Announcement

Collapse
No announcement yet.

AAN T55 - ECU Connector Pin-out

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • AAN T55 - ECU Connector Pin-out

    Motronic Pin-out
    http://forums.quattroworld.com/s4s6/msgs/21009.phtml
    Our C4 UrS-cars have an AAN engine that is controlled by a Bosch Motronic ECU (computer). This AAN Motronic ECU has had a number of part numbers, depending on the location and year. Here is a list compiled by Dmitri ("prj") on the S2Forum (who has cracked most of the Motronic codes)

    "AAN Motronic ECU Part Numbers:
    551A early UrS4 with pseudo dizzy and 8k boost chip
    551AA UrS4 non-immo, Europe and America
    551B UrS4 same as 551AA, but auto
    551C UrS6 incorporates all software updates from RS2, different codebase, more diagnostics
    551D UrS6 same as 551C but auto (see photos at the end of this post)
    551E UrS6 has a small tweak to fuel on cold start
    551F UrS6 same as 551E but auto.

    At 551C, when the immo got incorporated, the RS2 codebase was merged as well. Yes, all are still 230hp DIN, 227 hp SAE), but many routines are rewritten. For example the rev limiter routine is different, the software code area in the boost/knock control unit is 200 bytes longer and so on."

    VAG calls the Motronic ECU the "J220" in device schematics, e.g. in the Bentley manuals. There are a number of inputs and outputs to this "J220" ECU, as listed in this diagram (Note: The N122 and N127 Power Output Stage info is slightly wrong in the diagram)(Also note the hyperlinks to more info in the pin-out list below the diagram):



    Here is a more graphic illustration of the devices that the ECU controls, i.e. the engine bay harness with device part numbers:



    Details on the passenger compartment-side of the Engine Harness, including the F96 Barometric Pressure Sensor and the above the ECU fuses is available in this pdf

    At some point, you might have a problem that requires you to check the Check Engine Light (CEL) fault codes, either by blink code or through a VAG tool. The list of code outputs is at SJM Autotechnik. As a result, you might have to check for continuity between the device and the ECU. For this, you will need information about what wire is connected to what device. This list is provided below, along with hyperlinks to information about those input and controlled devices. You might also want to visit the Engine Bay Device Map

    Here is the T55 ECU connector fully latched into place in the ECU T55 receiver.



    Here is the T55 with the metal bale rotated anti-clockwise to release the connector from the T55 receiver on the ECU, with the T55 connector being pivoted cloclwise on the two plastic pins at the left hand nose of the T55:



    Here is the AAN ECU with the unlatched T55 connector:



    ECU installation is the reverse of removal.

    If you need to check the ECU pins in the T55 connector, please consult this ECU pin connector removal/checking post

    Pin-Out for the AAN ECU (or Engine Control Module (ECM)) T55 connector
    ************************************************** ********************

    The AAN ECU connector has 55 pin positions. The pins are arranged in three rows. The longest row has 19 pins, Pins 1 through 19. Pin 1 is nearest the metal release lever on the harness connector. The middle row is Pins 20 through 37, with Pin 20 nearest the metal release lever. The last row is Pins 38 through 55 with Pin 38 nearest the metal release lever. Not all pins are used.



    The following are the Pins and their assignment. The information is taken from the Robert Bentley manual with comments based on VAG service manual 143 (VAG143) information and some experience.

    The Letter/Number, e.g. N71, are for the devices that are either being controlled or are sending a signal to the ECU. The Letter/Letter code is the wire colour code. Not all pins are used - especially on the standard transmission cars.

    Wire Colour Codes used in the pin-out list below:

    BK = Black
    BL = blue
    BR = Brown
    CL = Clear
    G = green
    GY = gray
    LT G = Light green
    OR = orange
    R= red
    V = Violet
    W = white
    Y = Yellow

    Examples:
    W/V = white with a violet stripe
    R/BK = red with a black stripe

    Pin - Assignment - Device Code - wire colour - Comment (if any)

    1/55 - Output to Power Output Stage - N122- G/W- for Coil No. 1 (N122 Pin 4/4)

    2/55 - Output to Power Output Stage - N122 - V/BK - for Coil No. 2 (N122 Pin 3/4)

    3/55 - ECU-controlled ground for the J17 Fuel Pump Relay - BR/Y - ECU triggers the relay after it gets the G40 cam position sensor signal by pulling the J17 fuel pump relay to ground through pin 3.

    4/55 - ECU-controlled ground for the N71 Idle Air Control Valve (aka Idle Stabilization Valve (ISV)) - W/Y - the ISV is used to control the idle, e.g. when the air conditioning compressor comes on or coming to a stop.

    5/55 - ECU-controlled ground for the N80 Evaporative Emissions Control Valve - W/R- Controls the evaporative emissions frequency valve - N80 - to cycle evaporated fuel vapours back in to the engine (NOTE: Bentley shows this as T55/3 on page X57 - presumably in error) VAG143 has it as N80.

    6/55-Connection to A/C Control Head -E87- G/Y - Used to shut off A/C for up to 12 seconds when throttle is opened rapidly at speeds under 7 kph and shut off A/C for up to 3 seconds when in first gear and throttle position is at 65 degrees or more (full load) Ref: VAG143.

    7/55-Input from G70 Mass Air Flow (MAF) Sensor - G/W - the MAF allows the ECU to know how much air (by mass) is heading to the cylinders so it can adjust the fuel, boost and timing to suit the conditions

    8/55- Input from G40 Cam Position Hall Effects Sender - GY/R - signal wire - Note lack of signal = Blink code 2113 and the engine will not start. J17 fuel pump relay is not triggered.

    9/55 - Input from F96 Barometric pressure/altitude sensor - GY/BK - provides a signal to the ECU to help control boost at higher altitudes - between 1000 and 4000 meters - prevents the turbo from spinning over 155000 rpm.

    10/55- One of the Grounds for the ECU -BR/R

    11/55 -Input from G61 Knock Sensor No. 1 = G/G - for cylinders No. 1, 2 and 3

    12/55- Power Supply (+5V) out to Hall sender - G40; G69 Throttle Potentiomenter and Altitude Sensor (F96) - R/R -

    13/55- Output to Data Link connector "L" for diagnostics - W/R

    14/55-Ground for Fuel Injectors (N30-83)- BR/W - ground on intake manifold

    15/55-Not Used

    16/55 - Output control signal to Fuel Injector No. 5 - N83 - W/BL

    17/55- Output control signal to Fuel Injector No. 2 - N31 - W/BR

    18/55- Constant power supply to ECU J220 - R/R- from power terminal 30 (+12V) Fuse S26 (5A) - passenger footwell as shown HERE, in this above ECU fuse panel call-out post). This constant power also feeds the Holding Relay for its work during start-up and shut-down.

    19/55- Ground from the ECU for various ECU controlled devices - BR/R - to intake manifold

    20/55 - Output to Power Output Stage - N127 - BK/Y - for Coil No. 4 (Note - some early versions of the Bentley have this as Coil No. 5 - but this is wrong, it is 4 - check it yourself) - VAG143 has it correct.(N127 connector Pin 4/4)

    21/55 - Output to Power Output Stage - N127 - BK/W - for Coil No. 5 (Note - some early versions of the Bentley have this as Coil No. 4 - but this is wrong, it is 5 - check it yourself)- VAG143 has it correct. (N127 connector Pin 3/4)

    22/55 - Data Link Connector - W/BL - linked to Check engine light (Malfunction indicator lamp) - also used in the blink code check.

    23/55 - Output to Power Output Stage - N122- BK/GY signal for Cyl #3 Ignition coil (N122 connector Pin 1/4)

    24/55- Power Ground for "actuators" other than injectors - Not found in Bentley, presume BR/R, ground to intake manifold

    25/55- Mass Air Flow (MAF) Sensor (aka - hot-wire air volume meter) - G70 - G/V- Burn off signal from ECU - every time the engine is switched off, the hot wire is heated to 1000 deg C for one second to keep it clean

    26/55- G70 MAF - R/BK- "Reference voltage, earth (ground) in"

    27/55- Switched Power to ECU from power (+12V) - BK/G - from Terminal 15 under the knee bolster - 15A circuit breaker, BK in BK/G out - S64

    28/55- Input from G39 Heated Oxygen (O2) Sensor - G/G- This is the single black wire coming out of the O2 sensor to a single spade connector in the harness at the connector rack. The two white O2 wires are for the heater and are not run through the ECU.

    29/55-Input from G66 Knock Sensor No. 2 - W/W- for cylinders No. 4 and 5

    30/55- Ground for ECU and ECU sensors - G/BK (See details with a listing of the seven devices grounded through Pin T55/30)

    31/55- Fuel consumption signal for trip computer - BL/BK - Note: only used in N.America on 92 spec cars (But still available at Connector Stn.2 )

    32/55-Output to Trip Computer Boost Pressure Gauge - Y/BL - Note: only used in N.America on 92 spec cars (But still available at Connector Stn.2 )


    33/55 - Ground for N75 Waste Gate Frequency Valve - - Y/R - also known as the charge pressure control actuating valve - lets the ECU control the boost - by dumping excess boost through the waste gate

    34/55 - Output control signal to Fuel Injector No. 3 - N32 - Y/BL

    35/55 - Output control signal to Fuel Injector No. 4 - N33 - Y/G

    36/55 - Output control signal to Fuel Injector No. 1 - N30 - W/V

    37/55-Switched +12V for all 5 Fuel injectors (N30-N83) and MAF (G70)- BK/R - Provides ignition-on power to injectors and MAF during starting conditions and then power to the MAF for the hot-wire burn-off after the ignition is turned off all via a "Holding Relay" in the ECU. (Main power to the injectors and MAF comes through the J17 FP relay via pin 87A and the S72 thermofuse after the engine is started).

    38/55-T6ag Coding plug -Pin 1-GY/W

    39/55-T6ag Coding plug- Pin 2- GY/Y

    40/55-OUTput from G28 Engine Speed Sensor - V/BK to T6a/1, a green connector in Connector Station 2 in the passenger side kick panel where it changes to a green/blue wire that goes to T26/22 of the instrument cluster and then on to the G5 Tachometer. Also connected to Ch.27 in the A/C head (you can read out RPM in the A/C head) Link to Climate Control Diagnostics

    41/55-Signal from A/C control module -W/W - signal used by ECU to increase idle speed through ISV control when A/C compressor is activated (actually just maintains the idle speed when the extra load from A/C compressor is added to the system during idle)

    42/55 - (brown/green)- Gear selection input,e.g. P or N, - Automatic only - if an Automatic ECU is used in a manual trans application this wire needs to be grounded out to gives a 0 in the 4th position in VAG-com measuring block 005. It's default without being grounded is 1 = no start. (Thanks to "MG" on the S2forum for this info)

    43/55 - Not used (*might* be Autotrans related??)

    44/55 - Input from G42 Intake Air Temperature (IAT) Sensor - BR/BL - the ECU uses this signal to dial back timing (and power) to prevent pinging if the intake air temp is too high

    45/55 - Input from G62 Engine Coolant Temperature Sensor - GY/BR - the one at the back of the head that the AAN ECU uses to figure out if the A/F should be enriched because the engine is cold.

    46/55- Not used

    47/55- Input from G4 Crankshaft Position Sensor - V/V - used by the ECU to control ignition and fuel injector timing

    48/55- Combined ground through ECU for G4 crankshaft position sensor and the G28 engine speed sensor - R wire from G4 and BL wire from G28

    49/55-Input from G28 Engine Speed sensor - GY/GY -allows the ECU to figure out the engine RPMs and make the required decisions

    50/55- Road Speed signal input from the Instrument Cluster Speedometer -G21-W/BL-signal - also goes to Automatic Climate Control Head Channel 17 - which you can read out speed as well, the Servotronic Control Module, the cruise control module and the UrS4 lockable rear differential controller (under the rear seat so it can dis-engage the rear diff lock at 15 mph (25 kph)). More details about the white/blue wire and where its branches go is available HERE. More info about the G22 Vehicle Speed Sensor (VSS) 012409191D and G21 Speeodmeter . The ECU uses this road speed signal to know that the vehicle is moving so that when throttle position switch (Pin 52/55) is indicating closed but the vehicle is moving, the ECU can shut down the injectors to save fuel while coasting. Conversely, if the road speed is zero and throttle is closed, the ECU knows that this is the idle condition and it keeps the injectors active.

    51/55- Not used for standard transmission cars - relates to kick-down shift point for automatic trans cars. Third digit in VAG-com measuring block 005. Normally "0" until kick-down with Autotrans when it goes to "1". (Thanks to "MG" on the S2 forum for this info)

    52/55 - Signal from F60 Idle Switch -V/V- a microswitch inside the G69 throttle potentiometer that tells the ECU that the throttle is closed. With this signal and the Road speed signal on Pin 50/55, the ECU knows that the car is either idling at a stop or coasting throttle closed and decides how to handle the injectors accordingly.

    53/55 - Input from G69 Throttle valve potentiometer - GY/GY the potentiometer on the throttle body that tells the ECU the degree to which the throttle body is open, which helps it compute "load".

    54/55- Not used for standard transmission cars - relates to automatic trans cars

    55/55- Output to Data Link connector "K" for diagnostics - G/R

    As mentioned in the 18/55 ECU power description, there is a fuse panel above the ECU, as shown below. Details about this panel are shown HERE, in this above ECU fuse panel call-out post)

    UrS4 Panel:

    Thanks to Jamu (EmeraldUrS4) for the base photo

    UrS6 Panel:

    Thanks to DaTrem for the base photo

    Here is some info on the ECU in a RHD car, in this case a 1996 UrS6 with Autotrans:

    Accessing the RHD UrS ECU


    Base photo courtesy of Popdemonic

    Here is the above-the-ECU fuse panel and the autobox computer, connected to the Motronic engine ECU at pins T55/42, 43, 51 and 54:


    Base photo courtesy of Popdemonic

    Here is the Motronic ECU showing the 551D Part No.:


    Base photo courtesy of Popdemonic

    Details on the T55/30 common device ground:

    Sever wires enter the common crimp located inside the T55 ECU connector. 5 of these wires are Green/Black, one is yellow and one is brown. The G42 IAT is one of the green/black wires.

    A single green/black wire exits the common crimp and runs to the T55/30 pin.



    The seven devices are, left to right,

    1. G61 knock sensor, 2. G66 knock sensor, 3. Idle switch/throttle potentiometer, 4. F96 Altitude sensor, 5. G62 engine coolant temp sensor, 6. G42 Intake air temp sensor and 7. Coding card for trip computer (probably regardless of whether the trip computer is installed or not).


    This *will* be on the exam.

    Thanks to those who posted the diagrams used in this post.

    Attached Files
    Last edited by UrS4boy; 9th September 2016, 17:40.
    RS2'd 93 UrS4 5 spd sedan
    94 UrS4 V8 6 spd manual avant

  • #2
    Good info
    93 S2 Avant Parting
    91 URQ RR
    02 A4 tdi Avant

    Comment


    • #3
      11-Input from Knock Sensor No. 1 - G61- G/G - for cylinders No. 1, 2 and 3

      Do you know what voltage the knock sensors output to the ecu ?

      S2 Coupe fully built.
      10.9 1/4mile 0-100 in 3.5secs
      Precision 6262 turbo
      The Green Monster

      Comment


      • #4
        Originally posted by Faheemo View Post
        11-Input from Knock Sensor No. 1 - G61- G/G - for cylinders No. 1, 2 and 3

        Do you know what voltage the knock sensors output to the ecu ?
        It's basically an microphone, so I think (don't know actual voltage) it's below 1v

        Sau
        200 20vt 88' 3b, human carrier
        CQ typ85 with AAN inside, see project blog at http://kwlw.blogspot.com

        Comment


        • #5
          Pin No. 6 info needs to be edited to read:

          6-Connection to A/C Control Head –E87- G/Y –Used to shut off A/C for up to 12 seconds when throttle is opened rapidly at speeds under 7 kph and shut off A/C for up to 3 seconds when in first gear and throttle position is at 65 degrees or more (full load) Ref: VAG143.
          RS2'd 93 UrS4 5 spd sedan
          94 UrS4 V8 6 spd manual avant

          Comment


          • #6
            What can be the cause when the ECU sees engine speed, Vag Com shows RPM but the instrument cluster not? We tried 2 different clusters but still no RPM. What cable goes from the ECU to the cluster?
            Go Holset or Go RS4

            Comment


            • #7
              really nice info...!!!

              Comment


              • #8
                Originally posted by Billman View Post
                What can be the cause when the ECU sees engine speed, Vag Com shows RPM but the instrument cluster not? We tried 2 different clusters but still no RPM. What cable goes from the ECU to the cluster?
                What car?
                If S2 - look for green/blue cable, going from engine loom to dash loom through black connector T10 pin 7.

                If AAN car - it is brown/red through T6c Red pin 1.

                Comment


                • #9
                  Updated AAN Motronic ECU device list and T55 pin-out

                  Originally posted by caterpillar View Post
                  really nice info...!!!
                  Wow. That must have been one of the earliest posts I made here in 2007. I have moved well beyond that point. Here is the latest version of that T55 AAN ECU connector pin-out (with hyperlinks to info about each of the devices to which the ECU is connected):

                  http://forums.quattroworld.com/s4s6/msgs/21009.phtml
                  RS2'd 93 UrS4 5 spd sedan
                  94 UrS4 V8 6 spd manual avant

                  Comment


                  • #10
                    Originally posted by Billman View Post
                    What can be the cause when the ECU sees engine speed, Vag Com shows RPM but the instrument cluster not? We tried 2 different clusters but still no RPM. What cable goes from the ECU to the cluster?
                    The G28 engine speed sensor signal enters the ECU on pin 49 as a blue wire:



                    EDIT: It goes through the ECU, is utilized as needed, and a signal to the G5 Tachometer emerges on Pin T55/40 as lilac (violet/purple) wire and as _ShurikeN noted, first going through a T10 connector on pin T10/7. It emerges from the T10 as green/blue wire and heads to the instrument cluster at pin T26/22. You need to check for continuity, broken wires and/or corrosion in the connectors, e.g. the T10.





                    Diagrams found in the Technical section of S2Central.net
                    Last edited by UrS4boy; 8th May 2014, 00:27.
                    RS2'd 93 UrS4 5 spd sedan
                    94 UrS4 V8 6 spd manual avant

                    Comment


                    • #11
                      Originally posted by _ShurikeN View Post
                      If AAN car - it is brown/red through T6c Red pin 1.
                      I think you have the Speedometer and Tachometer confused (maybe the English/German translation?). What you say is correct for the speedometer, not the tachometer (rev counter).

                      Connector Stn 2 info: http://forums.quattroworld.com/s4s6h...s/209044.phtml

                      The G28 Engine Speed Sensor on the edge of transmission, above the flywheel ring gear, sends its signal to T55/49 on the ECU in a Grey wire. The ECU uses and processes this signal appropriately to control fuel, timig and boost. It also sends a signal to the G5 tachometer in the instrument cluster. This G5 signal leaves the ECU on pin T55/40 (trace [79]) as a violet/black wire, goes through a T6a connector (as Pin T6a/1) (a green 6 pin connector in Connector Station 2 (passenger kick panel)) and emerges as a green wire (trace [79]). This green wire enters the C4 UrS instrument cluster on trace [174] and instrument cluster pin T26a/12.

                      If you have tachometer problems on your UrS, make sure that you have continuity between the G28 and the T55/49 ECU pin and between the T55/40 ECU pin, the T6a/1 connection and the T26a/12. If those show up good, you might have problem on the instrument cluster printed circuit board (cold joint/cracked trace that is often fixable).

                      BTW, the [578] destination on the [80] trace is the Automatic Climate Control head, i.e. the reason you can read the RPM on Channel 28 of the Climate Control Diagnostics





                      G4 and G28 info: http://forums.quattroworld.com/s4s6/msgs/20986.phtml
                      Last edited by UrS4boy; 8th May 2014, 04:55.
                      RS2'd 93 UrS4 5 spd sedan
                      94 UrS4 V8 6 spd manual avant

                      Comment


                      • #12
                        Where is the T6a to be found?
                        Go Holset or Go RS4

                        Comment


                        • #13
                          C4 UrS Connector Stn 2 info

                          Originally posted by Billman View Post
                          Where is the T6a to be found?
                          C4 Connector Stn 2. Passenger side kick panel. Green:

                          http://forums.quattroworld.com/s4s6/msgs/209044.phtml

                          RS2'd 93 UrS4 5 spd sedan
                          94 UrS4 V8 6 spd manual avant

                          Comment


                          • #14
                            Thank you very much. A
                            s it has been said many times your contribution and knowledge In the S community is GREAT!
                            Go Holset or Go RS4

                            Comment


                            • #15
                              Originally posted by UrS4boy View Post
                              I think you have the Speedometer and Tachometer confused
                              Yes, my fault. Sorry for inconvenience.

                              Comment

                              Working...
                              X