turn the ignition switch to the OFF position.
  2. Remove the supplemental restraint steering wheel module. Refer to Supplemental Restraint Steering Wheel Module Replacement .
  3. Disconnect J 38715-A from the driver 2-way harness connector.
  4. Connect the driver 2-way connector.
  5. Connect J 38715-A to the upper supplemental restraint steering wheel module connector.
  6. Turn the ignition switch to the RUN position.
  7. Using the Scan Tool , request the SRS data list display.
  8. Read the driver side low voltage DRIVER SENSELO.

Is DRIVER SENSELO more than the specified value?

4.8 V

Go to Step 6

Go to Step 5

5
  1. Turn the ignition switch to the OFF position.
  2. Replace the supplemental restraint steering wheel module. Refer to Supplemental Restraint Steering Wheel Module Replacement .

Is the repair complete?

--

Go to Step 11

--

6
  1. Turn the ignition switch to the OFF position.
  2. Remove the supplemental restraint steering wheel module coil. Refer to Supplemental Restraint Steering Wheel Module Coil Replacement .
  3. Inspect the coil and the wires for damage.
  4. Replace the supplemental restraint steering wheel module coil. Refer to Supplemental Restraint Steering Wheel Module Coil Replacement .

Is the repair complete?

--

Go to Step 11

--

7

  1. Turn the ignition switch to the OFF position.
  2. Disconnect the SDM. Refer to Supplemental Restraint Sensing and Diagnostic Module Replacement .
  3. Disconnect the J 38715-A .
  4. Turn the ignition switch to the RUN position.
  5. Measure the voltage on the SDM harness connector from terminal 2 to terminal 6 to gorund.

Is the measured voltage less than the specified value?

1.0 V

Go to Step 9

Go to Step 8

8
  1. Turn the ignition switch to the OFF position.
  2. Repair a short to B+ condition in CKT 347.

Is the repair complete?

--

Go to Step 11

--

9

Measure the voltage on the SDM harness connector from terminal 3 to terminal 6 to gorund.

Is the measured voltage less than the specified value?

1.0 V

Go to Sensing and Diagnostic Module Integrity Check

Go to Step 10

10
  1. Turn the ignition switch to the OFF position.
  2. Repair a short to B+ condition in CKT 348.

Is the repair complete?

--

Go to Step 11

--

11
  1. Reconnect all the SRS components.
  2. Ensure all the components are properly mounted.

Have all of the SRS components been reconnected and properly mounted?

--

Go to Step 12

--

12

Clear all the SRS DTCs.

Have all the SRS DTCs been cleared?

--

Go to SRS Diagnostic System Check

--