Airbag Deployment Indication Input Fault
The airbag system's deployment sensor isn't communicating properly with the safety control module, like a smoke detector with a broken wire that can't signal when triggered. This fault prevents the system from confirming it received the deployment signal during a crash.
The SRS control module monitors the airbag deployment indicator circuit for a valid voltage signal when deployment is triggered. It checks for proper circuit continuity and voltage levels during both normal operation and simulated deployment tests. A missing, intermittent, or shorted signal causes the fault to set.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Deployment Signal Voltage | 5V nominal with clean transitions | Below 0.5V or above 5.5V, or open circuit |
| Circuit Resistance | Less than 10 ohms end-to-end | Greater than 50 ohms or infinite resistance |
Code C1943 is classified as a serious fault. If your check engine light is flashing — not just steady — pull over safely and do not continue driving. A flashing CEL indicates an active misfire or critical failure that can cause catalytic converter damage within minutes or permanent engine harm within miles. Contact a certified mechanic immediately. Do not attempt roadside repairs on high-severity codes unless you are trained to do so.
Once the fault is repaired, C1943 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.