2013 Focus Cluster, BCM, and PATs system

[twenglish1]

Been trying to troubleshoot my 2013 Focus Titanium (pushbutton start), while attempting to program a new fob to the car, started with being unable to add a new fob, but it turns out the issue is not the fob, it is with the PATS system/transceiver ring inside the steering column that is not reading the new fob, attempting to start the car with the working fob (battery removed) and held against the column transceiver ring to simulate a fob with a dead battery, this results in the no key detected message. This is the same function as the slot in the center console that newer models use for emergency starting if fob is no longer transmitting due to dead battery or other issue. This is also the same transceiver ring that is used to read conventional keys on vehicles without pushbutton start. I have confirmed 12v and GND at the transceiver module, and scoping the serial data lines between the BCM and transceiver ring results in no serial activity at all while attempting to start the vehicle. Tried a different transceiver ring as well with no luck. If i am understanding correctly, the key data is transmitted/validated between the BCM and cluster. I have also checked all connectors at the BCM, no corrosion or damage, and confirmed continuity of power, ground, TX and RX lines between BCM and transceiver ring. All checks out, not sure where to go next. Hoping someone here will be able to help.

[VTXU8]

If the vehicle starts with the battery in the working key fob, then I would rule out the T- ring as the issue. Possible it may be a PATS issue in the Instrument Cluster. Do you have Forscan full licence software and a Automatic HS/MS OBD like vlinker FS? Use it to program new fob or see if there are any DTC's related.

[twenglish1]

I do have full licensed forscan with a compatible cable, OBD Link EX i believe. When attempting to add the new key, after the 10 minute wait while holding the fob against the column, also tried taking the round cover off and inserting the fob into the transceiver ring, i get no key detected, even attempted to add the working key again because i know it works, it should have returned a key programmed message or similar, but i get no key detected. It is my understanding that the pushbutton start vehicles use a separate system and module located above the headliner to pick up the fob unless the fob is not transmitting which then it can be held against the column and read like a conventional key. Only fault on the BCM indicates the failed programming attempt. No other modules had any faults.

[VTXU8]

Interesting that there is no fault codes. Do these models have a START/STOP module located on the steering column like some Mazda's of the equivalent year do? I know Ford and Mazda shared a lot of technology up to a certain year. The Start/Stop modules were commonly known to fail causing the same problem you've described with no fault codes and steering locked.

[twenglish1]

Yeah definitely strange, i originally thought the new fob i purchased was incompatible, but then came across this issue. The car does not have start/stop enabled/setup, i am unsure if it has the module for it. I have checked the BCM/fuse block under the dash on passenger side, the transceiver ring wires directly to it, confirmed continuity of all 4 wires between the transceiver ring and the BCM, 12v, GND, and the two serial data lines, no shorts to ground on any of them either, the BCM/fuse block has 5amp fuse for power to the transceiver. It is good and not corroded. I haven't been able to find any corrosion or other issues with the connectors at the BCM or transceiver. If there was a communication problem between the Cluster and the BCM or a power/ground issue with either, there would be a ton of issues, as far as i know there isn't any other system that is having any issues

[VTXU8]

Start/Stop module is part of the ignition/security system on cars with push button start. Located on the steering column, it engages/disengages the steering lock shaft via a motor. It is part of the PATS. And if it's faulty, you will get no lights or reds on the dash and steering will remain locked. Not sure about your vehicle but Mazda's,Mitsubishi,Nissan,Hyundai's etc do. You can hear the motor operate for roughly 1 sec or 2 when you push the Start button, releasing the steering lock.