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.
2004 Ford Mustang Mach 1, AutomaticFACTORY OEM SERVICE PROCEDURE
Remote Keyless Entry Systems DTCS
GENERIC ELECTRONIC MODULE (GEM) DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description | Source | Perform Test |
|---|---|---|---|
| B1217 | Horn Relay Coil Circuit Failure | GEM | GO to PINPOINT TEST E . |
| B1218 | Horn Relay Coil Circuit Short to Vbatt | GEM | GO to PINPOINT TEST E . |
| B1396 | Power Door Lock Circuit Short to Battery | GEM | GO to PINPOINT TEST B . |
| B1397 | Power Door Unlock Circuit Short to Battery | GEM | GO to PINPOINT TEST B . |
| B1498 | Decklid Punch-Out Sensor Ground Short. | GEM | GO to PINPOINT TEST D . |
| B1551 | Decklid Release Circuit Failure | GEM | GO to PINPOINT TEST D . |
| B1553 | Decklid Release Circuit Short to Battery | GEM | GO to PINPOINT TEST D . |
Factory Service Tools
Use the Manual With the Right Hardware
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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.
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