P1260 on 1997-2004 Ford F-150 (XL, XLT, Lariat, FX4, King Ranch) — Theft Detected - Vehicle Immobilized
1 vehicles · 1 makes · $100-$500 repair
Most Reported On
P1260 is an OBD-II diagnostic trouble code meaning “Theft Detected - Vehicle Immobilized.” Manufacturer-specific code, defined on Ford, Lincoln, Mercury and Mazda (and Ford-derived Jaguar/Land Rover applications) as a PATS/immobilizer security-protocol violation: the PCM either received a theft signal from the anti-theft module or never received a valid authorization signal, and has disabled the engine. The usual symptom is an engine that cranks but will not start, or starts and immediately dies, often with a flashing security light. Note that some other manufacturers assign this same number to unrelated systems, so confirm the definition for your make before diagnosing. This code is most commonly reported on 1997-2004 Ford F-150 (XL, XLT, Lariat, FX4, King Ranch), with repair costs ranging from $100 to $500.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
P1260 does not use the standard P/B/C/U prefix. It may be a manufacturer-specific code, so verify that a scanner supports your exact year, model and module before buying.
FAQ
What does P1260 mean?
P1260 stands for "Theft Detected - Vehicle Immobilized." Manufacturer-specific code, defined on Ford, Lincoln, Mercury and Mazda (and Ford-derived Jaguar/Land Rover applications) as a PATS/immobilizer security-protocol violation: the PCM either received a theft signal from the anti-theft module or never received a valid authorization signal, and has disabled the engine. The usual symptom is an engine that cranks but will not start, or starts and immediately dies, often with a flashing security light. Note that some other manufacturers assign this same number to unrelated systems, so confirm the definition for your make before diagnosing.
What are the most common causes of P1260?
The most common causes of P1260 are: Unprogrammed, damaged, or worn transponder key, Faulty or misaligned transceiver ring around the ignition lock cylinder, Weak battery, improper jump-start, or a battery replacement causing a failed immobilizer handshake, Wiring or connector fault between the immobilizer/anti-theft module and the PCM, Incorrectly programmed PCM or instrument cluster (for example after a used-module swap), A genuine prior theft attempt that latched the immobilized state. The specific cause varies by vehicle.
How much does it cost to fix P1260?
Repair costs for P1260 range from $100 to $500, depending on the vehicle and root cause.
Which vehicles are affected by P1260?
Au7o has documented P1260 across 1 vehicle models from 1 manufacturers: Ford.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.