Description

ZF AS-Tronic 2 2005 Diagnostics Manual – Factory Fault Code Guide for the ZF AS-Tronic 2

You’ve got a ZF AS-Tronic 2 transmission throwing codes, and you’re standing there with a generic scanner reading “CAN Timeout” or “Clutch self learning error” – and the aftermarket B.S. tells you to replace the whole actuator. That’s a $4,000 mistake, and I’ve seen it happen. This 2005 ZF AS-Tronic 2 Diagnostics Manual is the OEM-compiled document that ZF Friedrichshafen gave its own dealer techs. It lists every diagnostic code and the exact measurement steps you need to take before you touch a wrench. 59 pages, spiral-bound logic, and zero guesswork. If you skip the checklist on page 1, you own the comeback.

Short Circuit/Interruption TA* – Page 5 Diagnostic Codes

Page 5 covers a blanket of 27 diagnostic codes – from code 2 all the way to 81 – all related to short circuits or interruptions in the transmission actuator (TA*). The manual doesn’t just list them; it tells you which pins to back-probe and what resistance values you should see. Need the charge pressure? That’s a different page. But for electrical faults, this is your starting point. If you’re getting a code 28, the manual routes you to page 8 for a specific measurement procedure. That’s how this thing works: it treats each fault like a decision tree, not a parts catalog.

Driveline Retarder Torque (CAN) – Page 7

Torque values are critical in any driveline repair, and the AS-Tronic 2 uses CAN messages to manage retarder torque. Page 7 walks you through the diagnostic code 28 – driveline retarder torque signal failure. If the CAN bus is dropping torque requests, you’ll get driveline shudder or no retarder at all. The manual gives you the CAN message IDs and the acceptable range. Don’t bother with aftermarket wiring diagrams for this; they won’t tell you the bit position of the torque request. This does.

Clutch Self-Learning Error – Pages 14-16

Three pages dedicated to one of the most common headaches: clutch self-learning error (code 117) and its interactions with code 155. Page 14 starts with the measurement procedure for code 117. Page 15 dives deeper into signal conditions. Page 16 covers the combo error 117 with 155 – a situation where the transmission thinks the clutch stroke is wrong and the main transmission isn’t engaging. The manual says: “Prior to replacing the components, it is mandatory to work off the checklist.” I’ve seen shops throw a new clutch actuator at this, only to find a misadjusted shift sensor. The factory checklist catches that.

Can This Manual Handle Air Leakages and Selector Cylinder Issues?

Yes. Page 17 covers air leakages (codes 118, 145, 151, 154). Page 29 hits selector cylinder jammed (codes 151, 153). These are mechanical diagnostics – you need to know if the actuator is losing pneumatic pressure or if the cylinder itself is binding. The manual tells you to measure pilot pressure and check seal integrity. No generic “check for leaks” nonsense. It gives you the pressure thresholds in bar and the expected travel times. For the Wabco transmission actuator (page 28), it covers six different fault codes with a note: “Transmission actuator < 15000” – meaning units built before a certain serial number have specific failure modes. That’s the kind of detail you don’t get from a third-party PDF.

39 Pages of Complaint-Based Diagnostics

From page 44 onward, the manual switches from fault code diagnostics to “Complaints without diagnostics entry” – real-world problems like engine start not possible (page 45-46), transmission does not shift (page 47), clutch judder (page 48), and gear-hunting (page 56-57). For each complaint, the manual lists the probable causes and the order of checks. Example: for “High level of clutch wear / burned clutch” (page 52), it tells you to check the dual-mass flywheel tilt clearance first (page 53). That’s a 20-minute measurement that keeps you from condemning a good clutch. You want to fix buses or trucks? This is the manual that ZF built for its own network.

Source Validity: Why OEM Documentation Matters

This is not a reprint. This is the original 2005 BKS-I/BKS-R release from ZF Friedrichshafen. The OCR excerpt shows the explicit rule: “All disturbing, impacting factors must be checked prior to replacing components.” Aftermarket manuals skip that line because they want you to buy parts. This manual was written for technicians who bill by the hour, not by the part sold. It references specific component campaigns like “General clutch actuator replacement < 42000” and tells you that campaign is closed. That means if you’re working on a transmission below serial 42000, you follow a different procedure. Try finding that in a Chilton product. For more OEM truck transmission diagnostics, check the ZF EST37 2004 Diagnostics Manual – OEM Fault Code Reference or the ZF ERGO-Control EST37 2002 Diagnostics Manual – OEM Fault Codes. For older ZF automatics, the ZF 4HP-22, 4HP-24, 5HP-18, 4HP-18, 5HP-19 Diagnostics Manual – 160 Pages covers a different generation.

Frequently Asked Questions

Does this manual include torque specifications for the transmission?

Page 7 covers driveline retarder torque (CAN) diagnostics. The manual includes torque-related CAN message parameters, but it is not a full rebuild manual with bolt torque values. It focuses on diagnostic code troubleshooting.

What years does this ZF AS-Tronic 2 manual cover?

2005. The document is dated December 07, 2005, and references model variants like Evo-Baureihe CC400 and EvoBus ranges. It applies to AS-Tronic 2 transmissions in service around that period.

Can a home garage mechanic use this without a ZF diagnostic tool?

Yes and no. The manual expects you to have a multimeter and access to CAN bus data. It gives pin voltages and resistance checks. For CAN bus diagnostics, you’ll need a scope or a breakout box. But for mechanical checks like clutch travel or air leakages, you only need basic tools and a pressure gauge.

How many pages are dedicated to actual fault codes versus general theory?

Roughly 40 of the 59 pages are direct fault code or complaint diagnostics. The first 4 pages are administrative. The remaining pages cover specific transmission actuator variants and final complaints. There’s no theory – it’s all action.

If you troubleshoot ZF AS-Tronic 2 transmissions, you need the real factory data. Generic OBD software will not tell you the difference between a short circuit in the TA power supply and a splitter group that won’t disengage. The ZF manual walks you through each fault with OEM-specific measurement steps, torque-related CAN parameters, and serial number–based campaign notes. Stop guessing and start diagnosing. Access the Factory Manual and keep it on your bench. Automotive Industry Overview Automotive Industry Overview