Where are grounds for airbag sensors on a 2
009 Silverado 3500hd. I have replaced the front airbag sensor but still get code B0091-00.
sensor that was replaced per the code scanner , That's where you made your mistake . No code tell's you to replace a part without testing . Did you do factory trouble shooting per code diagnostic testing procedures ?
The inflatable restraint front end sensor utilizes a unidirectional 2-wire circuit. The front end sensor modulates current on the interface to send ID, state of health, and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). The SDM serves as a power source and a ground for the front end sensor. When the ignition is turned ON and input power from the SDM is first detected, the front end sensor responds by performing internal diagnostics and sending an ID to the SDM. The SDM considers the ID to be valid if the response time is less than 5 seconds. The front end sensor continually communicates status messages to the SDM, which determines if a fault is present in the front end sensor circuit. When a fault is detected, the SDM may reset the front end sensor up to 2 times by removing and reapplying power to it. If the fault is still present, the SDM will set a DTC.
B0091 00
• The front end sensor has been shorted to voltage, open, or shorted to ground.
• The front end sensor current has been above 23 mA for longer than 5 milliseconds.
• The SDM has not received a message from the front end sensor for more than 375 milliseconds.
Circuit/System Testing
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:
• 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.
10/28/2018 10:18:23 AM •
Chevrolet...
•
Answered
on Oct 28, 2018