U0170: Lost Communication With Restraints System Sensor A
A generic network and communication trouble code, same meaning on every brand.
Yes - but a silent impact sensor means the side airbags may not know about a crash on that side. Same rule as the rest of the family: drive if you must, repair without delay.
Symptoms
- Airbag warning light
- Code names a restraint sensor rather than the module
- May come and go with weather or door slams
- No driving symptoms
Likely causes, most common first
- Side impact satellite sensor failed
- Connector corrosion in door or pillar
- Wiring damaged where it flexes into the door
- Sensor mounting area disturbed by body repair
Read U0170 yourself before paying for diagnosis
A basic Bluetooth OBD-II scanner ($20-40) plugs into the port under the dashboard and shows this code with live sensor data on your phone - useful both for confirming the fix and for talking to a shop from an informed position.
What is going on and how it gets diagnosed
U0170 says the airbag computer lost contact with one of its remote impact sensors - the small accelerometers in doors, pillars and rockers that give side airbags their few milliseconds of warning. Without its sensor, the module may deploy late or not at all for impacts on that side, which is why the light comes on for what sounds like a minor telemetry issue.
These sensors live in the wettest, most-slammed parts of the body, and their wiring flexes with every door swing - so intermittent versions of this code that follow rain or cold snaps are usually connectors and harnesses, not sensors. One history question matters: bodywork. A door skin or pillar repair that moved the sensor, or replaced metal around it, can leave it mounted in a way that reads wrong, and the code is the only symptom you get.
Repair options and cost
Typical US independent-shop ranges, parts and labor. Dealers run higher; regional labor rates vary.
Owner reports mentioning U0170
“Car went crazy one day while behind the wheel everything malfunctioned then car shut off and won't start again. I could of easily got into an accident had there been any other vehicles around. Kids were scared. Codes come up as U0100,U0140,U0101,C0242,B0081-0F,B0081-71,B1370-01,B1370-06,U0155-00,U0170-00,P0856-00.”2008 Cadillac CTS · Jul 2023
“Keep getting air bag light on code u0170 and b0081 seems like this is a big safety problem with the pontiac g8 needs a recall on this problem and replaced the rear ABS sensors and still have the issue with it not working and replaced them 2 times with new sensors”2008 Pontiac G8 · Oct 2019 · 104,000 mi
“Passenger seat does not register a person sitting in it to activate air bag system. Codes retrieved: u0170 and b0081. Odometer: 86,000”2008 Pontiac G8 · Nov 2018 · 86,000 mi
Show 2 more owner reports
“"air bag fault" message is displayed in the info center on the dash and air bag warning light is illuminated. Codes u0170 and b0081 were read at dealership. Parts #92225594 (module) and #92220398 (sensor) are required at an installed cost of approximately $1100. The vehicle has 70,000 miles on it. Entire air bag system is disabled due to this malfunction. Research indicates this is a very common malfunction on these vehicles.”2009 Pontiac G8 · Jul 2016 · 70,000 mi
“The air bag system's passenger presence module failed while the pontiac g8 gt was at the gm dealer being repaired for a different problem. Error codes were b0081 and u0170. The ppm was replaced by dealer's service technician with gm part number 92225595. The repair was not covered by any warranty even though this module is known to be a high-failure item due to a defective design. This is a dangerous defect which may cause the passenger-side airbag to fail to inflate in a crash. The vehicle should be recalled. *tr”2009 Pontiac G8 · Jan 2015 · 84,715 mi
Cars that report U0170 most often
Based on mentions of this code in NHTSA owner complaints.
Frequently asked questions
Can I drive with U0170?
Yes - but a silent impact sensor means the side airbags may not know about a crash on that side. Same rule as the rest of the family: drive if you must, repair without delay.
How much does it cost to fix U0170?
Typical US repair costs range from $60 for the simplest fix (connector cleaning and reseat) to $450 in the worst case. The right number depends on which cause your car has - see the causes list.
Related codes
The codes closest to U0170. They often appear together, and telling them apart is usually what narrows the diagnosis.
Definition per SAE J2012 standard nomenclature. Symptoms, causes and costs are editorial guidance - always confirm with a diagnosis of your specific vehicle.