A 2011 Ford Focus Mk III rolled into the bay with codes P087A and P287A, stuck refusing to engage reverse gear and fighting the shift out of first. The technician noted the exact behavior on the job sheet, writing verbatim that the transmission was failing to engage reverse gear and did not shift easily out of first. On the Ford PowerShift DPS6 (6DCT250) dry dual-clutch transmission, these symptoms point straight to a failure on the Clutch B side. Clutch B handles reverse and the even gears. When the control system cannot verify the position of this clutch, it locks those gears out completely to protect the mechanical gear train. You end up with a vehicle that barely leaves the bay. Our diagnostic engine analyzed the codes alongside the symptoms and ranked the physical causes based on actual repair outcomes.
The Transmission Control Module Failure
Our diagnostic engine ranked an internal Transmission Control Module (TCM) circuit or driver stage failure as the primary cause at an 85 percent likelihood with a high severity rating. The TCM on this transaxle (Ford part number AE8Z-7Z369-F) mounts directly to the rear exterior of the casing. It is constantly exposed to severe heat cycles and heavy chassis vibration. Internal solder fractures, thermal fatigue, or output driver failures on the Clutch B sub-circuit will stop the module from processing Hall sensor pulses coming from the actuator.
When this happens, the module logs P087A for a Clutch Position Sensor 2/B Circuit Open fault. Because the module cannot verify that Clutch B has actually disengaged, it triggers P287A (Clutch B Stuck Engaged) as a protective fail-safe strategy. Ford addressed this known internal vulnerability in Customer Satisfaction Program 14M02 and TSB 10237441.
Verifying the module logic
Do not simply order a replacement TCM without confirming the internal failure. The engine suggests a cross-swap diagnostic test of actuator motors A and B. If the fault stays on the B circuit after the swap, you know the motor itself is fine. Next, perform a TCM power and ground voltage drop test under load. Finally, log the bi-directional actuator command and Hall sensor feedback to confirm the module is failing to process the return signal.
Actuator Motor and Mechanical Binding
If the TCM tests clear, the issue usually sits further down the bellhousing. The engine ranked an internal electrical or sensor failure of Clutch Actuator Motor B at a 75 percent probability. This lower actuator drives the Clutch 2 engagement mechanism. It contains a 3-phase brushless DC motor and three internal Hall-effect position sensors. Sitting at the bottom of the bellhousing, Actuator B is highly exposed to road spray, puddle submersion, and water ingress through bellhousing inspection apertures. Moisture gets past the motor housing, corrodes the internal sensor board, and seizes the internal pinion bearings. This produces code P087A due to lost sensor feedback and P287A because the motor cannot release the clutch lever.
A mechanical bind in Clutch Fork B or the release bearing is another highly likely culprit, ranking at a 70 percent probability. The actuator motor turns an internal ball screw spindle that levers the fork against heavy spring tension. Over time, friction material dust from the dry plates mixes with ambient moisture or minor oil mist from input shaft seals. This forms an abrasive sludge that gums up the ball bearings and guide tracks. When the actuator retracts, a seized fork fails to snap back. The TCM detects the discrepancy between commanded travel and physical release, setting both codes.
Pinpointing the lower components
To test the actuator, inspect the electrical connector for water ingress and pin corrosion. Measure the phase-to-phase winding resistance on the motor and check for smooth manual gear drive rotation. For the mechanical fork, perform a manual rotation and snap-back test on the ball screw. Inspect the bellhousing cavity for heavy clutch dust or fluid leakage, and complete a full stroke revolution count check on the fork itself.
Wiring Harness Vulnerabilities
We also cannot ignore the wiring harness, which ranked as a 50 percent probability for this specific fault combination. The harness running between TCM connector C1750B and Actuator B carries the three motor phase drive circuits along with the 5V power, ground, and signal lines. Given its low position near the radiator support and subframe, chassis vibration and engine roll take a toll over time.
Chafing against the transmission casting edges, fractured internal copper strands inside the conduit, or spread female pin terminals will interrupt the sensor signal and generate an open circuit code. Run an end-to-end wire continuity and load test from the TCM to the plug. Perform a terminal pin drag and retention tension test on the Actuator B female connector to ensure tight physical contact.
Following the evidence in the bay
Treating P087A and P287A as isolated parts failures usually leads to a scattered diagnostic process. You have to evaluate the module, the actuator, the mechanical fork, and the harness as one interconnected system to find the real fault. Do you see a high volume of these DPS6 mechanical binds in your own shop, or have most of them already had their modules replaced? Let us know.
