Front End Sensor 3 Erratic
Table of contents
B0091 CADILLAC Possible Causes
- Faulty Front End Sensor 3
- Front End Sensor 3 harness is open or shorted
- Front End Sensor 3 circuit poor electrical connection
- Faulty Inflatable Restraint Sensing and Diagnostic Module (SDM)
How do I fix code B0091 CADILLAC?
Check the “Possible Causes” listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector’s pins.
Tech Notes
- DTC B0091 00 Front End Sensor 3 No Additional Information (Center)
- DTC B0091 01 Front End Sensor 3 Short to Battery (Center)
- DTC B0091 02 Front End Sensor 3 Short to Ground (Center)
- DTC B0091 05 Front End Sensor 3 Short to Battery or Open (Center)
- DTC B0091 0F Front End Sensor 3 Erratic (Center)
- DTC B0091 39 Front End Sensor 3 Internal Electronic Failure (Center)
- DTC B0091 3A Front End Sensor 3 Incorrect Component Installed (Center)
- DTC B0091 71 Front End Sensor 3 Invalid Serial Data Received (Center)
Cost of diagnosing the B0091 CADILLAC code
The cost of diagnosing the B0091 CADILLAC code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle’s make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.
Possible Symptoms
- Air Bag Warning Light ON
B0091 CADILLAC Description
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.