ECU EPROM bit rot?

[nthach]

68K/SuperH still lives on in cars and industrial applications. There is a push for ARM now - ST and Freescale/NXP are leading that. HMI - including UX and self-driving/ADAS needs more powerful processors. Nvidia, Intel and AMD are making a big play there - Tesla is using AMD Zen architecture APUs(CPU + GPU + AI accelerator), VW’s using Nvidia Tegra SoCs in Audis. 68K is 16-bit, Toyota states their PCMs are 32-bit.

The Intel 8088/8086 was very popular in cars as well. Even Hitachi, NEC and Oki made clones of it for the Japanese OES(Hitachi’s own Unisia JECS which was a JV with Bosch, Denso - also using Bosch licenses and Keihin for Honda).

 

[nthach]

Even capacitors from before that time will eventually leak (it's just that the bad ones leak much, much sooner). Shango066 on Youtube made a recent video about an ECU from a 1992 Ford F-series that had capacitor leakage, and it really damaged the board.

Yamae is the former Denso engineer here in this ClubLexus thread:
https://www.clublexus.com/forums/ls...exus-issues-solved-ecu-leaking-capacitor.html

 

[brianl703]

NEC had the V20 CPU which was a drop-in replacement for the 8088.

 

[LDM]

Supposing I wanted to back up the ROM in an 80s GM vehicle, what's the cheapest way to do it? Presumably I'd have to desolder it from the CALPAK.

You do not. All you need is a header to insert into the MEMCAL for the portion of the EPROM, then put it into a EPROM reader/burner, and then read the file from the chip.

https://www.moates.net/hdr1-memcal-header-p-52.html?cPath=64

I have this exact type as well as some others that are more flexible, this one will read most of the GM MEMCALs. There are a few special ones though so it will depend on your application. If you have one of the older 2732A style ECMs, you just need to pull it out of the socket. Those were used on the early 80s GM vehicles till about the mid to late 80s.

 

[Rmay635703]

I would think it's possible. All solid state read/write devices have finite life limit (similar to solid state computer drives) and the older they are the lower the read/write limits.

IBM had 30 year MTBF devices for a long time, doubtful any vehicle maker used them

 

[Jetronic]

I would think the use of PROMs(the ones with a clear window for UV to wipe the chip) was rare in cars - regular ROM was more likely. EEPROMs didn’t make their way into cars until the 1990s.

Dead capacitors would be more of a concern.

I had a car with a PROM (sticker over window to block UV). But when I had the car remapped they put an EEPROM instead.

 

[paulo57509]

GM old school - UV erasable EPROM and Mem-Cal

Adapter with EEPROM that allows the use of Mem-Cal portion of old EPROM.

 

[CorvairGeek]

Early GM removable PROMs, 1981, 1983 and 1984.

 

[nthach]

IBM had 30 year MTBF devices for a long time, doubtful any vehicle maker used them

I know Panasonic(Matsushita), Rubycon and Nichicon has “automotive” rated hi-temp electrolytics with a 105*C service temp and 2000-5000 hour service life. Samsung and SanDisk(now Western Digital) made “automotive-grade” NAND flash for use as eMMCs or discrete SD cards for the OES to integrate into their designs.

I think all the ICs aren’t made to any higher standard, but the discrete and passive devices need to be in an automotive design. The IPxx and vibration/EMF resistance is more important in automotive electronics.