EMS400 ECU pin-out

[c-ground]

CHAPTER ONE:

EMS 400 ECU pin out (terminal assignment)

Introduction: EMS 400 ECU from Siemens VDO has two sectors called ECU1 and ECU2, with 120 pin terminals in total. Only 45 are used for SVDO 4G13/15.

The following list shows the terminal assignment as:

::ECU terminal number (Wire color code) Assignment::

ECU 1 (black connector)
2 (B-Y) ignition switch-ST (M/T)
3 (G-Y) A/C compressor relay
5 (Bk) ground
7 (unknown*) post-cat O2 sensor heater power
9 (Bk) pre-cat O2 sensor heater power
10 (Bk) ground
11 (R ) power supply
12 (R ) backup power supply
16 (B-Y) pre-cat O2 sensor ground
17 (W) pre-cat O2 sensor signal output
18 (B-Y) ignition switch-ST & inhibitor switch A/T
19 (unknown*) post-cat O2 sensor ground
20 (unknown*) pre-cat O2 sensor signal output
27 (B-W) dual-switch for condenser fan relay
29 (L-Bk) ignition switch-IG
33 (W-R) power supply and fuel pump control relays
34 (Br-Y) purge control solenoid valve
35 (G-Bk) engine fan relay
37 (Y) unidentified
38 (G) unidentified
44 (G) A/C switch signal to A/C control unit
58 (Bl) unidentified
59 (Y-W) vehicle speed sensor
60 (W) unidentified

ECU 2 (gray connector)
63 (Y-Bl) injector #1
64 (Y-Bk) injector #2
65 (B-G) injector #3
66 (L-W) injector #4
67 (R-L) ISC servo motor power (+5V)
68 (Bk) ISC servo motor ground
69 (Bk) ground
71 (B-Y) ignition coil power transistor control
72 (B-R) ignition coil power transistor ground
78 (Y-G) coolant sensor power (+5V)
79 (Bk) IAT sensor and coolant temp. sensor ground
80 (Y) IAT sensor power (+5V)
81 (G) MAP sensor power (+5V)
84 (G) TPS ground
85 (W) TPS
87 (L) TPS
89 (G-R) TPS
99 (Bk) crankshaft sensor ground
100 (W) crankshaft sensor power (+5V)
104 (Bk) cam angle sensor ground
105 (Bk) MAP sensor ground
106 (W) cam angle sensor signal
108 (G-R) MAP sensor signal
112 (R ) cam angle sensor & TPS power
117 (unknown**) knock sensor
118 (unknown**) knock sensor

* Step III engines only
** 4G9 only
unidentified pin out – presumably to dash dials and indicators

Wire Color Code:
Bk = black
G = green
Y = yellow
R = red
W = white
L = light blue
Bl = blue

Disclaimer: information provided might not be 100% accurate. However, I spent 3 hours taking the ECU out for the Wire Color Code, and putting it back. Terminal Assignment is based on the official information gathered via undisclosable sources. Use this information at your own risk but please don't forget that you see this from Drex Chan first.

 

[alexklg]

my god... drex, you too free at home? hhaa... just kidding.

Great Information there. ;)

 

[c-ground]

hehe! Kinda..

Nothing to do at home last week so took the ECu out to check on it.

The function of some pin-outs are not confirmed yet. But the connections are correct. For example pin 11. It's not listed in the data sheet but it has a red wire so I presume that it's for power.

Those connected to the control relays.. not sure about the flow of the current as I don't have time to trace it one by one.

37, 38, 58 and 60 were not identified but believably for the dash dials, RPM signal, vehicle speed sensor ground, etc.

The pin-outs for the sensors are confirmed.

Need more time to refine the assignment.

 

[cuscostrutbrace]

May i know how did you check this

 

[c-ground]

for wire color code: take out the ECU and check one by one.
for the pin-out assignment: based on an undisclosable source. Well.. a manual basically.

 

[m1adam]

i want to upgrade my ems700 gen2 to use motec m48 ecu do i have to rewire ecu system or i can make use of the existing sensors in the engine and where can i get the default settings for my engine coz im a newbie i may damage the engine if i wrongly set the fuel and air mixture

 

[c-ground]

Sorry no experience in MOTEC. I am newbie too in ECU modding.

However, for SAFC, you can choose to either intercept the IAT or the MAP signal. IAT interception is more user friendly as it doesn't affect other parameters, however the gain is minimal (air density drops only ~5% for 20 deg C increase). Intercepting the MAP signal and adjust from there gives better gain but this also messed up the calculation for manifold vacuum, which will also affect the ignition timing.

In addition, the adjustment from the SAFC doesn't work during close-loop operation. It starts showing the effect during open-loop operation as the O2 sensor feedback is ignored.

However, a worry is that, the compensation off-set from the close-loop operation might be carried over to the open-loop operation by using new fuel & timing maps. This will minimize and might defeat any adjustment made through the SAFC.

You have been warned.

 

[c-ground]

CHAPTER TWO:
Operation of Various Sensors & Controls

1] Intake Air Temperature (IAT) Sensor:
- The IAT sensor converts the engine intake air temperature into a voltage and inputs it to the ECU, which then corrects the fuel injection rate, etc., based on the input signal.
- The +5V power in the ECU is supplied via a resistor in the unit to the IAT sensor. Via the sensor which is a kind of resistor (termistor), it's then earthed in the ECU. The IAT sensor resistor has such characteristic that its resistance decreases as the air temperature rises.
- The IAT sensor terminal voltage increases or decreases as the sensor resistance increases or decreases. Therefore the IAT sensor terminal voltage changes with the intake air temperature, decreasing as the temperature rises.

+5V --- resistor in ECU (pin 80, Y)---*----IAT sensor ----- internal ground (pin 79, Bk)

Voltage is measured between * and internal ground

T increase - R decrease - V decrease

Standard Key-on engine-off (KOEO) readings
T = 273K, V = 3.2 - 3.8V
T = 293K, V = 2.3 - 2.9V
T = 313K, V = 1.5 - 2.1V
T = 353K, V = 0.1 - 1.0V

The IAT sensor senses the intake air temperature in the air intake hose so that it may indicate a temperature different from outside temperature depending on the engine operation state.

2] Manifold Absolute Pressure (MAP) Sensor
- The MAP sensor converts the air intake plenum pressure to a voltage value and inputs it to the ECU. The ECU uses this signal and engine RPM to calculate the basic fuel injetcion timing. +5V of power (Vp = 4.8 - 5.2V) is supplied to the sensor from the ECU, and the sensor circuit earth is located in the ECU. The MAP sensor signal voltage (Vs) is proportioned (linear equation) to the intake plenum pressure.

+5V (pin 81, G) --- MAP sensor power --- internal ground (pin 105, Bk)

MAP sensor signal out --- + variable V (pin 108, G-R)*

Voltage is measured between * and internal ground

P increase - V increase

Standard Key-on engine-off (KOEO) readings
(also known as Barometric Absolute Pressure, BAP reading)
H = 0m, V = 3.7 - 4.3V
H = 1200m, V = 3.2 - 3.8V
engine idle reading: 0.9 - 1.5V

Together with the signal from the IAT sensor, engine RPM and several others, the MAP signal is used by the ECU to select the suitable fuel mapping for accurate fueling. This is called a "speed-density" system.

In addition to that, the ECU always measures the BAP (KOEO) from the MAP sensor before the engine is started. When the engine is started, the ECU calculate the manifold vacuum by:

BAP - MAP = manifold vacuum.

Manifold vacuum indicates the LOAD of the engine, which the ECU is based on to determine the ignition timing advance.

3] Engine Coolant Temperature (ECT) Sensor:
- The ECT sensor converts the engine coolant temperature into a voltage and inputs it to the ECU, which then control the fuel injection rate and fast idle speed when the engine is cold, based on the input signal.
- The +5V power (Vp = 4.5 - 4.9V) in the ECU is supplied via a resistor in the unit to the ECT sensor. Via the sensor which is a kind of resistor (termistor), it's then earthed in the ECU. The ECT sensor has such characteristic that its resistance decreases as the coolant temperature rises.
- The ECT sensor terminal voltage increases or decreases as the sensor resistance increases or decreases. Therefore the ECT sensor terminal voltage changes with the intake air temperature, decreasing as the temperature rises.

+5V --- resistor in ECU (pin 80, Y-G)---*----ECT sensor ----- internal ground (pin 79, Bk)

Voltage is measured between * and internal ground

T increase - R decrease - V decrease

Standard Key-on engine-off (KOEO) readings
T = 273K, V = 3.2 - 3.8V
T = 293K, V = 2.3 - 2.9V
T = 313K, V = 1.3 - 1.9V
T = 353K, V = 0.3 - 0.9V

If the fast idle speed is inadequate or the engine emits dark smoke during engine warm up operation, the ECT sensor is often faulty.

4] Throttle Position Sensor (TPS):
- The TPS converts the throttle position opening into a voltage and inputs it to the ECU, which then control the fuel injetcion, based on the input signal.
- The +5V power (Vp = 4.8 - 5.2V) in the ECU is supplied to the TPS. It flows through the resistor in the sensor and is earthed in the ECU.
- As the throttle shaft rotates from the idle position to wide open position, the resistance between the variable resistor terminal of the TPS and the earth terminal increases. As a result, the voltage at the TPS variable resistance terminal also increases.

Standard Key-on engine-off (KOEO) readings
idle: 5%
WOT: 100%

The TPS signal is more important in the control of automatic transmission than in the engine control (i.e. fueling & ignition timing). Shifting lock and other troubles will be caused if this sensor is faulty.

5] Idle Speed Control (ISC):
- The ISC servo has a built-in idle position switch, which senses whether the accelerator pedal is depressed or not, converts the changes into a high/low voltage and inputs the voltage to the ISC servo.
- A voltage is applied to the idle position switch from the ECU. When the accelerator pedal is released, the idle position switch is turned ON to complete the earth. This causes the idle position switch terminal voltage to go from low to high, and energizes the ISC servo, which opens the throttle valve.
- The idle throttle valve opening regulate the amount of air entering the intake manifold to sustain an idle engine speed.
- Conditions that changes the idle throttle valve opening are air conditioning activation, cold start and automatic transmission load.

Standard Key-on engine-off (KOEO) readings
accelerator pedal released: 0 - 1V
accelerator pedal depressed: 4V or more

When the ignition switch is turn to ON. The ISC servo is self-calibrated to the previously-learned idle throttle opening. The value is stored in the ECU and is continuously updated when a stable and suitable idle speed (800 +/- 100 rpm) is achieved during the operation of the engine. Do not depress the accelerator pedal when you turn the ignition switch from OFF to ON.

6] Crankshaft Angle Sensor (CAS):
- The CAS detects the crank angle (piston position) of each cylinder, convert it to a pulse signal and inputs it into the ECU. The ECU computes the engine speed and the intake air amount of each stroke and outputs the injector drive signal and injection command signal based on this signal.
- The +5V power (Vp = 4.8 - 5.2V) in the ECU is supplied to the CAS. It flows through the electromagnetic coil in the sensor and is earthed in the ECU.
- The sensor is placed near to a toothed target wheel or timing rotor made of ferrous metal, mounted on the crank pulley. When the "teeth" of the wheel pass the sensor, a distortion of the electromagnetic field occurs and this generates a pulse in the current.

+5V (pin 100, W) ---- CAS ---- internal ground (pin 99, B)

The engine can not be started without a signal from the CAS and the failure is usually caused by a defective harness.

7] Oxygen (O2) Sensor:

8] Injectors:

9] Ignition Coil:

10] Purge Control Solenoid Valve:

 

[rikeys]

you toooooo freee leh!
go make some babies...... :X-:

 

[c-ground]

you toooooo freee leh!
go make some babies...... :X-:

kanasai rikeys!:emoticon_U:

 

[m1adam]

yoo hoo i pening lalat with tis explanation, isnt that for mitsu EFI system anybody with motec knowledge i just want to increase my low end torque for my gen2 and the stock ecu gives high end torque so i need high rev to reach the torque band any info on piggyback ecu or sometin im desprate i need to b as gud as the mitsu the engine is gud bt lack torque only below the 2k rpm

 

[c-ground]

yoo hoo i pening lalat with tis explanation, isnt that for mitsu EFI system

As mentoned in the topic title, it's for the EMS400 which can be found on the 4G13/15/93 SVDO version produced after oct 2001.

Not applicable to EMS700 for the campro S4PH and S4PE.

Motec ECU.. maybe someone else in some other topic can help. Good luck!

 

[rikeys]

yo! you certified PHD lar (Permenant Head Damaged)

 

[cuscostrutbrace]

Motec is expensive but it is great,maybe u wanna try some lower cost ecu,they can do the same job as well.If you are using N/a engine daily driven average car,many of the motec features u will not use thus waste money to buy such expensive system.But if u have the money,go ahead.Motec is a good ecu to have.Try to increase the torque by changing exhaust system first.

 

[m1adam]

Can pls advise on lowercost ecu type and brand i would like to know i have checked lotsa exhaust shop they offer crap exhaust system for my gen2 i have tried out a few of my frens gen2 which has modded exhaust manifold the engine is a lot easier to rev compared to the standard bt i feel that the torque has decreased my standard exhaust settings has mo power where can i look for gud exhaust setup for my car plz advise is the hotbits exhaust system gud does it significantly increase performance coz R3 people brag a lot bout their R3 gen2 usin hotbits.