Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Fire Suppression Module (FSM) Diagnostic Trouble Code (DTC) Index
2010 Mercury Mariner Hybrid, AWDSECTION Fire Suppression Module (FSM) Diagnostic Trouble Code (DTC) Index
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
FIRE SUPPRESSION MODULE (FSM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX
| DTC | Description | Source | Action |
|---|---|---|---|
| B1921 | Air Bag Diagnostic Monitor Ground Circuit Open | FSM | GO to PINPOINT TEST K . |
| B29B3 | Fire Suppression Indicator Lamp Circuit Failure | FSM | If the indicator is never on, GO to PINPOINT TEST K . If the indicator is always on, GO to PINPOINT TEST L . |
| B29B4 | Fire Suppression Indicator Lamp Circuit Short to Battery | FSM | GO to PINPOINT TEST L . |
| All other DTCs | - | FSM | REFER to FIRE SUPPRESSION SYSTEM . |
RENDER: 1.0x
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.