This procedure addresses a common misconception: the 2015-2020 Ford F-150 3.5L EcoBoost with automatic transmission does not use a kickdown cable, as it features an electronically controlled transmission.

Warnings

Tools required

Parts

• Throttle position sensor (if faulty) × 1 — Use OEM specification
• Transmission range sensor (if faulty) × 1 — Use OEM specification

Preparation

1. Verify the complaint: delayed downshifts, poor passing response, or lack of wide-open-throttle downshifts
2. Ensure vehicle is on level ground with parking brake applied
3. Allow engine to cool if recently operated
4. Connect OBD-II scanner to retrieve any stored diagnostic trouble codes

Procedure

1. 1

   Retrieve diagnostic trouble codes
   Using an OBD-II scanner, retrieve all stored and pending diagnostic trouble codes from the powertrain control module (PCM) and transmission control module (TCM). Document all codes related to throttle position sensor, accelerator pedal position sensor, transmission range sensor, or shift solenoids. Common codes include P0120-P0124 (TPS), P2135 (TPS correlation), P0708-P0709 (transmission range sensor).
2. 2

   Test throttle position sensor signal
   Access live data through the OBD-II scanner. Monitor throttle position sensor (TPS) voltage while slowly depressing the accelerator pedal from idle to wide-open-throttle. TPS signal should smoothly increase from approximately 0.5V at idle to 4.5V at WOT without jumps or dropouts. The PCM uses this signal to command transmission downshifts.
3. 3

   Verify accelerator pedal position sensor
   Monitor accelerator pedal position sensor (APP) data through scanner live data. The system uses dual APP sensors for redundancy. APP1 and APP2 should both show smooth progression from 0-100% as pedal is depressed, with APP2 reading approximately half the voltage of APP1. Any disagreement between sensors will limit transmission downshift capability.
4. 4

   Check transmission range sensor
   With engine running and brake applied, shift through all gear positions while monitoring transmission range sensor (TR sensor) data. Scanner should display correct gear selection (P, R, N, D, M) for each shift lever position. Incorrect TR sensor data will prevent normal shift patterns and downshift operation.
5. 5

   Inspect electronic throttle body
   Remove engine cover if equipped. Locate the electronic throttle body on the intake manifold. Visually inspect throttle body for carbon buildup on throttle plate and bore. Excessive carbon can restrict throttle movement and affect TPS signal accuracy. If carbon is present, throttle body cleaning may be necessary before replacing sensors.
6. 6

   Test transmission shift solenoid function
   Using scanner with bidirectional control capability, command individual shift solenoids on and off while monitoring transmission behavior. All solenoids should activate without hesitation. Solenoid pack is internal to transmission and requires transmission disassembly if faulty. Check transmission fluid level and condition before condemning solenoids.
7. 7

   Verify transmission fluid level and condition
   With engine at operating temperature and running, shift through all gears and return to Park. Remove transmission dipstick (if equipped - 2017+ models may not have dipstick) and check fluid level in PARK with engine running. Fluid should be between MIN and MAX marks and appear red/pink without burning smell. Low fluid or degraded fluid can cause shift quality issues mimicking mechanical problems.
8. 8

   Perform PCM adaptive learning reset if needed
   If all sensors test within specification but shift quality remains poor, perform a transmission adaptive learning reset using the OBD-II scanner. This clears learned shift patterns and allows the TCM to relearn optimal shift points. After reset, test drive vehicle through multiple acceleration and deceleration cycles to allow relearning.
9. 9

   Replace faulty sensors if identified
   If diagnostic testing identified a faulty throttle position sensor or transmission range sensor, replace the defective component. For TPS (integrated into throttle body), remove electrical connector and mounting bolts, install new throttle body assembly. For transmission range sensor, remove electrical connector, remove sensor mounting bolts, install new sensor. After replacement, clear codes and perform relearn procedure.
   Torque spec

   Sensor Bolts12 Nm (9 lb-ft)

Reassembly

1. Reinstall engine cover if removed, ensuring all clips are properly seated
2. Reconnect any electrical connectors that were disconnected during diagnosis
3. Clear all diagnostic trouble codes from PCM and TCM memory
4. If throttle body was cleaned or replaced, perform throttle relearn procedure per Ford service manual

Verification

• Start engine and verify no check engine light or transmission warning lights are illuminated
• Perform test drive including moderate and wide-open-throttle acceleration from various speeds to verify proper downshift response
• Verify transmission downshifts promptly when accelerator pedal exceeds 75% travel at cruising speeds
• Confirm passing gear downshift (4th to 3rd or 6th to 4th depending on transmission) occurs smoothly under heavy throttle
• Re-scan vehicle for diagnostic codes and verify no new codes have set

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