How to get multiple diagnostic trouble codes?

Hi:

My engine light has been sporadically coming on in the last few days
(2000 Intrepid). I took it to a local place that told me it was an
emissions sensor and that is was fairly common for condensation to cause
this, and not to worry about it. Whatever.

But I wanted to verify it for myself the last time it came on. Using
the on-off-on-off-on trick, I get P 1684. A quick search reveals this
to be that the battery has been disconnected within the last 50 starts
(which is true).

My question: is this just the first code that comes up using the above
noted method, and that there is one or more trouble codes in memory that
I may or may not be able to retrieve because only one code can be
retrieved with this method? Is there a way to get multiple trouble
codes? Would a code reader be able to retrieve multiple codes?

Thanks.

 

Sorry, never mind. I wasn't patient enough: both codes are actually
reported, terminated by "done".

BTW: the code is "406 EGR position sensor voltage wrong." Any comments
on the mechanic's assessment that I shouldn't worry about it?

Thanks.

 

Sounds like you need a new EGR valve. P0406 is a result of an open circuit
in the feedback circuit for the EGR valve. According to your description
this is intermittent. There is no connector between the EGR valve and the
PCM in this circuit, so the problem has to be either an intermittent open
circuit in the EGR valve, intermittent open in the electrical circuit
between the EGR valve (light green with a pink tracer in pin 1 of the EGR
valve connector) and pin 34 of the PCM C1 connector (when you remove the
connector and look at the face of the connector, the black one. C2 is the
gray one) or an intermittent open in the same circuit but in the PCM. So
verify that the wire isn't chaffed and damaged. If the wire is OK, then
replace the EGR valve and I bet the problem will disappear. (make sure you
don't have any spread terminals that might make your intermittent
connection).

Bill