Ford Fiesta 1.4-2003, Not cranking Transceiver Fault

[Msmax]

Hello guys,

Just like to share my experience working on a Ford Fiesta 1.4 from MY2003 with a SIM-22 PCM.

Symptoms:
- Car did not crank,
- Key symbol in dash always blinking.

FoCom Diagnose results from PCM:
- P2107 Throttle actuator control module processor
- P0562 System Voltage: LOW
- B1681 Transceiver
- P1000 OBD system set-up tests not complete

At first I checked al direct power connections to PCM which seemed to be fine.
Next I checked the transceiver module near the ignition key with a inductive tester with LED, see picture with green PCB.
As soon the key was turned I could see the LED blinking on the inductive tester, from which I could say that:
- the transceiver coil is OK
- and looking at the blinking rate of the LED I could see that there was communication between key and transceiver.

Just after hours of playing I was to give up and would start looking for a new PCM with matching keys, I saw one more power connection to the PCM fed via relay R11. This relay is mounted on the fuse board plate near passenger feet. Changing this one with relay R7 (for the starter) solved all the problems. I could reset all errors in the PCM and the key symbol also did not blink anymore... and the car started right away.

May be this information will be helpful to some one in the future.

Attached some pictures showing:
- the relays on the fuse board
- the legend of the fuse board
- inductive tester

[amlop]

I want to thank you for this post because it has helped me rule out and I have had the same problem with the fault code: B1681

By loosening that screw, remove the connector and plug it back in. Solve the problem. I want to provide this photo in case someone happens to it.


WhatsApp Image 2023-08-31 at 23.38.50.jpg