P1801 and P1805 code unknow
 

In my accent 2001 MIL go On and the DTC memory is filled whith this
code
P1128 P1805 P1801

I found in hmaservice.com web site doc about a first Powertrain code
where i look for P1801 and P1805 ????

The Italian hyundayi technician have replaced the ignition cord and
tell me that all rights and delete the DTC memory, but a few days
before the engine check lamp go on.

How resolve this problem ????



PS
Please, excuse me for my poor english

Re: P1801 and P1805 code unknow
 

P1128 indicates a lean condition under partial engine load. My experience
is that this is most often caused by the air flow sensor. I'm not
familiar with the Italian fuel management systems, so I'm not sure if it's
the same. You may want to look at TSB 01-36-022. I can't say whether any
of the values listed will be the same for Italy, but you should be able to
use the TSB as a guide to comparing your air flow sensor readings to an
identical vehicle which is operating properly.

P1801 and P1805 are immobilizer errors. Does your car have an anti-theft
device which reads a transponder in the key? If so, the problem is with
this system. I've never seen the system here in the U.S., but it is a
listed option in the parts catalog for certain parts.

Re: P1801 and P1805 code unknow
 

Thanks, your experience is precious.

In this car there is an immobilizer system and sometimes the car
don't start. I remove the key from the car and after reinsert it and
the car start normally.

possible scenery:
The car go normally while the immobilizer works good, but when the
immobilizer fault then P1128 codition is set ..............
Is potentially right for you???


PS
where you have found P1101 and P1105 error code ????





On Thu, 21 Apr 2005 18:21:05 -0400, "hyundaitech"
<notpublic@not.public.com> wrote:

>P1128 indicates a lean condition under partial engine load. My experience
>is that this is most often caused by the air flow sensor. I'm not
>familiar with the Italian fuel management systems, so I'm not sure if it's
>the same. You may want to look at TSB 01-36-022. I can't say whether any
>of the values listed will be the same for Italy, but you should be able to
>use the TSB as a guide to comparing your air flow sensor readings to an
>identical vehicle which is operating properly.
>
>P1801 and P1805 are immobilizer errors. Does your car have an anti-theft
>device which reads a transponder in the key? If so, the problem is with
>this system. I've never seen the system here in the U.S., but it is a
>listed option in the parts catalog for certain parts.

Re: P1801 and P1805 code unknow
 

The codes P1801, P1805, and your symptoms all suggest an immobilizer
problem. In GM products, the immobilizer problems are typically with the
lock cylinder sensor. I can't say how likely it is that will be the
problem in your car. I also have no idea why P1128 would set when the car
doesn't start. This code shouldn't set unless the car is running.

P1101 and P1105 relate to abnormal MAP sensor and air flow readings. I'd
investigate the MAP sensor and/or air flow sensor depending on which you
have on your car. I've replaced a couple MAP sensors, but not many. Air
flow sensors are more frequent issues.