Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
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HOMESERVICE MANUALSCHEVROLET2008CHEVY EXPRESS G3500, VAN PASSENGER EXTENDEDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 501 (SUPPLEMENTAL INFLATABLE RESTRAINT SYSTEM)DIAGNOSTIC INFORMATION AND PROCEDURESDTC B0091CIRCUIT/SYSTEM TESTING
2008 Chevrolet Chevy Express G3500, Van Passenger Extended
Circuit/System Testing
2008 Chevrolet Chevy Express G3500, Van Passenger ExtendedSECTION Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2009 GMC Savana Special, 2009 GMC Savana Camper Special, 2009 GMC Savana, 2009 Chevrolet RV Cutaway, and 2009 Chevrolet Cutaway. However, it is still accessible from the selected car via links, so may be relevant.
- Front end sensor
- SDM module
- Front end sensor wiring harness connector
- SDM wiring harness connector
- Ignition OFF, disconnect the harness connector at the front end sensor and the SDM.
- Ignition ON, test for less than 1 volt between the front end sensor signal circuit terminal 2 and ground.
- If greater than the specified range, test the signal circuit for a short to voltage.
- Ignition ON, test for less than 1 volt between the front end sensor low reference circuit terminal 1 and ground.
- If greater than the specified range, test the low reference circuit for a short to voltage.
- Test for infinite resistance between the front end sensor signal circuit terminal 2 and ground.
- If less than the specified value, test the signal circuit for a short to ground.
- Test for infinite resistance between the front end sensor low reference circuit terminal 1 and ground.
- If less than the specified value, test the low reference circuit for a short to ground.
- Test for less than 1 ohm between the SDM signal circuit terminal 38 and the front end sensor circuit terminal 2 harness connector.
- If greater than the specified range, test the signal circuit for an open/high resistance.
- Test for less than 1 ohm between the SDM low reference circuit terminal 36 and the front end sensor circuit terminal 1 harness connector.
- If greater than the specified range, test the low reference circuit for an open/high resistance.
- If all circuits test normal, test or replace the front end sensor.
- Reconnect all SIR components. Ignition ON, verify the DTC is not set as current.
- If the DTC resets as current, replace the SDM.
IMPORTANT:
When removing the connectors, inspect for damage or corrosion. Damage or corrosion to the following requires repair or replacement of the affected component/connector:
RENDER: 1.0x
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.