Chevrolet B0074 Code: Passenger Presence Sensor Fault
The pressure sensor mat inside the passenger seat cushion is giving bad or no readings.
Stop driving
The vehicle drives normally, but the passenger airbag may be turned off or misclassify whoever sits there. Keep the front seat empty when you can, never seat a child there, and get the SRS repaired.
Safety first · Consult a professional
- Airbag (SRS) circuits must only be serviced by a professional. Never probe airbag connectors — accidental deployment causes serious injury.
At a glance
Severity: High
- Meaning
- Passenger Presence Sensor Fault
- System
- Body Systems · Body
- Safe to drive?
- With caution
- Typical repair cost
- $0–$1,200
- DIY difficulty
- Professional only
In the passenger presence system used on Chevrolets such as the Impala, Silverado, Tahoe, Suburban and Cobalt, the actual sensing is done by a thin pressure-sensing mat (or on some older designs a fluid bladder) built into the passenger seat cushion. Its readings go through a short flat pigtail to the presence module under the seat, which classifies the occupant so the airbag module can arm or suppress the passenger airbag. B0074 means the sensor itself is out of range, inconsistent or not connected properly. Because the mat lives in the foam, damage from kneeling, heavy loads, sharp objects or a pinched sensor tail is far more common than an electronic failure, and GM has told technicians on some models to check the sensor terminals and harness routing before replacing anything.
How to read B0074
- B Body
- 0 Generic (SAE)
- 0 Body Systems
- 74 Specific fault
Symptoms
- Airbag warning light or SERVICE AIRBAG message
- PASSENGER AIRBAG OFF lit even with an adult seated
- Airbag status changes as the passenger shifts or leans
- Fault appeared after someone stood or knelt on the seat, or after heavy cargo sat on it
- Fault started after a seat cover, heated pad or cushion was added
- B0081 stored alongside B0074
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Sensor mat or bladder in the cushion cracked, creased or damaged by kneeling, tools or cargo
- Sensor tail doubled over or pinched between the seat frame and foam, or loose spade terminals at the mat
- Aftermarket seat cover, seat heater pad or object under the cover loading the sensor
- Seat frame or suspension wire bent, pressing on the mat with the seat empty
- Empty-seat PPS setup not done after seat or cover service
- Presence module misreading a good sensor
Diagnosis step by step
Remove anything on or under the seat
Take off aftermarket covers, cushions and heated pads and clear objects from under the seat and the seat pocket. Restart the vehicle with the seat empty and watch whether the airbag light and passenger indicator behave normally.
Tools: Flashlight
Read codes and live PPS data
A GM-capable scan tool shows B0074 with its symptom byte and the presence system's live readings. With the seat empty, the reading should sit at its empty-seat value; pressing on the cushion by hand should change it smoothly, while a stuck or jumping value points to the mat or its connection.
Tools: OBD-II scanner
Check the seat for physical damage
Look for a sagging, torn or creased cushion and a bent seat frame, and check that the seat moves through its full travel without the harness going tight. This can be done without touching any SRS connector.
Tools: Flashlight
Inspect the sensor tail and terminals
Reaching the mat means removing the seat and pulling the cushion cover, which is SRS work for a technician with the battery disconnected. They check that the sensor tail isn't folded or trapped and that its terminals are fully seated and insulated.
Tools: Screwdriver, Flashlight
Reroute or replace, then run PPS setup
If the tail was trapped, rerouting it with slack and redoing the connection often fixes it. A damaged mat is usually replaced with the cushion or as a kit; either way the empty-seat PPS setup must be completed afterward.
Tools: OBD-II scanner
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Remove aftermarket cover and clear codes | No | $0–$100 |
| Re-seat sensor terminals and reroute sensor tail, PPS setup | No | $150–$350 |
| Replace passenger presence sensor mat or cushion assembly | No | $400–$950 |
| Replace matched sensor, module and cushion kit | No | $550–$1,200 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Emissions / smog test impact
Depends
B0074 has no effect on an OBD emissions test. A state safety inspection may fail the vehicle if the airbag warning light stays on.
Frequently asked questions
What's the difference between B0074 and B0081?
B0074 points at the sensor in the seat cushion, while B0081 is a fault reported for the presence module under the seat. When both are stored, the sensor or its connection is usually the root cause and the module is often fine.
Can a seat cover really cause this?
Yes. Tight covers, beaded cushions and add-on heating pads press on the sensing mat or change how weight spreads across it. Remove them before paying for diagnosis.
Can the mat be repaired?
No. A damaged mat or bladder is replaced, not patched, because its readings are part of how the airbag decides to deploy. What can often be fixed is the sensor tail's routing and its terminals.
Why does the passenger airbag light change when my passenger moves?
A weak or intermittent sensor produces readings that swing around the threshold between classifications. That instability is exactly what B0074 flags, and it's a reason not to rely on the passenger airbag until it's repaired.
Sources
- Manufacturer public service information (cross-checked)
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