P0735: Fifth-gear ratio evidence must be separated from engagement evidence

P0735 identifies the fifth-gear result in Ford's general ratio monitor. It reports a disagreement with the expected commanded relationship, not a direct measurement proving that one particular clutch is worn. The controller needs credible speed and gear-state inputs to make that comparison.

Use an eligible held-gear interval

The forward-ratio example requires adequate torque, throttle and shaft speeds, plus a period without shifting. Ford describes a mismatch above 30 rpm lasting more than 2.5 seconds and recurring six times across key cycles without detected solenoid faults. A trace of the shift transition alone does not reproduce that held-gear evaluation.

The repeated-event requirement also matters after a repair or an intermittent event. One normal fifth-gear observation provides less information than a record showing the relevant check completed under its documented operating conditions.

The DCT has a separate state vocabulary

In the TR9070 table, P0735 means unknown fifth-gear state. Failure to engage fifth is separately listed as P074D, and failure to disengage it as P073A. Those codes should not be treated as interchangeable descriptions of P0735.

Preserve the reporting transmission, commanded gear, shift phase, shaft speeds and companion electrical codes. If those inputs disagree, establish which observation is reliable before assigning a mechanical cause. The source supplies no universal fifth-gear component location or replacement decision; the exact gearbox procedure must resolve that next step.

Source and applicability

Ford 2024–2025 gasoline OBD operation summary, July 16 2024 revision; only the cited monitor and transmission architectures. No individual vehicle fitment or universal calibration is inferred. Ford PDF, page 152. Ford PDF, page 153. Ford PDF, page 167.