This might be of some use. Motronic Schematic
Note: The N122 and N127 info is wrong (see the link under the diagram)
March 21, 2009
Motronic Schematic
Note: The N122 and N127 info is wrong (see the link under the diagram)
March 20, 2009
Removal of the North America UrS4/S6 130 mph speed limiter.
Audi put the limiter in because they weren’t convinced that North Americans would put V-rated tires on their cars. The maximum rated speed for H-rated tires is 130 mph. Hence the speed limiter.
It is easy to remove this limiter. Naturally, this only applies to cars that will be on the track. We would never promote such outrageous speeds on normal highways.
YMMV
Coding plug (130mph speed limit)
In order to have speed limit set to 130 mph
you should bridge terminal 1 of coding plug to terminal 4 which results in terminal 38 of the ECU being connected to ground.
Coding plug can be found next to ECU in electronics box under the carpet in the
passengers footwell.
Whoever was looking for stock chip numbers and location, see inside
Bosch Motronic ECU FAQ from the S-cars.org archives (based on Jimmy Pribble’s older UrS4.com archives).
If it doesn’t come up to the ECU FAQ right away, just “search in page” for ECU FAQ and you will find it.
Link to one source of ECU repair
Steve Eiche of Shadetree Software in Colorado (Denver area) is an ECU guru and can resurrect many (but not all) damaged ECUs. Follow the link below.
Wiring photo of ECU (easy to read) and all its fuses and sensors…
From alpinab7′s post
__________________
New ECU connector pin-out with wire colours and comments
This should help if you are trying to track down a problem (electrical pun intended). You will still need a wiring diagram from the Bentley:
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 – Output to Fuel Pump Relay – J17 – BR/Y – ECU triggers the relay after it gets the G40 cam position sensor signal
4/55 – Idle Air Control Valve (aka Idle Stabilization Valve (ISV)) – N71 – W/Y the ISV is used to control the idle, e.g. when the air conditioning compressor comes on.
5/55 – Output (Fuel) Tank Breather valve N80 – 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-Mass Air Flow (MAF) Sensor – G70 – 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 Hall Sender – G40 – GY/R – signal wire – Not lack of signal = Blink code 2113 and the engine will not start
9/55 – Barometric sensor – G16 – 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- Ground for Lambda (Oxygen) Sensor – G39-BR/R
11/55 -Input from Knock Sensor No. 1 – G61- G/G – for cylinders No. 1, 2 and 3
12/55- Power Supply (+5V) out to Hall sender – G40; Throttle Potentiomenter (G69) 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
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- MAF – G70 – 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- Heated Oxygen (O2) Sensor – G39- G/G- input from sensor
29/55-Input from Knock Sensor No. 2 – G66 – W/W- for cylinders No. 4 and 5
30/55- Ground for ECU and ECU sensors – G/BK
31/55- Fuel consumption signal for trip computer – BL/BK – Note: only used in N.America on 92 spec cars
32/55-Output toTrip Computer Boost Pressure Gauge – Y/BL – Note: only used in N.America on 92 spec cars
33/55 – Waste Gate Frequency Valve – N75 – Y/R – also know 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 – 15A – Circuit Breaker S72
38/55-T6ag Coding plug -Pin 1-GY/W
39/55-T6ag Coding plug- Pin 2- GY/Y
40/55-Input from Engine Speed Sensor – G28 – V/BK – Also connected to Ch.28 in the A/C head (you can read out RPM in the A/C head)
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 -Gear selection input – Automatic only
43/55 – Not used
44/55 – Intake Air Temperature (IAT) Sensor – G42 – 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 – Engine Coolant Temperature Sensor – G62 – 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 Crankshaft Position Sensor – G4 – 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 Engine Speed sensor – G28 – GY/GY
50/55- Road Speed signal output (input?) to Instrument Cluster-G21-W/BL-signal also goes to Automatic Climate Control Head Channel 17 – which you can read out speed as well.
51/55- Not used for standard transmission cars – relates to shift point for automatic trans cars
52/55 – Idle Switch – F60 V/V- a microswitch inside the G69 throttle potentiometer that tells the ECU that the throttle is closed
53/55 – Throttle valve potentiometer – G69 – GY/GY the potentiometer on the throttle body that tells the ECU the degree to which the throttle body is open
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