I've converted my '72 Blazer to TPI and all seems to be going well except for 1 minor problem....well maybe 2.

First, The SES light is dimly it at all times. I've gone over all the wiring and it seems to be correct. Any hints?

Second, I get a code 42 when hooked up to a scanner but not when I jumper the ALDL. Wierd. I've gone through the whole diagnostic thing for a code42 and came up with bad ECM. So, I picked up another off Ebay and it didn't fix things. I'm stumped. Are the 2 problems related?

It's a MAF setup and I had the chip burned by GMTuners.com.

Anybody got any ideas?

Thanks.

 

Perhaps the chip burner disabled some of the error codes. Those can usually be turned off and on in the programming.

What year/type ECM did you use for the TPI?

 

It's off an '87 T/A so it's a '165 ECM. He should have disabled the EGR but any idea why I would be getting a code 42 from a scan but not from the SES light?

Thanks,
M.

 

The '42' may have been disabled as well as the '32'. The conditions that set it would still exist and be diagnosed, but would not write a '1' to the output table so the SES would light. Programming can get a little strange in those areas.