Navigating the complexities of your Ford vehicle’s onboard diagnostics can be daunting, especially when faced with OBDII codes. Among these, the Ford Obdii Code 1445 signals potential issues within your car’s Evaporative Emission Control System (EVAP). While the original text provided does not explicitly mention “1445”, it details diagnostic procedures highly relevant to EVAP system faults, often associated with codes like P1445 and P0443. This guide will help you understand and troubleshoot these related EVAP system problems in your Ford.
Understanding the EVAP system is crucial. It’s designed to prevent harmful fuel vapors from escaping into the atmosphere. When the system detects a fault, it triggers a Diagnostic Trouble Code (DTC), like those discussed in the original text, to alert you to a problem. Let’s delve into the diagnostic steps to address these issues, keeping the principles of the provided guide in mind.
Diagnosing EVAP System Faults: A Step-by-Step Guide
Based on the original diagnostic procedures (HW39, HW40, HW41, HW42, HW43), here’s a structured approach to pinpointing EVAP system problems, which can trigger codes related to P1445.
Step 1: Checking the Purge Flow (PF) Sensor Circuit
The Purge Flow sensor is critical for monitoring the flow of fuel vapors. A fault in its circuit can lead to incorrect readings and trigger DTCs. Here’s how to check it, adapted from HW39:
- Key On, Engine Off: Turn your Ford’s ignition to the “Key On, Engine Off” position.
- Access EVAPPF PID: Using an OBDII scan tool, access the EVAPPF PID (Evaporative Purge Flow) reading. This allows you to monitor the sensor’s voltage.
- Sensor Manipulation:
- Tap the PF sensor lightly.
- Wiggle the PF sensor connector and harness between the sensor and the Powertrain Control Module (PCM).
- Observe EVAPPF PID: Watch for sudden changes in the EVAPPF PID voltage. A significant jump (greater than 4.80 volts) indicates a potential fault.
Fault Indication:
- Yes (Fault Indicated): The problem lies within the PF sensor circuit. Isolate and repair the fault, then perform a PCM reset to clear DTCs and re-run a Quick Test.
- No (No Fault Indicated): If no fault is detected, proceed to Pinpoint Test Step Z1, consulting your vehicle’s service manual for “PF PID and Possible causes.”
This step helps identify intermittent opens or VPWR shorts in the PF sensor circuit.
Step 2: Inspecting the EVAP Canister Purge Valve Circuit
DTC P0443, mentioned in HW40, points to potential issues in the EVAP canister purge valve circuit. This valve controls the flow of fuel vapors from the canister to the engine.
Possible Causes (from HW40):
- Damaged EVAP canister purge valve
- Open circuit in the EVAP CANISTER PURGE or VPWR circuit.
Diagnostic Steps (adapted from HW41):
- Install Breakout Box: Install a breakout box to access the PCM circuits, leaving the PCM disconnected for safety.
- Resistance Measurement: Measure resistance between specified PCM test pins (e.g., pin 67 or 56 and pin 71). Refer to your vehicle’s wiring diagram for precise pin locations.
- Valve and Harness Manipulation:
- Lightly tap the EVAP canister purge valve.
- Wiggle the valve connector and harness between the valve and the PCM.
- Observe Resistance Change: Monitor for resistance changes during manipulation.
Resistance Reading Analysis:
- Resistance Change Detected: If the resistance reading changes to below 30 ohms or above 90 ohms (or above 38 ohms for vehicles using test pin 56), it indicates an intermittent fault. Isolate and repair the circuit, reset the PCM, and retest.
- No Resistance Change: If no change is observed, proceed to Pinpoint Test Step Z1, referencing resistance readings and possible causes from your service manual.
Step 3: EVAP System Leak Testing
Leaks in the EVAP system are common culprits for DTCs. HW42 and HW43 detail a pressure test using a Rotunda Evaporative Emission System Leak Tester (or equivalent).
Leak Test Procedure (Summarized from HW42 & HW43):
- Prepare the System: Plug the atmospheric vent cap on the EVAP canister (if applicable) and remove the fuel filler cap.
- Install Leak Tester: Connect the leak tester to the fuel filler pipe, including a nitrogen or argon gas supply and pressure regulator.
- Isolate Purge Valve Hose: Disconnect and plug the fuel vapor hose to the PF sensor (or EVAP canister purge valve) from the intake manifold vacuum source.
- Pressurize System: Pressurize the EVAP system to 6.74 kPa (27 in-H2O) with the tester.
- Observe for Leaks: Monitor the tester for pressure drops over two minutes (self-test) and then during the EVAP system leak test. Listen for vacuum leak noises and check for fuel vapor odors.
Leak Test Results:
- Pressure Holds: If the pressure holds, the leak is likely not in the main EVAP lines. Proceed to HW43 to further isolate potential leak locations, such as the EVAP canister itself.
- Pressure Does Not Hold: A leak is present. Systematically isolate sections of the EVAP system (as described in HW43) to pinpoint the leak’s location. Check hoses, connections, and components for damage. Repair or replace as needed.
Post-Repair Verification (from HW42 & HW43):
After any repairs:
- Reconnect Components: Reconnect all hoses and components. Reinstall the fuel filler cap (tighten until it clicks once).
- PCM Reset: Perform a PCM reset to clear DTCs.
- Drive Cycle: Drive the vehicle as instructed (including steady speed over 80 km/h) while monitoring the EVAPPDC PID on a scan tool to ensure the EVAP system cycles correctly.
- Re-run Quick Test: Perform another Quick Test to verify the DTC is resolved and the symptom is gone.
Conclusion
Troubleshooting Ford OBDII code 1445, and related EVAP system codes, requires a systematic approach. By following these diagnostic steps, adapted from the provided service procedures, you can effectively identify and address issues within your Ford’s EVAP system. Remember to consult your vehicle’s service manual for specific test pin locations, torque specifications, and detailed procedures. If you are unsure about any step, it’s always recommended to consult a qualified automotive technician. Addressing EVAP system faults not only resolves annoying check engine lights but also ensures your vehicle runs efficiently and minimizes harmful emissions.
