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.
2012 Ford Fiesta S, Standard TransFACTORY OEM SERVICE PROCEDURE
Electronic Engine Controls
PCM DIAGNOSTIC TROUBLE CODE (DTC) LIST
| DTC | Description | Action to Take |
|---|---|---|
| P0125:00 | Insufficient Coolant Temp For Closed Loop Fuel Control: No Sub Type Information | REFER to ENGINE COOLING . |
| P0128:00 | Coolant Thermostat (Coolant Temp Below Thermostat Regulating Temperature): No Sub Type Information | REFER to ENGINE COOLING . |
| P0504:00 | Brake Switch A/B Correlation: No Sub Type Information | REFER to CRUISE CONTROL . |
| P0531:2F | A/C Refrigerant Pressure Sensor A Circuit Range/Performance: Signal Erratic | REFER to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS . |
| P0532:16 | A/C Refrigerant Pressure Sensor A Circuit Low: Circuit Voltage Below Threshold | REFER to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS . |
| P0533:17 | A/C Refrigerant Pressure Sensor A Circuit High: Circuit Voltage Above Threshold | REFER to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS . |
| P0578:00 | Cruise Control Multi-Function Input A Circuit Stuck: No Sub Type Information | REFER to CRUISE CONTROL . |
| P0579:00 | Cruise Control Multi-Function Input A Circuit Range/Performance: No Sub Type Information | REFER to CRUISE CONTROL . |
| P0617:12 | Starter Relay Circuit High: Circuit Short To Battery | REFER to STARTING SYSTEM . |
| P0645:13 | A/C Clutch Relay Control Circuit: Circuit Open | REFER to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS . |
| P0646:11 | A/C Clutch Relay Control Circuit Low: Circuit Short To Ground | REFER to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS . |
| P0647:12 | A/C Clutch Relay Control Circuit High: Circuit Short To Battery | REFER to CLIMATE CONTROL SYSTEM - GENERAL INFORMATION AND DIAGNOSTICS . |
| P065B:09 | Generator Control Circuit Range/Performance: Component Failure | REFER to CHARGING SYSTEM . |
| P065C:09 | Generator Mechanical Performance: Component Failure | REFER to CHARGING SYSTEM . |
| P0833:00 | Clutch Pedal Switch B Circuit: No Sub Type Information | REFER to CRUISE CONTROL . |
| P0850:00 | Park/Neutral Switch Input Circuit: No Sub Type Information | REFER to STARTING SYSTEM . |
| P0851:00 | Park/Neutral Switch Input Circuit Low: No Sub Type Information | REFER to STARTING SYSTEM . |
| P0A3B:19 | Generator Over Temperature: Component Failure | REFER to CHARGING SYSTEM . |
| P162D:00 | Internal Control Module Cruise Control Performance: No Sub Type Information | REFER to CRUISE CONTROL . |
| P1794:16 | Battery Voltage Circuit: Circuit Voltage Below Threshold | REFER to CHARGING SYSTEM . |
| P1794:17 | Battery Voltage Circuit: Circuit Voltage Above Threshold | REFER to CHARGING SYSTEM . |
| U0120:88 | Lost Communication with Starter/Generator Control Module: Bus Off | REFER to CHARGING SYSTEM . |
| U0167:00 | Lost Communication With Vehicle Immobilizer Control Module: No Sub Type Information | REFER to ANTI-THEFT - PASSIVE ANTI-THEFT SYSTEM (PATS) . |
| U0426:00 | Invalid Data Received From Vehicle Immobilizer Control Module: No Sub Type Information | REFER to ANTI-THEFT - PASSIVE ANTI-THEFT SYSTEM (PATS) . |
| U0469:09 | Invalid Data Received From Starter/Generator Control Module: Component Failure | REFER to CHARGING SYSTEM . |
| U3003:16 | Battery Voltage: Circuit Voltage Below Threshold | REFER to CHARGING SYSTEM . |
| U3003:17 | Battery Voltage: Circuit Voltage Above Threshold | REFER to CHARGING SYSTEM . |
| All Other DTCs | - | REFER to INTRODUCTION - GASOLINE MODELS . |
Factory Service Tools
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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.