What this code means
On this F-150 PATS system with Phone as a Key, P0601 may indicate that the RFA module is reporting an internal memory or checksum-type problem.
What the vehicle may do
- The vehicle may have Passive Anti-Theft System or Phone as a Key concerns.
- The concern can appear module-related if the code returns after clearing and self-test.
- If the code does not return, the condition may not be active at that time.
Possible fault areas
- Possible RFA module internal memory or electronics fault.
- Possible module-level PATS or Phone as a Key concern.
Diagnostic path
Opening context
On this F-150 with PATS and Phone as a Key, P0601 may point to an RFA module internal memory or checksum-type fault. In plain language, the module may be failing one of its own internal checks, so the customer may have anti-theft or Phone as a Key behavior that feels module-related rather than a normal key or antenna issue. The broad possible fault area here is the RFA module itself, but we still follow the scan-tool path before making that call.
Code detail and suffix caution
For P0601:41, the RFA sets the code when it fails the internal checksum test. One caution: this path identifies P0601:41, but the test question uses a different P0601 suffix. Do not guess from the suffix alone. Treat this as the P0601 RFA internal-memory diagnostic path, and confirm the exact code your scan tool is showing before you make the final decision.
Run the RFA self-test
Start at the RFA module. Using the scan tool, clear all RFA module DTCs. Then run the RFA module self-test. After clearing and retesting, the decision is whether the internal RFA fault is still present.
If the fault returns
If the internal RFA fault is present after the self-test, check OASIS for any applicable Ford direction such as a TSB, GSB, SSM, or FSA. If one applies to this concern, stop this pinpoint path and follow that direction. If nothing applies, the supported call in this path is to install a new RFA module.
If the fault does not return and close
If the code is not present after the clear-and-self-test check, the system is operating correctly at this time. Keep verification separate from the fault call: this path only gives you the RFA self-test result to decide whether the internal fault is still active. Takeaway: do not overcomplicate P0601 here; clear it, self-test the RFA, check for applicable Ford direction if it returns, and only then make the module call. For more diagnostic training, visit stepdiagnostics.com.
Final check
P0601 in this path is mainly about confirming whether the RFA internal fault returns after a clear and self-test, then following the supported branch from that result.
For more guided automotive diagnostics, visit STEP Diagnostics.
