How can I test my ECU serial port?

[rightfoot]

Anyone know how I can check my ECU's serial port to figure out if it's live or dead.

I've bought three different cables/setups so far and not one of them gets a serial connection.
The Jim Wolf shop says I can send it back but I'd like to check it myself before doing anything else.

Thanks.

Mike

[300ZXttZMAN]

The ecu is not dead. Easy as that

Edit: unless it got wet or kicked!

[Ace2cool]

Idk Mark, could have just fried. Not unheard of.

Does the car run? Also, please start posting your tech questions in the technical forum.

[NolimitZ32]

If the check engine light/LED on ECU stays on or never turns on the ECU is dead, if the car runs, the CEL/LED turn on and off, and it will output codes (even if its code 55) when using the dial on the ecu itself than your computer, the cable or the actual consult connector plug (in the car) is the problem.

[300ZXttZMAN]

If the check engine light/LED on ECU stays on or never turns on the ECU is dead, if the car runs, the CEL/LED turn on and off, and it will output codes (even if its code 55) when using the dial on the ecu itself than your computer, the cable or the actual consult connector plug (in the car) is the problem.

Exactly ^

[300ZXttZMAN]

Idk Mark, could have just fried. Not unheard of.

Does the car run? Also, please start posting your tech questions in the technical forum.

Yes I agree completely but its very unlikely because you anton and I all know that there are soo many more variables that could be the problem..
I just really dont want him to buy a new computer plug it up then nothing changes. And now he is stuck with 2 computers and stll fighting the same problem....

Plus the car still runs from what I understand when he was describing the problem...

[rightfoot]

The ecu is not dead. Easy as that

Edit: unless it got wet or kicked!

I don't believe the ECU is dead since the car runs. I said I wondered if the serial port is messed up on it since I can't connect to it with anything. Either way, the question is how can I test the serial port.

[rightfoot]

Idk Mark, could have just fried. Not unheard of.

Does the car run? Also, please start posting your tech questions in the technical forum.

Yes, the car runs, with problems which I am not sure are related or not, in another post.
viewtopic.php?f=315&t=538678&p=6155827&e=6155827

I thought I did post in the tech forum.

[rightfoot]

If the check engine light/LED on ECU stays on or never turns on the ECU is dead, if the car runs, the CEL/LED turn on and off, and it will output codes (even if its code 55) when using the dial on the ecu itself than your computer, the cable or the actual consult connector plug (in the car) is the problem.

Yes, I can get the Normal reading from the LED on the ECU.

[rightfoot]

>I just really dont want him to buy a new computer plug it up then nothing changes.
>And now he is stuck with 2 computers and stll fighting the same problem....
>Plus the car still runs from what I understand when he was describing the problem

Yes, it runs. I have started having problems in the past few years, which may or may not be related. I posted the thread location in another reply here.

What I would very much like to do is to test the ECU serial connection to at least find out if it is dead and is why I cannot connect to it using three different consult setups so far.

I want to gain access to the ECU so that I can see if there is anything obvious. For example, the car is running very rich, to the point where the plugs are black with buildup and black smoke out the back when I hit the gas pedal. It would be nice to be able to maybe tune the richness back a little and see what happens.
Being able to get into the ECU, I could at least post some of the things I'm seeing.

[NolimitZ32]

So what code does the ECU show? Unless you have a nistuned ecu you wont be able to tune anything.

[rightfoot]

I can't recall now but it was what ever the 'normal' code is. 55 or something I think?
The manual says what the code should be and it was.

[rightfoot]

So what code does the ECU show? Unless you have a nistuned ecu you wont be able to tune anything.

Forgot to mention that it seemed to run well when I first did the upgrade. A while into it, I do recall starting to see black smoke now and then when I would hit the gas hard on takeoff.

[NolimitZ32]

In that case, as much as I hate to say this, time for you to grab the FSM and a multimeter and test the consult wires along with the o2 inputs and outputs and the tps, maf, & injectors while you're at it. thats the best and most conclusive way.

[rightfoot]

In that case, as much as I hate to say this, time for you to grab the FSM and a multimeter and test the consult wires along with the o2 inputs and outputs and the tps, maf, & injectors while you're at it. thats the best and most conclusive way.

Sorry, I just don't know all of the acronyms .
FSM, manual?
TPS?

The others I get .
Test the consult wires? The consult wires to me mean the wires that connect the consult tool to the ECU OBD connector and I'm sure that's not what you mean.

So do you mean find the wires to the ECU that are for say the MAF and see if there is a break in that. Then the fuel injectors, etc. I've tested for power at the injectors and there was. I did an inline test while it was running.

The MAF seems to work because when I pull the connector, it runs differently. I can test that again.

[NolimitZ32]

Tps=throttle position sensor
FSM=factory service manual
maf=mass airflow sensor
the consult wires woulr be the wires that run from the consult plug under the driver's side dash to the ecu (to make sure the wires aren't physically damaged.

If youve already tested the maf and injector wires and they're good you can move on the the rest of the system. I've always used the diagnostic procedures in the FSM to figure out problems, it can be tedious sometimes but it will almost always show you where the problem is. the FSM is available here on nico and through a google search. go into the EF/EC section and I belive page 42 is where the diagnostics start.

[rightfoot]

>Tps=throttle position sensor

That's the one that had me. FMS kinda sounded like manual and the others I knew .

>the consult wires woulr be the wires that run from the consult plug under the driver's side
>dash to the ecu (to make sure the wires aren't physically damaged.

Makes perfect sense. Those run into the ECU block so I'll need to find out which pins those run to. Be

>FSM is available

I have a physical manual but I sure would love a searchable PDF version. I bought one from a guy on ebay once and it was crap. All photocopies, fuzzy, can't search since it's just copies of the manual.
Being able to search would help a lot.

[NolimitZ32]

theres a link to it in general in one of the stickies or just google "300zx online service manual"