wrong MIL bulb lights to flash out DTC's in 94 Suburban?

I jumpered A&B on the data link connector to get the "service engine
soon" (MIL) light to try to blink out the diagnostic trouble codes.
(The thing lights after driving for 10 minutes and then usually turns
off after 20 more minutes. I suspect an EGR issue.)

Anyway, with A&B jumpered, the "ABS Antilock" indicator does the
blinking of code 12 ("system working") over and over again, nothing
more. The service manual says the "service engine soon" bulb is
supposed to be doing the blinking. What gives?

hillpc wrote:
> I jumpered A&B on the data link connector to get the "service engine
> soon" (MIL) light to try to blink out the diagnostic trouble codes.
> (The thing lights after driving for 10 minutes and then usually turns
> off after 20 more minutes. I suspect an EGR issue.)
>
> Anyway, with A&B jumpered, the "ABS Antilock" indicator does the
> blinking of code 12 ("system working") over and over again, nothing
> more. The service manual says the "service engine soon" bulb is
> supposed to be doing the blinking. What gives?

94 Surburban with a 5.7?
Probably NOT OBD I, That was a changeover year on the Sub.
You will need a scanner to read the codes.



--
Steve W.

> You will need a scanner to read the codes.
>
> --
> Steve W.

The service manual claims one doesn't need a scanner.

In article >,
hillpc > wrote:
>
>> You will need a scanner to read the codes.
>>
>> --
>> Steve W.
>
>The service manual claims one doesn't need a scanner.

I think by '94, you need the scanner. Older models didn't require it.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

hillpc wrote:
>> You will need a scanner to read the codes.
>>
>> --
>> Steve W.
>
> The service manual claims one doesn't need a scanner.

The problem is that 94-95 were change over years for auto makers. SOME
model/engine combinations used a mixed OBD system. They had the old
style ALDL but different hardware and software in the system. No way to
read those codes without a scanner.

The 94 Suburban shows up in the books as both an OBD I and OBD II
depending on which engine it has.


--
Steve W.

hillpc wrote:
>> You will need a scanner to read the codes.
>> --
>> Steve W.
>
> The service manual claims one doesn't need a scanner.

It is possible that you will need a scanner. Especially if it was made in 1994.
http://www.troublecodes.net/GM/
"NOTE: Some 94 & 95 models that DO have the A & B terminals still require a scanner."

Thanks, guys. Now I'm curious about the ABS light blinking a 12
pattern when I jumper A&B. I'll probably disconnect a wheel sensor
and see if it blinks out something else now.