I have a 1995 Pontiac Sunfire with a 2.2-liter Vin code 4 Engine with an OBD1 PCM but an OBD2 interface connector.

I have a cable that has pins on one end (to connect to any interface connector) and a UBS connector, which connects with a laptop PC. An ALDL 8192 Baud DataStream is on pin 9 of the Data Link Connector.

A Windows XP Driver connects the USB interface as a Virtual Com port on Com 5.

The problem is that I don’t know which Vehicle file to use. So far, I’ve used LL0.xml and 1995 Pontiac Vin K.xml. Both have a Mode $01 frame of $F4, $57, $01, $00, $B4 for (presumably) getting DTCs.

When I click on chatter, I get a bunch of stuff that seems to be OK and a GREEN light on both MAX232 Interface and Chatter. When I try to send the Engine Data and DTC Macro by clicking on the Start ALDL button, I get the following message: (it’s difficult to print exactly what is there so this is an approximation without timelines).

Start Macro: Engine Data and DTC’s: DATADTCS
Error: reply frame checksum failure
Error: No echo received from Max232
Send: $F4, $57, $01, $00, $B4
Error: reply frame checksum failure
Error: No echo received from Max232
Error: reply frame checksum failure
Stop Macro: Engine Data and DTC’s: DATADTCS

I’m only guessing, but it seems that there is a timing problem of some kind since I can cause the MAX232 Interface to cease working if I set T6 to more than 25 ms.

Can anyone please help?