PCMHammer read issues with 8.1L Suburban

[Theeee0]

All good, I thank you for the help so far. I have not used any user defined keys, my bad I meant the "test" button on the interface selection window.

[Theeee0]

It's all good, I appreciate the help so far. I haven't used a user defined key, sorry I meant the "Test" button on thew interface settings window.

[V8fan]

That voltage is very low. I don't know what pre-flight checks the PCM does before it'll accept a kernel upload, but I'd try a better power supply with higher voltage. It could be the PCM is unhappy to even enter this mode at 11.7 volts, though I'd expect it to reject the request rather than just go silent and not stop talking like the logs show.

If that doesnt work, the other noteworthy thing is that it stops responding when the speed changes to 4x. It might be worth trying the operation at 1x speed. The setting is in the interface setup screen. Disable 4x.

Code: Select all

[06:40:46:709] Attempting switch to VPW 4x
[06:40:46:721] TX: 6C FE F0 A0
[06:40:46:739] RX: 6C F0 10 E0 AA
[06:40:46:740] Parsing 6C F0 10 E0 AA
[06:40:46:744] Module 0x10 (engine controller) has agreed to enter high-speed mode.

After that there is no more receives (RX) from the PCM.

same with sm2
I think its j2534 driver problem or wrong mode of j2543 driver

[09:21:59:854] Sending 'test device present' notification.
[09:21:59:858] TX: 8C FE F0 3F
[09:21:59:869] Attempting switch to VPW 4x
[09:21:59:876] TX: 6C FE F0 A0
[09:21:59:903] RX: 6C F0 10 E0 AA
[09:21:59:907] Parsing 6C F0 10 E0 AA
[09:21:59:911] Module 0x10 (engine controller) has agreed to enter high-speed mode.
[09:21:59:915] Sending 'test device present' notification.
[09:21:59:918] TX: 8C FE F0 3F
[09:22:02:027] ReadMsgs OBDError: ERR_BUFFER_EMPTY
[09:22:02:031] Sending 'test device present' notification.
[09:22:02:035] TX: 8C FE F0 3F
[09:22:02:045] TX: 6C FE F0 A1
[09:22:04:054] ReadMsgs OBDError: ERR_BUFFER_EMPTY
[09:22:04:058] J2534 setting VPW 4X
[09:22:04:074] Sending 'test device present' notification.
[09:22:04:078] TX: 8C FE F0 3F
[09:22:04:084] Sending 'test device present' notification.
[09:22:04:087] TX: 8C FE F0 3F

[antus]

Many tools probably don't support 4x or have had little testing for J2534 large packets for reflash. Most tools we don't talk about much here are designed with only logging in mind and not reflash. I would expect SM2 to work, but as always if you loose communications when switching to 4x, try 1x. If that works, stick with that. If you have problems the first time you see kernel upload (large outbound packet) or first data read packet (first large read packet) then its probably an interface problem handling the large packet size.

[V8fan]

Most tools we don't talk about much here are designed with only logging in mind and not reflash.

SM2 and 3 claimed as reflash tools

if you loose communications when switching to 4x, try 1x.

Damn -the only reason I bought it -4x speed cuz my obd SX works flawless but only 1x
Anyway it works at 1x (but I need 4x )
Successfully read P01

[antus]

Well at least it works at 1x. I guess it is a reflash tool but yeah....

[V8fan]

its probably an interface problem handling the large packet size.

Is there anything I can do with it ? I have zero knowledge how to open its driver but I can poke it with hot soldering iron till its death

[antus]

Well you show a working read at 1x speed. So the problem is not the packet size, the problem is that it does not support 4x. Also note that you only have 11.8v shown. You'll need above 12v to safely write it, ideally within 12.5 to 14v so get a better power supply or battery before you attempt a write.

I don't think you'll be able to add 4x without open source firmware, but if you wanted to build your own there was an open source interface called the obddiag allpro that you could build and which the firmware is open source and which I contributed 4x support already. But it's developer took it off the internet when pcmhammer came out and I assume he got overloaded with requests as it went from a hobby project to mainstream. For a good low cost interface your best of with obd xpro.

[V8fan]

Also note that you only have 11.8v shown. You'll need above 12v to safely write it, ideally within 12.5 to 14v so get a better power supply or battery before you attempt a write.

As I mentioned before - I use home PC as a power source so its 12V stable mostly
I read and write black box ,P01 P59 E38 E83 without any issue
Common ground between USB and power source very helpful for R/W without noise and interruptions
Maybe it (<12v) can be a problem if used almost empty battery in car where a lot of powerful loads that can produce power drops and spikes?

For a good low cost interface your best of with obd xpro.

I not forget yet
Just dont have an option to buy it without problems cuz my bank card not valid for ur bank and I need third party hands to give him his additional money to make it happen

there was an open source interface called the obddiag allpro

Will check thanks