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Discussion Starter · #1 ·
Hello guys, I am new to the forum, and I have a problem.

I am working on a jetta4 AKL engine that was recently installed after it had overheated badly. The engine was installed and now it does not start.

The engine that is newly installed is came complete the only change I made was changing the ring gear and throttle body plug as the one on the original harness had a different female plug but the wires are the same colour for colour.

It starts only when you introduce starter fluid via the intake manifold and immediately dies when the fluid is used up. I scanned for codes (I do not have VCDS) and got these: 00635, 00668, 00282 and 01087. Please see the attached image.

The most worrying for me is 00668, 00282 and 01087. Now, code 00668 in the RossTech website is listed as a power supply issue to the ECM and the code clearly says open circuit. I think I have a bad fuse or relay supplying power to the ECU. The immo is fine... I need help ASAP.

PLEASE HELP... SOMEBODY MUST COME ACROSS THIS BEFORE...

Sincerely
Sizwe
 

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Discussion Starter · #2 ·
One thing I have noticed is that the 00668 is present in the ECU and ABS module and the RossTech websites notes the following about TDCs: "When found in multiple control modules at the same time, it's most likely a common source (e.g. ground spot, battery, generator)."

Thanks guys in advanced timing馃ぃ馃ぃ
 

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Welcome to Vortex!

I have two thoughts on your situation.

Diagnostic Trouble Codes aside.
1) If the Engine Controller had no power, the engine could not run. Period.
2) The engine runs on Starting Fluid and then quits when the fluid is consumed. You have a fuel problem.

Here is how I would start.
Power to the fuel pump(s), pretty easy to check with a Voltmeter.
Test the Fuses? My best advice is to remove, test and re-install One Fuse At a Time.

fat biker
 

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Discussion Starter · #4 ·
@fat biker, thanks buddy. I will do that first thing in the morning. The fuel pump primes when you cycke the key on and off though.

I forgot to mention that THERE IS NO B+ TO ALL INJECTORS. I am so sorry for that I did not state that. So it kinda moves us to the ECU power side instead of the fuel side. I have found a diagram and I am currently studying it hut I will post it for a everyone to help.
 

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Discussion Starter · #6 ·
Welcome to Vortex!

I have two thoughts on your situation.

Diagnostic Trouble Codes aside.
1) If the Engine Controller had no power, the engine could not run. Period.
2) The engine runs on Starting Fluid and then quits when the fluid is consumed. You have a fuel problem.

Here is how I would start.
Power to the fuel pump(s), pretty easy to check with a Voltmeter.
Test the Fuses? My best advice is to remove, test and re-install One Fuse At a Time.

fat biker
Please check the above buddy. Thank you for getting back to me.
 

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The image I get of the wiring diagram is too small to be of use.
'for sure check any fuses in the circuit.
Remember, fuses blow (open) for a reason, so if you find a bad fuse and if replacing the fuse lets the engine run you are not home yet.
You need to find out WHY the fuse blew.

fat biker
 

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Discussion Starter · #8 ·
The image I get of the wiring diagram is too small to be of use.
'for sure check any fuses in the circuit.
Remember, fuses blow (open) for a reason, so if you find a bad fuse and if replacing the fuse lets the engine run you are not home yet.
You need to find out WHY the fuse blew.

fat biker
Here is a better picture...
 

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Discussion Starter · #9 ·
Here is a better picture...
Update: the fuses are alright and the fuel pump relay is alright. I paid close attention to Fuse 32 (injectors), fuse 10 (ECU), fuse 43 (engine management) and F29 (Electronic control unit, ignition) and when I crank the engine, power comes through them.

One question though: Is it normal for injectors not to get 12volts when KOEO for VW Jetta4s? It is my first VW. Normally, injectors get B+ when the key is on and are actuated by the ECU in line with the pulse signal from the crank sensor and cam sensor.

Also, I fitted the old throttle into the car as my machine cannot adapt the throttle that came with the secondhand engine and when I rescanned for codes all the codes were gone except for 00668 "Vehicle voltage terminal 30 open circuit".

Guys, can my peril be caused by a faulty ECU? I am running out of options and time.

Thanks in advanced timing
Mshibonium
 

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Discussion Starter · #13 ·
I expect that real Engine Controller failures are rare.
I would concentrate on the wiring around the fuel injectors.
So I thoroughly checked today and I found that THERE IS NO 5V REFERENCE VOLTAGE from the ECU to the CRANK sensor. This means that the ECU is a zombie. All the others have the 5v power, hall sender, throttle, mass air flow are all fine. I have confirmed through a wiring diagram that the wires to the crank sensor are okay. The wires to injectors are okay and I even grounded the ECU directly to the engine as the black wire to the crank sensor was not grounded. So after grounding it, and grounding the ECU, and after grounding the throttle, I still coukd not get 5v to crank sensor...

I have checked my powers and ground for the ECU- all are fine.

And it dawned on me that the crank sensor grounds via the internal circuit of the ECU which then switches on the 5v reference power and sends it to the crank sensor. That is why the injectors will never fire coz the ECU is not aware of the rotation of the engine. The tachometer moves close to 200rpm but it wont fire the injectors since there is no 5v reference power from ECU. Am I right guys?

I think it is safe for me to conclude that my ECU is faulty...

Thanks in advanced timing guys

Sizwe
 

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Your ECU may be bad.
I do not have the schematic for reference.
My first question would be how does the ECU handle generating its 5 volt reference?
Is there one source that is shared by all of the sensors?
Are there multiple 5 volt references internal to the ECU box?

Here's what I would do...
Provide an external 5 volt source to the Crank SEnsor and see how it goes.
Any of several ways to do this without a major production
Lab Supply, adjusted to 5 volts. No not everybody has this power supply lying around
5 volt "Wall Wart" type. Most every household has a few of these.
Small "prototype board", 7805 three terminal voltage regulator with a couple of capacitors, some wire and a couple of alligator clips.
 

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Discussion Starter · #15 ·
Your ECU may be bad.
I do not have the schematic for reference.
My first question would be how does the ECU handle generating its 5 volt reference?
Is there one source that is shared by all of the sensors?
Are there multiple 5 volt references internal to the ECU box?

Here's what I would do...
Provide an external 5 volt source to the Crank SEnsor and see how it goes.
Any of several ways to do this without a major production
Lab Supply, adjusted to 5 volts. No not everybody has this power supply lying around
5 volt "Wall Wart" type. Most every household has a few of these.
Small "prototype board", 7805 three terminal voltage regulator with a couple of capacitors, some wire and a couple of alligator clips.
Here is the schematic... Unfortunately I don't have a 5v generator or "wall wart" type of the same. I am a mechanic of the (shadetree type 馃ぃ馃ぃ馃ぃ) .

The throttle (purple arrow) shares the same ground with ECU, crank sensor (blue arrow).

Thanks in advanced timing馃ぃ馃ぃ馃ぃ
Sizwe
 

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Discussion Starter · #16 ·
Here is the schematic... Unfortunately I don't have a 5v generator or "wall wart" type of the same. I am a mechanic of the (shadetree type 馃ぃ馃ぃ馃ぃ) .

The throttle (purple arrow) shares the same ground with ECU, crank sensor (blue arrow).

Thanks in advanced timing馃ぃ馃ぃ馃ぃ
Sizwe
Regarding the ECU 5v reference to crank sensor, the power should be constantly there when KOEO.

Thanks in advanced timing 馃ぃ馃ぃ馃ぃ
Sizwe
 
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