You have an older STi with a coil pack?
I haven't found any code that looks like it's computing a checksum... it's all fairly primitive. I do think my ROM dump has some errors in it though so I need to try dumping it again more carefully.
I've found the ignition tables -- there are basically two, one defining base timing and one defining the maximum permissible advance -- but not fuel tables. It appears that our ECU just uses very simple math to compute pulse width based on airflow, plus some enrichments/enleanments and whatnot. Very old-school.
ECU codes galore
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Yes. V4 came with a coil pack. It also has the same ignitor as a legacy turbo (different location).
As for the ECU, I'd be surprised if it has no fuel tables. Did you just pop out the 27c256 and read it? I can see if I 've got time to wrestle out my ECU today so I can pop it open and have a look.
-Michael
As for the ECU, I'd be surprised if it has no fuel tables. Did you just pop out the 27c256 and read it? I can see if I 've got time to wrestle out my ECU today so I can pop it open and have a look.
-Michael
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vrg3
- Vikash
- Posts: 12517
- Joined: Sun Nov 03, 2002 2:13 am
- Location: USA, OH, Cleveland (sometimes visiting DC though)
- Contact:
Cool, I'm curious to hear whether to spark was just too weak.
I was surprised too. You can look for yourself.
I didn't desolder the ROM. I used the Select Monitor protocol to pull the information byte by painful byte. I did the download during a road trip since it takes several hours, so all the random RF and EM interference could have garbled a byte or two.
I was surprised too. You can look for yourself.
I didn't desolder the ROM. I used the Select Monitor protocol to pull the information byte by painful byte. I did the download during a road trip since it takes several hours, so all the random RF and EM interference could have garbled a byte or two.
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
I think the toughbook that I use for tuning has a parallel port.
I dug up the datasheets for the HD63140. Unfortunately they're stamped confidential. This means we had to sign a non-disclosure to get them. Can't really help you out there.
If you have any specific questions about the chip I can probably answer them. BTW it's a Universe Pulse Processor. Has a 4 channel 10 bit ADC, 1k of RAM and a watchdog timer.
-Michael
I dug up the datasheets for the HD63140. Unfortunately they're stamped confidential. This means we had to sign a non-disclosure to get them. Can't really help you out there.
If you have any specific questions about the chip I can probably answer them. BTW it's a Universe Pulse Processor. Has a 4 channel 10 bit ADC, 1k of RAM and a watchdog timer.
-Michael
Ok, reconnected the ECU.
Code 12
Abnormal signal emitted from starter switch
Code 21
Abnormal signal from water temperature sensor
Code 23
Abnormal voltage input entered from air flow sensor
Code 33
Abnormal voltage input entered from vehicle speed sensor
Code 49
Use of improper air flow sensor
Does anyone have a shop manual with the debugging steps for each of these codes? I'm hoping starting with the code 12 and working up will eventually lead to a bad connection or something responsible for the rest of the codes. Could be a bad ECU... Anyone in the Ottawa area have one they could lend me for 10 minutes?
-Michael
Code 12
Abnormal signal emitted from starter switch
Code 21
Abnormal signal from water temperature sensor
Code 23
Abnormal voltage input entered from air flow sensor
Code 33
Abnormal voltage input entered from vehicle speed sensor
Code 49
Use of improper air flow sensor
Does anyone have a shop manual with the debugging steps for each of these codes? I'm hoping starting with the code 12 and working up will eventually lead to a bad connection or something responsible for the rest of the codes. Could be a bad ECU... Anyone in the Ottawa area have one they could lend me for 10 minutes?
-Michael
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vrg3
- Vikash
- Posts: 12517
- Joined: Sun Nov 03, 2002 2:13 am
- Location: USA, OH, Cleveland (sometimes visiting DC though)
- Contact:
%$&# NDAs. Oh well, thanks.
Wait -- does the entity with which you entered into the non-disclosure agreement still exist? Cuz Hitachi doesn't make semiconductors anymore.
I did manage to learn that it was a UPP with 10-bit ADCs, some RAM, and a watchdog timer... What I'd really like to know is information about the pinouts and about programming its registers so I can follow traces and figure more out.
You can find factory service manual scans in a thread started by Josh (Legacy777) in the "Stuff you need to know" forum. He has the entire engine section of the FSM.
That's weird that all those codes would be there right away. It does seem like a power supply or ground issue, or a bad ECU.
Did you try it without the daughterboard?
Wait -- does the entity with which you entered into the non-disclosure agreement still exist? Cuz Hitachi doesn't make semiconductors anymore.
I did manage to learn that it was a UPP with 10-bit ADCs, some RAM, and a watchdog timer... What I'd really like to know is information about the pinouts and about programming its registers so I can follow traces and figure more out.
You can find factory service manual scans in a thread started by Josh (Legacy777) in the "Stuff you need to know" forum. He has the entire engine section of the FSM.
That's weird that all those codes would be there right away. It does seem like a power supply or ground issue, or a bad ECU.
Did you try it without the daughterboard?
"Just reading vrg3's convoluted, information-packed posts made me feel better all over again." -- subyluvr2212
I'd have to dig up the NDA. We did some automotive work for a company a few years back. It's complicated and they don't like to have some chip specs publicised. Not my problem. I have all the programming info and pinouts on said chip. If you needed to know what a specific pin was for I may be able to help but that may even be going too far. Looking at the docs I don't think they ever were available in electronic form.
Back on topic, this is the ECU with the original (not the daughterboard) chip installed. I socketted it as per my ECU chipping thread. I'll try to track down the conditions necessary for the starter code. Surprises me it worked with all the little addon autostarts and alarm modules under the dash. There never was a CEL so I have to assume all this just started at once.
-Michael
Back on topic, this is the ECU with the original (not the daughterboard) chip installed. I socketted it as per my ECU chipping thread. I'll try to track down the conditions necessary for the starter code. Surprises me it worked with all the little addon autostarts and alarm modules under the dash. There never was a CEL so I have to assume all this just started at once.
-Michael