SDMO V350C2 WILL NOT START . THE SCREEN SAYS ENGINE CAN BUS. WHAT IS THE PROBLEM AND HOW TO SOLVE IT. ALSO SAID CHECK CONNECTORS -ECU SUPPLY. THE SCREEN IS MICS TELYS 2 .THE ENGINE IS VOLVO TAD941

Sounds like similar problem I had with a 2004 Altima 2.5. Crank but no start. Ended up being a timing chain stretched out and tensioner pinching chain against case not allowing variable timing to work and throwing off cam and crank sensor signals.

great question, im ane ECU spirt. )EFI.
what country, nobody ever says, that but gee, the OBD varies buy
COUNTRY!
Ill pretend USA. /Canada.

In the USA the car has OBD2. and you need a scan tool that works
on 2002 cars.
what engine, some engines have different ECU. radical differ..
they had like 3 engines here, other countries 9.

the scan tools connects to the 16pin, OBD2 connector at dash.
i the car is Can-bus. it needs a can-bus tool, all new tools work on canbus but old ones never do. (i have them back to 1995 and know this)
NON comms and tool is ok, not wrong tool . diagnosis.

1. Pin 16 not at 12vdc, (blown fuse)
2. ECU dead, 99% of time blown fuse to EFI. test the fuses to all EFI parts. alldata.com wiring shows that.
3. bad wiring to the DCL connector (rare) or from there to ECU
4. yes, some crappy tools have no ground on both pin 4 and 5, buy a tool that has 2 pins there. OR it will fail on some cars. seen many POS ELM327 tools that do this horror, get a tool called, INNOVA 3160 and stop guessing, this tool works on all cars.
5. barrow, rent , or buy or ask any sharp mech top scan car , his tool works.
6. Fuses that look ok can IN FACT be bad, we never assume they ar good we test them. using either method, OHMS or 12vdc on both sides, is better. see? only the voltage matters, all else punts.
7. The 3.3l communicates on pin 1 and 2..

pin 2 is PCM/ECU. VPW signalling.
and is not can-bus, yet.
simular to this.
http://ww2.justanswer.com/uploads/FO/fordguy4u/2013-03-02_224407_a1.jpg


top right photos
http://www.diagnostics4u.com/uploads/asset_image/2_4.jpg


there you go, you tool must have VPW support on pin 2.

You will have to check each connector on the PCM for moisture and the wires for shaving. Fuel quantity info comes from the PCM via the PCI data bus. Moisture in one of the connectors could short the data bus out and the engine will not start and indicators go to zero.

check the control module on the diesel pump
run the fault codes

Sounds like a MAP inlet Manifold Absolute Pressure sensor fault. Symptoms of a faulty MAP

• Poor starting/erratic idling/engine stall - with the MAP not sending the correct inlet air pressure signals to the ECU, incorrect fuel injection volumes then result. The imbalance in the fuel/air ratio often leads to rough engine performance and poor starting and stall. The engine might be kept running at start up by pumping the accelerator pedal
• Sluggish performance/power ceiling - the engine may seem to perform normally in the lower rev range but will severely run out of power above about 3000 rpm

Poor fuel economy. The ECU tends to supply an over rich fuel mix to the engine in the absence of signal from the MAP resulting in very poor fuel economy. The reason for this is that if the MAP has no signal this ECU assumes 'no vacuum' = fully open throttle = engine is under load. To match this 'open throttle' signal the ECU increases the injection cycle to supply more fuel

How to Check? The MAP has three electrical pins, one for 12 volts (or 5 volts) reference, one for ground and the third (the middle one generally) is the 'signal' output. Put a voltmeter positive connector on the 'signal' pin of the connected socket (back probe by inserting a bit of wire). Apply suction to the vacuum input, even sucking on it with your mouth, should result in a measurable voltage output. At normal air pressure (open throttle) the voltage seen should be 0 volts. As vacuum is applied the voltage output should change to about 5 volts (throttle closed at idle). If no transition seen the MAP is faulty.

Your ECU is going bad and needs to either be replaced or repaired. That 'no check engine light for 20-30 minutes' is a common problem that tells it's an ECU problem.The ECU won't power the fuel pump and other relays until the check engine light illuminates on the dash.

Since this is 91, its likely that the original engine has been replaced, and various other mods have been done. Essentially you need ot figure out what the previous owner did, and either fix it or ignore it.

A common "trick" with the wiring is to change the MAF sensor (on the air filter can) around to get more fuel at high boost. Pull off the 8 pin connector and check for bent pins. Check for 5V (NOT +12v) on one of the pins, as this is the MAF sensor supply voltage.

Other issues are the coolant temp sensor (2 pin sensor with black? connector on the themostat housing) connection.

If the temp sensor is not properly connected, or the wrong sensor for the engine, it will be hard to start esspecially when cold.

If possible, verify what ECU is fitted. The 90-91 ECU has slightly different pin connections to the 92-94.

You may also have fuel pump relay issues. This is the large can in the center console, near the ECU.
Open the ECU and check the large electrolytic capacitors for leaks. Its a common problem, and there various people around who will replace them before they destroy the ECU board.


Check all the vacuum hoses for cracks and leaks. Check the hoses for the intercooler and up to the throttle body.

Have a look at www.lancerproject.ca for more information.

if it starts using ether, it suggests a clogged fuel filter. You need to know what the true psi value is across the fuel rail. you can rent kit from major auto parts stores. be it remembered that many cars nowfays have 2 fuel filters- one in tank and one on frame or firewall. a quick check is back pump air through your fuel line till you hear bubbling. recheck fuel pressure and note diffetence. if it goes up you probably icked up larger debris on the screen.

The connector on the ECU is faulty,The ECU is located on the passenger fender well under the hood,You can try to unplug,Clean and plug back in to see if that helps.

Check the large multi-pin connector in the electronics bay in the engine compartment. The bay is a fairly large black plastic box on the driver's side. Open it and disconnect the largest connector inside (one screw). Spray electrical contact cleaner on the pins and re-mate the connector. This worked on my '99 with the exact same problem. You can find other examples of this with a Google search. It may not solve your problem (could also be a wiring harness problem), but it is incredibly simple and worth a shot.