Introduction
Keep your car in a healthy condition, use a diagnostics tool to check if something is wrong. 928 S4/GT is one of the first cars with a diagnostics system. On the market expensive tools (like Bosch Hammer KTS300/KTS301) are available. But one of the goals of this tool is to be a cheap (cost effective) tool special for 928/944/964/968/993 enthousiasts !

The story: Few weeks ago I had problems with my car. It does not have the power which I expected from the car. Hmmmm what could be the problem. I connected my diagnostics tool (DT928) on the 928 diagnostics bus, checked the error codes of the ECU and EZK and yes, errormessage "knock sensors faulty" appeared. I asked a good friend of mine what to do. He told me to clean the connections between the cable harnass and the cable at the knock sensors. I also cleaned the cable connector at the EZK. The next day I drove to my work... Hmmm power is back !!! In the evening I connected the DT928 tool on the bus and the error codes were gone :-))

The 928-ECU-repair diagnostics tool (DT911/DT928/DT944/DT999) is ready !

DT928
The DT9xx tool is a PC controlled diagnostics tool. The software runs on a Win98/Win2000, XP and Vista based PC. Between the car and the PC, a small box is necessary that converts the signals of the PC to the signals of the car. The small box will be connected between the COM of your PC and the car (diagnostics bus) with a 19-way cable (* see note on tool-page). Below you will see a picture of the small Printed Circuit Board (PCB) which is the signal converter between the PC and the car. External power consumption for the small box is NOT necessary (power is available on the diagnostics bus of the car).



PCB of the DT9xx

Supported modules in the 928 (DT928)
The S4/GT/GTS has several modules which are all connected to the K/L line of the diagnostics bus. The modules are: ECU, EZK, PSD, RDK, Airbags and Alarm system. Currently the DT928 tool is able to diagnose all the 6 modules. An additional feature of the DT928 is that the tool is able to activate the dashboard diagnostics program (read: engine-, coolant-temperature, coolant-, oil-pressure, and more). But this feature is only possible on 928's with a digital dashboard !
LH:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Perform drive links tests: fuel tank vent, resonance flap, fuel injectors and idle stabilizer.
  • Read input signals: throttle WOT/idle, Airco and idle speed/drop.
  • Read actual values: battery voltage, reference voltage, ezk_on signal and engine temperature sensor.
  • Read actual values active: MAF sensor value, OXY sensor value (Lambda), speed sensor, coding 4 / 8(only for cars without cat).
  • Perform the system adaptation program.


    • EZK:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Read actual values: engine temperature, speed, load signal.
  • Read sensor information: coding, transmission switch, throttle signal.
  • Perform runtime knock registration.


    • PSD:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Perform drive tests: bleed procedure, check transverse lock.


    • RDK:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Read sensor information: HF sending unit, ABS speed sensors.
  • Read input signals: pressure switches.


    • Airbags:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Read downtime.
  • Read date of crash.


    • Alarm:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Perform drive links: activate horn, turn signals, interrior lights, locks, etc.
  • Read input signals: switches in engine-, luggage-, glove-compartment, etc.
  • Select: land-coding.


    • Enable dashboard diagnostics:
  • Read oil pressure.
  • Read oil level.
  • Read brake fluid level.
  • Read engine temperature.
  • Read coolant level.
  • Read toothed belt tension.



    • Supported modules in the 944/964/968/993 (DT911 & DT944)
    944, 964, 968 and 993 has several modules which are all connected to the K/L line of the diagnostics bus. The modules are: Motronic, Climate control, PDAS(964-C4), Tiptronic, Airbags, Alarm system and ABS(993). DT911 supports all of these modules. DT944 supports a sub-set of these modules.

    Motronic 2.1:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Perform drive link tests: injectors (6x at 964/1x at 944/968), idle stabalizer, tank vent and resonance plate.
  • Read input signals: throttle WOT/idle, Airco, coding, MAF sensor, lamdba sensor, idle stab value, air/engine-temp., engine load/speed.
  • Read actual values: Speed, MAF, Lambda, Air-temp., Engine-temp, Spark, coding, etc.
  • Perform Knock registration.


    • Motronic 5.2:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Perform drive link tests: injectors, idle stabalizer, varioram, tank vent and resonance plate.
  • Read input signals: throttle WOT/idle, Airco, coding, MAF sensor, lamdba sensor, idle stab., air/engine-temp., engine load/speed.
  • Read actual values: temperatures, Vbat, MAF, speed, load, coding, timimgs, throttle, etc.


    • Airbags:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Read downtime.
  • Read date of crash.


    • Climate Control:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Read input signals: AC switch, defroster switch.
  • Read sensors information: footwell, defroster blower, temperatures.
  • Read actual values: Vbat, rear-temp., inside-temp., oil-temp., etc.
  • Perform drive link tests: mixing flaps, blowers, footwell, oil cooler, etc


    • PDAS:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Read input signals: full lock switch.
  • Perform drive link tests: bleed procedure, check transverse lock and check longitudinal locks.


    • Tiptronic:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Read input signals: kickdown switch, up/down shift, stop light, selection lever.
  • Read actual values: RPM, injection time, modulation pressure, gear, coding etc.
  • Perform drive link tests: solenoid 1/2, reverse relay, oil cooler blower, etc.


    • Alarm:
  • Read ECU identification.
  • Read error codes.
  • lear error codes.
  • Perform drive links: activate horn, turn signals, interrior lights, locks, etc.
  • Read input signals: switches in engine-, luggage-, glove-compartment, etc.
  • Select land-coding.
  • Select remote control.
  • Select car type.
  • Select 993-inside security.


    • ABS:
  • Read ECU identification.
  • Read error codes.
  • Clear error codes.
  • Perform drive links: activate abs warning lamp, pump relay, MV front left/right, MV rear etc.
  • Read actual values: valve relay, stop light switch, speed sensors, return pump.




    • Overview DT serie & features:

    DT928: Read faults: Clear faults: Input signals: Input signals active: Actual values: Actual values active: Drive links: Drive links active: Sensors: Additional:
    LH yes yes yes yes yes yes yes n.a. n.a. Idle stab. program
    EZK yes yes n.a. n.a. yes n.a. n.a. yes n.a. Knock count
    PSD yes yes n.a. n.a. n.a. n.a. yes n.a. n.a. -
    RDK yes yes yes n.a. n.a. n.a. n.a. n.a. yes trip info
    ALARM yes yes yes n.a. n.a. n.a. yes n.a. n.a. land coding
    AIRBAG yes yes n.a. n.a. n.a. n.a. n.a. n.a. n.a. date of crash, downtime


    DT911: Read faults: Clear faults: Input signals: Input signals active: Actual values: Actual values active: Drive links: Drive links active: Sensors: Additional:
    ALARM yes yes yes n.a. n.a. n.a. yes n.a. n.a. land coding, car select, security
    AIRBAG yes yes n.a. n.a. n.a. n.a. n.a. n.a. n.a. date of crash, downtime
    MOTRONIC 2.1 yes yes yes n.a. yes n.a. yes n.a. n.a. Knock count
    MOTRONIC 5.2 yes yes yes n.a. yes n.a. yes yes n.a. -
    CLIMATE yes yes yes n.a. yes n.a. yes n.a. yes -
    PDAS yes yes yes n.a. n.a. n.a. yes n.a. n.a. -
    TIPTRONIC yes yes yes n.a. n.a. n.a. yes n.a. n.a. -
    ABS yes yes n.a. n.a. yes n.a. yes n.a. n.a. -


    DT944: Read faults: Clear faults: Input signals: Input signals active: Actual values: Actual values active: Drive links: Drive links active: Sensors: Additional:
    ALARM yes yes yes n.a. n.a. n.a. yes n.a. n.a. land coding, car select, security
    AIRBAG yes yes n.a. n.a. n.a. n.a. n.a. n.a. n.a. date of crash, downtime
    MOTRONIC 2.1 yes yes yes n.a. yes n.a. yes n.a. n.a. Knock count
    MOTRONIC 5.2 yes yes yes n.a. yes n.a. yes yes n.a. -
    TIPTRONIC yes yes yes n.a. n.a. n.a. yes n.a. n.a. -


    DT999: Read faults: Clear faults: Input signals: Input signals active: Actual values: Actual values active: Drive links: Drive links active: Sensors: Additional:
    LH yes yes yes yes yes yes yes n.a. n.a. Idle stab. program
    EZK yes yes n.a. n.a. yes n.a. n.a. yes n.a. Knock count
    PSD yes yes n.a. n.a. n.a. n.a. yes n.a. n.a. -
    RDK yes yes yes n.a. n.a. n.a. n.a. n.a. yes trip info
    ALARM yes yes yes n.a. n.a. n.a. yes n.a. n.a. land coding, car select, security
    AIRBAG yes yes n.a. n.a. n.a. n.a. n.a. n.a. n.a. date of crash, downtime
    MOTRONIC 2.1 yes yes yes n.a. yes n.a. yes n.a. n.a. Knock count
    MOTRONIC 5.2 yes yes yes n.a. yes n.a. yes yes n.a. -
    CLIMATE yes yes yes n.a. yes n.a. yes n.a. yes -
    PDAS yes yes yes n.a. n.a. n.a. yes n.a. n.a. -
    TIPTRONIC yes yes yes n.a. n.a. n.a. yes n.a. n.a. -
    ABS yes yes n.a. n.a. yes n.a. yes n.a. n.a. -


    Bosch Hammer KTS300/KTS301
    There are two methods to read fault codes from the 928/944/964/968/993. The first, an oldfashion way is to read faultcodes with the check engine line, which is available on the diagnostics plug in your car. But the RDK unit does not support this kind of method to read fault codes, or to perform drive tests. The second method, the one which the Bosch Hammer KTS300/KTS301 is using, is much more powerfull. It communicates the same way like most diagnostics tools today: the ODBII-way. With this method, you are able to readout much faster faultcodes, but also much easier to perform drive tests and reading input signals. With this method you are able to read the RDK module.
    DT911/DT928/DT944/DT999 is using the same method as the Bosch Hammer KTS300/KTS301 and is able to offer you the same and even more features as the Hammer.