Need advice on LT1 PCM

[johnny_b]

I had a pcm I was trying to flash, at first it would connect but When I would try to flash it, it kept doing mode 13 timeout. Research told me that it was likely bricked. So I had the pcm socketed and put bootable images on the flash memory via an EEPROM. Now when I try to connect to eehack to flash all I get it’s “no echo!” Messages. Anyone know what my issue is?

[NomakeWan]

Which bootable image did you use? That would be my first suspicion, that the image was bad.

[kur4o]

The chips need some spacer underneath to make proper contact. Rule of thumb is they must be flush with upper edge of the socket. I suspect there is no good contact between chip and socket.

[johnny_b]

I’ve used these sockets a handful of times. Never had any issues before and never used shims. But I will try that. I grabbed the images of here and used them before successfully perhaps someone can’t point me to some?

[steveo]

the sockets are super bitchy. you can't solder them flush without snipping their bases out, then you either need to glue the bases back in or put a shim under them

as far as the image goes, one thing you have to keep in mind is that the images that we flash through the aldl port (which are either the eside and tside bins glued together or split apart) are drastically different from what you'd program using an eeprom programmer. the reason is that the address lines to the eeprom are scrambled.

you need to get ahold of the 'scrambled' version of the bin to program then later flash your custom bin through the aldl port

i do want to make a tool to convert between the two formats but never got around to deciphering it...

[steveo]

go in this thread: http://www.gearhead-efi.com/Fuel-Injection/showthread.php?1160-64K-bootable-image-for-95-LT1-PCM

find the bins posted by 96lt4c4 a few posts down

that's what i used to flash my socketed ECM when repeatedly bricking the damn thing during initial development of eehack....

[steveo]

hmm i just read your post again....

'no echo' has NOTHING to do with the ecm.

the echo comes from your serial interface due to the RX and TX lines being tied together

you might have a problem with that interface

even with the aldl cable unplugged from the car you shouldn't get 'no echo'

[johnny_b]

The files posted in that thread by 06lt4c4 are the exact ones I used.

I suspected it might be the cable. I use a moates aldl to usb with a homemade bench top harness that plugs into pcm. However when I plug this exact setup into another pcm it connects right away without issue. So I don’t think it’s the cable or homemade harness

[johnny_b]

Copy and paste from the debug:

Loading Definition DEVICE=0xF4 MSG=0x0
Loading Definition DEVICE=0xF4 MSG=0x1
Loading Definition DEVICE=0xF4 MSG=0x2
Loading Definition DEVICE=0xF4 MSG=0x3
Loading Definition DEVICE=0xF4 MSG=0x4
Loading Definition DEVICE=0xF4 MSG=0x5
Loading Definition DEVICE=0xF4 MSG=0x6
Loading Definition DEVICE=0xE4 MSG=0x0
Loaded 1014 elements into 8 definitions.
VERSION re-checking, network went online!
VERSION offline status, skipping versioning
Using monotonic reference clock.
EEHack Version 4.70
Current OS : Windows 10
Built with THROTTLE_MS=2
Opened serial port COM5 Description USB Serial Port MFR FTDI
START SILENCE ROUTINE
SERIAL: WAITED_TOO_LONG in serial_read_packet
SERIAL: No echo! (Serial interface problem..?)
SERIAL: WAITED_TOO_LONG in serial_read_packet
SERIAL: No echo! (Serial interface problem..?)
START SILENCE ROUTINE
SERIAL: WAITED_TOO_LONG in serial_read_packet
SERIAL: No echo! (Serial interface problem..?)
SERIAL: WAITED_TOO_LONG in serial_read_packet
SERIAL: No echo! (Serial interface problem..?)
START SILENCE ROUTINE