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.
Communications Network: Notes
Communications Network
Symptom Chart(s)
Symptom Chart: Communication Network
Diagnostics in this service information assume a certain skill level and knowledge of Ford-specific diagnostic practices. Refer to: Diagnostic Methods
Symptom Chart
| Condition | Possible Sources | Actions |
|---|---|---|
| The vehicle does not start with the diagnostic scan tool connected to the DLC and/or multiple malfunction indicators are only on when the scan tool is connected to the DLC | Refer to the Pinpoint Test | GO to Pinpoint Test S |
| The PCM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test A |
| The ABS module does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test B |
| The RCM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test C |
| The OCSM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test D |
| The IPC does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test E |
| The BCM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test F |
| The HVAC module does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test G |
| The ACM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test H |
| The APIM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test I |
| The FCDIM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test J |
| The FCIM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test K |
| The GPSM does not respond to the diagnostic scan tool (except vehicles equipped with touchscreen without GPSM) | Refer to the Pinpoint Test | GO to Pinpoint Test L |
| The TCM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test M |
| The RFA module does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test N |
| The PSCM does not respond to the diagnostic scan tool | Refer to the Pinpoint Test | GO to Pinpoint Test O |
| No HS-CAN communication, all modules are not responding | Refer to the Pinpoint Test | GO to Pinpoint Test P |
| No MS-CAN communication, all modules are not responding | Refer to the Pinpoint Test | GO to Pinpoint Test Q |
| No I-CAN communication, all modules are not responding | Refer to the Pinpoint Test | GO to Pinpoint Test R |
| No power to the DLC | Refer to the Pinpoint Test | GO to Pinpoint Test S |
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.
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.