Troubleshooting Automatic Transmission Problems in a 2021 Ford Explorer

Tools Required

• OBD-II Scanner
• Torque Wrench
• Transmission Fluid Dipstick
• Funnel
• Clean Rags
• Socket Set
• Screwdrivers (flathead and Phillips)
• Creeper (optional for under-vehicle access)
• Safety Gloves and Glasses

Step 1: Initial Inspection

1. Visual Inspection:

   • Check for any visible transmission fluid leaks under the vehicle.
   • Inspect the transmission fluid level and condition using the dipstick.
   • Look for any signs of damage or wear on the transmission casing and hoses.

2. Fluid Condition:

   • Pull the transmission dipstick, wipe it clean, and reinsert it. Remove it again to check the fluid level.
   • Evaluate the color and smell of the fluid. It should be bright red and have a slightly sweet smell. Dark brown or burnt smelling fluid indicates degradation.

Step 2: Scan for Trouble Codes

1. Connect OBD-II Scanner:

   • Locate the OBD-II port (usually under the dashboard near the driver's seat).
   • Connect the OBD-II scanner and turn on the ignition (without starting the engine).

2. Read Codes:

   • Follow the scanner instructions to retrieve any Diagnostic Trouble Codes (DTCs).
   • Note down any codes related to the transmission (e.g., P0700, P0710, etc.).

Step 3: Analyze Codes

1. Refer to Service Manual:

   • Use the vehicle’s service manual to interpret and analyze the trouble codes.
   • Identify if the codes relate to specific sensors, solenoids, or other transmission components.

2. Research Known Issues:

   • Look for TSBs (Technical Service Bulletins) or known issues related to your specific model and year.

Step 4: Check Transmission Fluid Level

1. Fluid Level Check:
   • With the engine running and the transmission in park, use the dipstick to ensure the fluid is at the correct level.
   • If low, top up with the manufacturer-recommended transmission fluid.

Step 5: Examine Electrical Connections

1. Inspect Wiring and Connectors:
   • Check the wiring harness connected to the transmission for any signs of fraying or damage.
   • Ensure all connectors are seated properly and free of corrosion.

Step 6: Test Drive

1. Conduct a Test Drive:
   • Take the vehicle for a short drive to replicate the symptoms.
   • Pay attention to shifting behavior, unusual noises, and any dashboard warnings.

Repair Instructions

If Fluid is Low

1. Add Transmission Fluid:
   • Using a funnel, add the recommended transmission fluid through the dipstick tube until the correct level is reached.
   • Recheck fluid level after adding.

If Codes Indicate Sensor Malfunction

1. Replace Faulty Sensors:
   • If a specific sensor code is present (e.g., speed sensor), locate the sensor per the service manual.
   • Disconnect the wiring harness, remove the sensor using the socket set, and install the new sensor.
   • Reconnect the wiring harness and clear the DTCs with the OBD-II scanner.

If Fluid is Contaminated

1. Transmission Fluid Change:
   • Drain the old transmission fluid by removing the drain plug (if available) or by dropping the transmission pan.
   • Replace the filter and clean the pan before reinstallation.
   • Refill the transmission with fresh, manufacturer-recommended fluid.

If Mechanical Issues are Present

1. Professional Assessment:
   • If mechanical issues (like internal damage) are suspected, consult a professional transmission technician for further diagnostics and potential overhauls.

Conclusion

After completing these steps, recheck the vehicle’s operation. If problems persist, further in-depth diagnostics may be required, including pressure tests or internal inspections. Always refer to the specific repair manual for the 2021 Ford Explorer for detailed procedures and specifications.