What Does B1997 Mean?
This code indicates the Airbag Control Module (ACM) has detected a short to ground in the passenger side-mounted (thorax/torso) airbag electrical circuit. The ACM continuously monitors airbag circuit resistance and when it detects abnormally low resistance (typically below 0.5-2 ohms), it interprets this as a short circuit to vehicle ground. This fault will disable the passenger side airbag and illuminate the airbag warning light on the instrument cluster.
Safety Warning
The vehicle should not be driven as the passenger side airbag is disabled and will not deploy in a collision, creating severe injury risk for passengers. The airbag warning light will remain illuminated indicating a critical safety system fault requiring immediate professional repair.
Common Causes
45%
Damaged or chafed wiring harness under the passenger seat where conductors have worn through insulation and are grounding against the seat frame or floor pan
30%
Faulty side airbag module internal short circuit or damaged connector terminals on the airbag inflator itself
15%
Corroded or damaged connector pins at the seat base connector or inline harness connectors allowing moisture intrusion and short circuits
10%
Failed Airbag Control Module internal driver circuit causing false short-to-ground detection
Diagnostic Steps
1
Step 1: Perform a visual inspection of the passenger seat wiring harness, particularly where it routes under the seat rails and along movement points. Look for pinched, chafed, or damaged wires with exposed copper. Check the airbag connector at the seat base for corrosion, pushed-out pins, or damage.
2
Step 2: Disconnect the passenger side airbag connector at the seat (follow manufacturer's safety procedures and wait appropriate time after battery disconnect). Using a digital multimeter set to resistance mode, measure resistance from each airbag circuit wire to vehicle ground. Reading should be infinite (OL); any measurable resistance below 10k ohms indicates a short to ground in the harness.
3
Step 3: With airbag still disconnected, measure resistance across the airbag inflator terminals. Typical specification is 2-4 ohms (consult service data). If reading is below 0.5 ohms or shows direct continuity to ground when one lead is on inflator terminal and other on airbag housing, the airbag module itself is shorted internally.
4
Step 4: If harness and airbag module test normal, inspect all connectors between the seat and ACM for corrosion, water intrusion, or damaged pins. Test harness continuity and isolation by measuring resistance between airbag circuit wires and ground at the ACM connector (harness side) with seat-side disconnected.
5
Step 5: After repairs, reconnect all components, clear codes, and perform airbag system self-test. Verify airbag warning light extinguishes and no codes return. Cycle seat movement through full range and recheck for code return to ensure repair is complete.
Estimated Repair Cost
$150 - $1,200
Parts + labor, varies by vehicle and location
This code indicates the Airbag Control Module (ACM) has detected a short to ground in the passenger side-mounted (thorax/torso) airbag electrical circuit. The ACM continuously monitors airbag circuit resistance and when it detects abnormally low resistance (typically below 0.5-2 ohms), it interprets...
The most common cause of B1997 (Passenger Sid, Side mount Airbag Circuit Short to Ground) is: Damaged or chafed wiring harness under the passenger seat where conductors have worn through insulation and are grounding against the seat frame or floor pan
Typical repair costs for B1997 range from $150 to $1,200, depending on the vehicle, location, and whether you do it yourself or go to a shop.
The vehicle should not be driven as the passenger side airbag is disabled and will not deploy in a collision, creating severe injury risk for passengers. The airbag warning light will remain illuminated indicating a critical safety system fault requiring immediate professional repair.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to B1997 to identify the root cause.
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Quick Info
Category
Body
System
Supplemental Restraint System (SRS/Airbag)
Difficulty
Type
Manufacturer
Recommended Tools
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