TrboSpdAnt

iTrader: (5)

I've been racking my brain and trying to wrap my head around this one and now I need some outside help:

So I've been getting this damned Hold.58 - Barometric Absolute Pressure Sensor - code since I don't know when. Nothing on the forum eludes to how it's been solved. Three days ago I went through and ripped every stinking vacuum line out of that engine and ran a complete reduction and STILL nothing.

I *FINALLY* tracked down the "cause" of the infamous 'Hold.58' code and the FSM shows that the circuit is directly wired from plug 2C(INPUT) on the PCMT (trans comp) to 2D on the PCME (ECU) [FSM Workshop Manual- pg. K-226 (pg. 763 in Adobe Reader)].

Apparently it completely JUST a matter of wiring.

Great. So I wasted a few hours yanking lines and ripping out hard-pipes, for no reason... Whee.

Following the gimpy-*** flowchart, I went through every test that is in the book and it's final remedy is to change out the comp.

So I did....

Both of them.

STILL have the ******* code! WTF?!!?

Only thing I can figure is to straight-wire plug 2C from the trans PCM to 2D of the ECU, since that's what the FSM shows, anyhow.

Help.... Please? Somebody?

TrboSpdAnt

iTrader: (5)

60 views an NO ONE has any idea WTF I'm talking about?

yay.

DaleClark

iTrader: (55)

I think you're going to have a problem with this one as most guys have manual trannies and people that DO have automatics aren't as hardcore about figuring out problems. They'll either ignore the problem or do a manual swap.

Wish I could help, I know ZERO about FD automatics.

Dale

ploplen

Do you have the barometic pressure code on the PCME? Check for continuity between the PCME and PCMT to see if the wiring is intact.

TrboSpdAnt

iTrader: (5)

Hm... You know, I'm not really sure which end is chucking the code. From the way pg.226 looks, in the FSM, either end could be throwing it.

As far as a continuity check, I've checked the voltage, but don't remember reading anything, at either source.

Other than that, what's a suggested way to go about checking it?

Sgtblue

iTrader: (16)

Or maybe replace the sensor?

TrboSpdAnt

iTrader: (5)

The sensor? You mean the boost reference sensor? You know, I thought of that, but the FSM - oddly enough - doesn't show **** in the circuit; just PCME to PCMT, direct.

Odd that that would prevent the car from starting... When I get back in, I'll do a 'disconnect' test, but since I was referencing the FSM, I don't know HOW that's supposed to work.

TrboSpdAnt

iTrader: (5)

Disconnect test SHOULD'VE at least thrown SOMETHING... Hm. Even if the sensor's bad, SOMETHING should be different when it's not connected!

*shakesfist*

ploplen

Now I think things are getting confused. The boost pressure sensor is one thing, the barometric pressure sensor is on thing. The boost pressure sensor measures the pressure after the throttle. The barometric sensor measures the atmospheric pressure. The barometic sensor is bolt on to the PCME. Therefore only one wire between the two computers.

Did you try to disconnect boost pressure sensor? That should not affect this problem.

If you check continuity between the terminals you will now that the cable is OK.

TrboSpdAnt

iTrader: (5)

LOL. No, I didn't check the BRS... That's what I thought he was talking about. I was fairly certain the other is in/ directly related to the ECU.

What page did that come out of?

It almost HAS to be the wiring, since I not only swapped out the PCMT, but ALSO the ECU, proper (PCME).

As far as checking continuity, it's just a matter of setting the meter on [?] and check from pins PCME(2D) > PCMT(2C) and read the output? Can't remember - though I'm pretty sure - is there's an actual setting for 'Continuity' on the meter...

Banzai-Racing

iTrader: (11)

Continuity setting is the one that "beeps" when the probes touch each other.

There should be 2V- 4.5V at pin 2D on the ECU with the key in the on position. same voltage should be at the trans ECU pin 2C

You are saying that the car will not start? Does the ignition turn over? The barometric pressure sensor in the ECU will not prevent the car from starting.

The Auto trans guys are becoming more "hardcore" by the second, now that they can install the Power FC with our adapter.

TrboSpdAnt

iTrader: (5)

Turn key, 'Hold' flashes, starter spins... No fire.

The only code that it's throwing is 58.... Starts fine, when it doesn't. Correlation? I think so, but *shrug*

When the car DOES start, and you drive it, maybe 5minutes after parking (but idling) the car just goes *plik* and turns off... As though you were in the car and turn it off, via the key.

ploplen

Page F12 in the workshop manual, or F11 in serivce highlights

Agreed

Either it has a special mode for check continuity or you can set it to resistance. The resistance should be low if there is continuity and infinite if there is not.

Yes

Banzai-Racing

iTrader: (11)

What type of aftermarket electronics are in the car, if any?

Alarm system, turbo timer, etc.. anything of that nature that can effect the starting system?

TrboSpdAnt

iTrader: (5)

Uhm.... Other than headunit and amp? AN HKS Turbo Timer. That's it, and THAT I installed, rectifying the wiring (All it was was the HKS jumper harness from the TT to the ignition solenoid, anyway; literally plug and play.)



I yanked the Alarm system (no change in symptoms/ consistency before and after the alarm came out), and I don't believe there's anything else.

Banzai-Racing

iTrader: (11)

You need to understand the the "plik" off, has absolutely nothing to do with the barometric sensor. Remove the turbo timer from the ignition harness. See how that effects things. It does not matter if it was plug and play you could have a faulty unit.

TrboSpdAnt

iTrader: (5)

That's what I meant about the TT: No change whether it was installed or not. I was thinking the same thing, but when I disconnected it, it still did the same thing... So I just reconnected it.

I wasn't sure if it had any correlation, but since it did the same thing, regardless of the TT's installation state, I figured it didn't and left it in.

What would cause the 'plik?' Like I said, it's as though it were killed via the key. Mebbe ignition-related, since it doesn't bog and/ or chuff itself out?

Basically, we have two different pissues: One being the '58' code / getting the car STARTED, and the other being PLIK.

Greeeeeeeeaaaaaatttt.

I need to charge the client a fxckin vital organ.

Banzai-Racing

iTrader: (11)

The code 58 is a side effect of the real issue, which is that your ECU is getting intermitent power or ground.

Here is the deal, you can plug a manual trans ECU into an Auto car and it will start every time, even though it is incapable of sending the barometric signal to the PCM.

The code is a PCM code only, all it means is that the ECU is not sending a signal. This means the ECU is not turning on for some reason. This is why the car is not starting.

Now that you have ruled out the TT, the next most logical place to look is the EGI main relay. It is a simple coil winding, corrosion can build up inside and cause all kinds of issues.

TrboSpdAnt

iTrader: (5)

Going to check that out, today. I'll check the grounding, to the ECU and the continuity, as well.

Hopefully that'll clean up the act.

EGI Main Rely; big yellow relay in main fuse-box, by battery, driver's side, under-hood? Gotcha.

TrboSpdAnt

iTrader: (5)

OOG. Work's been crazy. Haven't even LOOKED at the damned car, yet.... Client's going CRAZY trying to decide on plan of attack.

LOL. They asked if I knew anyone interested in buying (Now the turd's got an M5... Cause t's SOOO much cooler.

TrboSpdAnt

iTrader: (5)

Okay.

So I FINALLY got around to getting my hands back on the 7 to check voltages. Check this freaky **** out.

<insert 'Twilight Zone' theme, here>

Continuity (in ohms): 1.5@200 (damned cheap-***, 'Harbor Freight' Multimeter - No 'continuity' function setting);
PCM.2C: 2.9v;
ECU.2D .0fucking1v

WHAT!?!? I thought that there wasn't any way for THAT to happen.... It was my impression that 2D fed 2C, and the voltages should be the same-ish.

As far as the relay goes, it's lookin kinda oxidized, so I'll go pick up both that one and the Main Circuit relay, tomorrow.

How should I proceed, now!??!

ploplen

Strange with the different voltages. Did you use the same ground when measuring the voltages. If one ground is bad that would explain the difference. 1.5 ohm is a very small resistance, you have continuity.

Cleaning those relays seems wise.

TrboSpdAnt

iTrader: (5)

Yup. Same ground (pass. door hinge-pin).

I thought it REALLY odd when I went from checking voltage to ohms and having such a MASSIVE jump in the reading.

How is it I can get a solid 2.9v at the PCM when the other end of the SAME WIRE show no power, yet great continuity!??!?

TrboSpdAnt

iTrader: (5)

New stuff:

So I did the direct wiring option and piggy-backed a wire, all of 4" long, from 2C to 2D... Oddly enough, the error is... Still there, but voltage is on the nose.

HOWEVER! When I tried starting it... It actually TRIED to fire... Then I realized that both the EGI and fuel relays were fucked, so that was a lost cause.

Won't have those bastards until Tuesday, per Mazda.

Anyone got 'em close than that, in N. Cent. FL?

TrboSpdAnt

iTrader: (5)

So... here's one for the record books (l'll post a more concise version, tomorrow, or so):

I ran a direct wire from the 2C terminal to the 2D; found out that the relays were shot and went to see "The Electrician" (No ****, that's actually what we call him) and he checked the pair of relays and said that the EGI was fine (though I would say otherwise, by simple, visual, test), but that the Main Circuit Relay was shot.

He gave me a replacement and sent me on my way.

I got back to the shop, pulled the positive, held the brakes for a few seconds, then popped the relays back in, reconnected the battery, turned the key and held my breath...

And the bitch started!

No code, no hesitation, no nothing but 110db of loud-*** airplane-hearted goodness (remember that I'm inside the working bay of my shop).

Woo-HOOOO!

I pulled it outside and let that ****** idle for about 10 to 15 minutes... Other than blue-smoking a bit, nothing off about it.

After a bit of idling, I even went as far as rolling up the tach and it responded better than it did before (I'z a hooooge advocator of the vac reduction, people)!

I slapped a tag on it, and too it out on to the public streets...

Got to the long-ish straight-away, out from the shop and hit the 10psi cut-off in about 10". (seconds, not inches).

FACK!

Well, all-in-all, everything's gravy. The vac is sitting at mebbe 15 (normal, with vac-reduct?)? and the tach is currently at about 11-1300.

Damn car is up again!!!

Now all I need to do is get a boost-controller and mebbe some kind of PFC to manage everything.

Wonder where I can find one'a doze and how much they'll cost me? (hint-hint)

Case solved...

For now.

(Now I need sleep. Went to the pub for a celebratory bit and had a few pints)