Details of tata indica /indigo diesel ECU

[Vin Diesel]

Hello,
In one of my earlier posts i disagreed with Tsk 1979 who had mentioned about a 32 bit processor in tata indigo diesel .i was under the impression that IDI engines dont need ECU .Tata has done a wonderful job by using a ecu for the fuel pump and a cost effecive way to taclkle the stringent emission norms.
I was wrong Tsk . found some details from indica users group. hope it will be useful .
Moderators pls post this in a appropriate forum

Type No---475 IDI Euro-3
Make------Lucas TVS
Primary Functions :---
1. Fuel pump injection timing control.
2. Glow plug pre & post heat control.
3. EGR system on-off control.

Secondary Functions :---
1. FICD (Fast Idle Control Device Control). This is
the device which
increases the rpm when the AC is switched on.
2. AC switch off at high Engine temperature and high
loading.
3. High altitude proportional control.
4. Fault detection & storage of trouble codes.

The ECU gets its inputs / information about Throttle
position, coolant
temperature, ambient temperature, engine rpm,
crankshaft angle & Injection
start from the following sensors on the engine :
1. Throttle Position Sensor or Fuel Lever Sensor :
This is a potentiometer connected to the fuel delivery lever which is
actuated when the accelerator
pedal is pressed. It sends a DC voltage to the ECU which is proportional to
the accelerator postition.
2. Temperature Sensor : This is a thermistor type of
sensor, monitoring thecoolant temp.
3. RPM sensor : Part of the alternator. Gives 3
voltage pulses for one revolution of the crankshaft.
4. Crankshaft Angle Sensor or Crankshaft Position
Sensor. This is moumted onthe flywheel housing, and provides piston TDC (Top
Dead Centre) information to the ECU, in the form of number of voltage pulses
per 90 degrees angle of rotation.
5. Needle Lift Sensor : This sensor is part of No. 4 cylinder fuel injector,
& sends a voltage signal to the ECU at the precise beginning of injection.


How it works :
Based on the inputs from these sensors, the ECU
controls the following units
through Relays, Solenoid switches & PWM control :
1. Glow Plug Heaters : These are for pre-heating the
cylinders. The ECUcontrols the glow plugs ON time based on ambient &
engine temperature.
2. Fuel Pump: Injection timing is controlleddepending on the position of
the accelerator pedal----timing is advancedautomatically at higher rpm. The
ECU controls a cam actuator inside the fuel pump,
based on a look up table stored in the ECU program ROM.
3. EGR : This is the Exhaust Gas Recirculation
system. Part of the exhaust
gases are mixed with the air intake to reduce temperatures inside the
cylinders to below 210 deg C., which sharply
reduces the formation of Nitrogen Oxides (Nox) in the exhaust, thereby
reducing harmful pollutants as reqd. by Euro / BS 2 & 3 norms.The EGR valve is
controlled by the ECU, & gets activated in the rpm band 1100 to 3000 rpm,
with small variations to compensate for engine temp & loading.
4. FICD : The fast idle control is used to increase
the idle rpm when the AC is switched on. The ECU activates the FICD through a
solenoid switch by monitoring the AC compressor clutch voltage.

The ECU also continuously monitors the engine
temperature, & switches offthe AC if upper limits are exceeded.
All the sensors are also monitored continuously, and
a fault or troublecode is stored in non-volatile memory in case of a
fault, & the Check Engine Light comes ON.

[Mpower]

Hey VinDiesel

This is great info man. Looks like they really did a lot to certify it for Euro 3. This is like taking half a step towards a full DI system. They should have just gone for it.

[tsk1979]

The AC cutoff at high temp is there in old indicas also. MY 2002 June V2 had the AC problem where AC would switch off when it was very hot. It seems that the thermostat in radiator was reporting incorrect temparature. Though in those generation cars it was no ECU, just a simple switch.

[Rehaan]

Great info VinD!

Didnt know about the EGR being handled by the ECU between 1100-3000rpm, i thought it was just a startup thing ....those evil environmentalists!

cya
R

[Surya]

That was pretty cool info and might be of use to anybody...
Thanks VinD.

Surya

[angelfire]

hey thats some great info man!!...well if its got a ECU..then it am sure it can tweaked for high perfmance....has anyone done it out there??

[porsche_fan]

They use the same funda for the BS-3 Version of the 483DL (Ex-Safari;Sumo Victa GX Turbo), which is also an IDI engine.....

[directinjection]

It seems that in order to achieve BSIII emission norms, even direct injection engines (ordinary, not common rail) require some level of electronisation of the fuel injection pump. The Ashok Leyland Managing Director recently told Auto Monitor (it's a sister publication of Overdrive) in an interview that Ashok Leyland had achieved BSIII norm in Leyland trucks by fitting them with electronic fuel injection pumps.

[sivasankaram]

Hi,
It is lot of information I have been struggling to get. Thanks for this, I also want to know whether TATAs sell a workshop manual for Indica. Will appreciate if you can provide the info.
Sivasankaram

[svsantosh]

siva, some thread you dug from from the earth- great search friend - sadly your question is NO, there are no such off the shelves manuals sold for any car in India sold in the last 10-20 years, simple reason, Monopoly of their service workshops...

[sivasankaram]

Originally Posted by svsantosh

siva, some thread you dug from from the earth- great search friend - sadly your question is NO, there are no such off the shelves manuals sold for any car in India sold in the last 10-20 years, simple reason, Monopoly of their service workshops...

Santosh I guessed so and you confirmed it. Thanks