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Home >> Chevy Truck >> 2013 >> Silverado 2500 2WD V8-6.0L (CNG) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> B Code Charts >> B0091

B0091




DTC B0091

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0091 00
- Center Front Impact Sensor

DTC B0091 0F
- Center Front Impact Sensor Erratic

DTC B0091 39
- Center Front Impact Sensor Internal Electronic Failure

DTC B0091 3A
- Center Front Impact Sensor Incorrect Component Installed

Diagnostic Fault Information






Circuit/System Description

The impact sensors are equipped on vehicles to supplement the supplemental inflatable restraint (SIR) system performance. The impact sensors are electronic and are not part of the deployment loops, but instead provide inputs to the inflatable restraint sensing and diagnostic module (SDM). The impact sensors can assist in determining the severity of some frontal and side collisions. The inflatable restraint sensing and diagnostic module uses the input from the impact sensors to assist in determining the severity of a collision further supporting air bag deployment. If the inflatable restraint sensing and diagnostic module determines a deployment is warranted, the inflatable restraint sensing and diagnostic module will cause current to flow through the deployment loops deploying the appropriate air bags. The center front impact sensor and side impact sensors utilize a bidirectional 2-wire circuit. The sensors modulate current on the interface to send identification, state of health, and deployment commands to the inflatable restraint sensing and diagnostic module. The inflatable restraint sensing and diagnostic module serves as a power source and a ground for the sensors. When the ignition is turned ON and input power from the inflatable restraint sensing and diagnostic module is first detected, the sensors respond by performing internal diagnostics and sending an identification to the inflatable restraint sensing and diagnostic module. The inflatable restraint sensing and diagnostic module considers the identification to be valid if the response time is less than 5 seconds. The sensors continually communicate status messages to the inflatable restraint sensing and diagnostic module, which determines if a fault is present in the sensor circuit. When a fault is detected, the inflatable restraint sensing and diagnostic module may reset the sensors up to 2 times by removing and reapplying power to it. If the fault is still present, the inflatable restraint sensing and diagnostic module will set a DTC.

Conditions for Running the DTC

Ignition voltage is between 9-16 V.

Conditions for Setting the DTC

B0091 00

* The front impact sensor has an open, been shorted to ground, or been shorted to voltage.

* The center front impact sensor current is greater than 23 mA for greater than 5 milliseconds.

B0091 0F

The inflatable restraint sensing and diagnostic module has received erratic messages from the inflatable restraint front end sensor.

B0091 39

* The inflatable restraint sensing and diagnostic module has received a Not OK (NOK) message from the inflatable restraint front end sensor.

* The inflatable restraint sensing and diagnostic module has not received a message.

B0091 3A

* The inflatable restraint sensing and diagnostic module has received identification message from the center front impact sensor which does not match the identification stored in the inflatable restraint sensing and diagnostic module memory.

* The inflatable restraint sensing and diagnostic module has reset the center front impact sensor twice without detecting the correct identification message.

Action Taken When the DTC Sets

* The inflatable restraint sensing and diagnostic module requests the instrument panel cluster to illuminate the AIR BAG indicator.

* The SIR system is disabled and no deployments are allowed.

Conditions for Clearing the DTC

* The condition for setting the DTC no longer exists.

* A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

SIR Schematics [1][2]Air Bag Systems

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (M30)

Description and Operation

SIR System Description and Operation Description and Operation

Electrical Information Reference

* Circuit Testing Circuit Testing

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

* Connector Repairs Connector Repairs

Scan Tool Reference

Control Module References Control Module References for scan tool information

Circuit/System Verification

Note:

* Refer to SIR Service Precautions Technician Safety Information.

* Inspect all terminals for damage or corrosion when disconnecting connectors. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

- Front impact sensor

- Side impact sensor

- Inflatable restraint sensing and diagnostic module

- Front impact sensor wiring harness connector

- Side impact sensor wiring harness connector

- Inflatable restraint sensing and diagnostic module wiring harness connector

* The connector and connector position assurance (CPA) may seat independent of each other. Both the connector and CPA should seat with an audible and/or tactile click. The CPA isolates the shorting-bars within the connector allowing the deployment circuit to operate properly. Replace any CPA that is damaged or missing.

* If the condition is intermittent or cannot be duplicated, disconnect the connectors and add dielectric grease / lubricant (Nyogel 760G or equivalent, meeting GM specification 9986087). This procedure will correct the high resistance condition due to terminal fretting corrosion.

1. Verify DTC B0091 3A or B0091 39 is not set as current.

• If DTC B0091 3A or B0091 39 is set as current
Replace the center front impact sensor.

• If DTC B0091 3A or B0091 39 is not set as current

2. Verify DTC B0091 00 or DTC B0091 0F is not set as current.

• If DTC DTC B0091 00 or DTC B0091 0F is set as current
Refer to Circuit/System Testing.

• If DTC DTC B0091 00 or DTC B0091 0F is not set as current

3. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the inflatable restraint front end sensor. It may take up to 2 minutes for all vehicle systems to power down.

2. Test for less than 10 ohms between the low reference circuit terminal 2 and ground.

• If 10 ohms or greater

1. Ignition OFF, disconnect the X2 harness connector at the inflatable restraint sensing and diagnostic module.

2. Test for less than 2 ohms in the low reference circuit end to end.

• If 2 ohms or greater, repair the open/high resistance in the circuit.

• If less than 2 ohms, replace the inflatable restraint sensing and diagnostic module.

• If less than 10 ohms

3. Ignition ON.

4. Test for less than 11 V between the signal circuit terminal 1 and ground.

• If 11 V or greater

1. Ignition OFF, disconnect the X2 harness connector at the inflatable restraint sensing and diagnostic module, ignition ON.

2. Test for less than 1 V between the signal circuit terminal 1 and ground.

• If 1 V or greater, repair the short to voltage on the circuit.

• If less than 1 V, replace the inflatable restraint sensing and diagnostic module.

• If less than 11 V

5. Ignition OFF.

6. Test for greater than 50k ohms between the signal circuit terminal 1 and ground.

• If 50k ohms or less

1. Disconnect the X2 harness connector at the inflatable restraint sensing and diagnostic module.

2. Test for infinite resistance between the signal circuit and ground.

• If less than infinite resistance, repair the short to ground on the circuit.

• If infinite resistance, replace the inflatable restraint sensing and diagnostic module.

• If greater than 50k ohms

7. Disconnect the X2 harness connector at the inflatable restraint sensing and diagnostic module.

8. Test for less than 2 ohms between the inflatable restraint front end sensor signal circuit terminal 1 and the inflatable restraint sensing and diagnostic module circuit terminal 23 X2.

• If 2 ohms or greater
Repair the open/high resistance in the circuit.

• If less than 2 ohms

9. Ignition OFF, connect all harness connectors, press in the CPA (if equipped) until an audible and/or tactile click is heard.

10. Ignition ON, clear DTCs.

11. Verify the DTC does not set while operating the vehicle under the conditions for running the DTC.

• If the DTC sets

1. Replace the inflatable restraint front end sensor.

2. Verify the DTC does not set while operating the vehicle under the conditions for running the DTC.

• If the DTC sets, replace the inflatable restraint sensing and diagnostic module.

• If the DTC does not set

3. All OK.

• If the DTC does not set

12. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification Verification Tests after completing the repair.

* Inflatable Restraint Front End Sensor Replacement (1500)

* Control Module References Control Module References for inflatable restraint sensing and diagnostic module replacement, programming and setup

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