What Does C1946 Mean?
The restraint control module has detected an open circuit in the seat track position switch, which is used to determine the driver or passenger seat's fore/aft position for airbag deployment force calibration. Modern vehicles adjust airbag deployment intensity based on seat position to reduce injury risk. The airbag system may default to maximum deployment force, and the airbag warning light will likely be illuminated.
Common Causes
35%
Seat track position switch connector disconnected — often from items pushed under the seat snagging the wiring
25%
Broken or chafed wire in the seat wiring harness due to repeated seat movement
20%
Faulty seat track position switch (internal open circuit)
15%
Poor connection at the body-to-seat harness junction connector under the seat
5%
Corroded pins at the restraint control module connector
Diagnostic Steps
1
Check under the affected seat (usually driver's side) for any disconnected connectors. Items stored under the seat frequently catch and disconnect the seat track switch harness. Reconnect and clear codes if found.
2
With the connector accessible, check for battery voltage on the supply wire and a good ground. Measure the signal wire resistance — it should change as the seat is moved forward and back (typically a variable resistor or discrete switch positions).
3
Inspect the wiring harness that flexes as the seat slides forward and back. Look for broken or chafed wires, especially at the flex point where the harness transitions from the seat frame to the floor. This is the most common failure point.
4
If the wiring and connector are good, measure the seat track switch directly. Disconnect it and check resistance across the switch terminals while moving the seat. An open circuit (infinite resistance) in any position confirms a failed switch.
5
Check the connector at the restraint control module for backed-out or corroded pins on the seat track switch circuit.
Estimated Repair Cost
$25 - $300
Parts + labor, varies by vehicle and location
The restraint control module has detected an open circuit in the seat track position switch, which is used to determine the driver or passenger seat's fore/aft position for airbag deployment force calibration. Modern vehicles adjust airbag deployment intensity based on seat position to reduce injury...
The most common cause of C1946 (Seat Track Position Switch Circuit Open) is: Seat track position switch connector disconnected — often from items pushed under the seat snagging the wiring
Typical repair costs for C1946 range from $25 to $300, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Airbags may still deploy in a crash, but without seat position data, the deployment force may not be optimized for occupant position, potentially increasing injury risk. The airbag warning light will be on. This should be repaired soon, as the restraint system is not operating at full capability.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to C1946 to identify the root cause.
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Quick Info
Category
Chassis
System
Supplemental Restraint System (SRS)
Difficulty
Type
Manufacturer
Recommended Tools
OBD2 Scanner
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