Dongfeng AX7 F21-250 Automated Manual Transmission Service Manual PDF

Description

Dongfeng AX7 F21-250 Automated Manual Transmission Service Manual – PDF DOWNLOAD

Description

The F21-250 Automated Manual Transmission Service Manual is an OEM after-sales technical document published by Dongfeng Motor Corporation Passenger Vehicle Company. Designed for workshop technicians and transmission specialists, this manual offers a complete technical breakdown of the 6-speed F21-250 AMT used in Dongfeng AX7 vehicles.

The manual explains both mechanical and electronic control systems, combining hydraulic theory, clutch/brake operation, solenoid logic, and real-world diagnostic procedures. Detailed diagrams, tables, and flowcharts ensure accurate fault isolation and professional-grade servicing.

📂 Manual Contents (Neatly Categorized)

🔹 1. Transmission Introduction

• Transmission identification & serial number decoding

• Technical specifications & parameters

• Gear ratios (1st–6th + Reverse)

• Torque capacity (≈ 250 N·m)

• ATF specification: AW-1

• Transmission features & design philosophy

🔹 2. Main Structures & Features

• Electronic control system architecture

• TCM (Transmission Control Module) overview

• TCM integrated gear position sensor (Hall type)

• Solenoid valves:

  • S1, S2 (three-way valves)

  • SLC1, SLC2, SLC3, SLB1

  • SLT (linear pressure)

  • SLU (lock-up control)

• Input & output speed sensors

• Fluid temperature sensor characteristics

• Valve body hydraulic logic

🔹 3. Working Principles

• Hydraulic torque converter operation

• Lock-up clutch & semi-engaged clutch control

• Neutral control & hill-hold function

• Self-learning gearshift management

• Manual (+ / –) shift mode operation

🔹 4. Gear-by-Gear Operation (Fully Illustrated)

• 1st to 6th gear power flow diagrams

• Reverse gear operation logic

• Clutch & brake engagement tables:

  • C1, C2, C3 clutches

  • B1, B2 brakes

  • F1 one-way clutch

• Planetary gear set power transmission paths

🔹 5. Fault Diagnosis & Troubleshooting

• Step-by-step diagnostic procedure

• Pre-check & scan tool diagnostics

• Road test procedures

• Functional tests:

  • Time-lag test (N→D / N→R)

  • Stall test

  • Linear pressure test

• Basic symptom matrix

• Detailed DTC tables & diagnostic flowcharts

• Failsafe (limp mode) behavior

🔹 6. Service Data & Specifications

• Tightening torque values

• Solenoid current & resistance values

• Sensor resistance vs temperature charts

• ATF pressure specifications (D / R)

📊 File Details