Lexus ES300 current drain ECM security module replacement

[redfxrs]

car has had recurring problem with battery dead after a few days of
inactivity. battery & charging system test fine but lexus dealer
states the trouble can be traced to "one of the back doors" and to fix
it they suggest replacing the ECM for the alarm/security system at a
cost of $498. i asked several questions:

1) if one of the back doors had a problem can a switch or sensor be
replaced. answer: no, the ecm must be replaced. part #8793033123
costs 318.80 and 2 hrs labor to install ecm and then re diagnose.
then service writer tells me "this may not cure the problem if
something shows when we re diagnose". so could be 500 plus much more,
they will not say or commit to a figure.

2) I asked about just disconnecting the ecm (they insist the security
has it's own) and locking the car with the key. when asked where the
ecm was located they told me "maybe in the trunk".

I cannot see the value to spending 500 on the car (maybe lots more)
but would like to stop the battery drain. i need to get a service
manual but in the meantime, does anyone know where the security ecm is
located and if it can be unplugged? also, if it is unplugged do i
lose keyless entry and trunk opener? any comments or recommendations
appreciated. i hate the lexus dealer...love the car. thanks
G

[redfxrs]

Post by redfxrs
car has had recurring problem with battery dead after a few days of
inactivity. battery & charging system test fine but lexus dealer
states the trouble can be traced to "one of the back doors" and to fix
it they suggest replacing the ECM for the alarm/security system at a
1) if one of the back doors had a problem can a switch or sensor be
replaced. answer: no, the ecm must be replaced. part #8793033123
costs 318.80 and 2 hrs labor to install ecm and then re diagnose.
then service writer tells me "this may not cure the problem if
something shows when we re diagnose". so could be 500 plus much more,
they will not say or commit to a figure.
2) I asked about just disconnecting the ecm (they insist the security
has it's own) and locking the car with the key. when asked where the
ecm was located they told me "maybe in the trunk".
I cannot see the value to spending 500 on the car (maybe lots more)
but would like to stop the battery drain. i need to get a service
manual but in the meantime, does anyone know where the security ecm is
located and if it can be unplugged? also, if it is unplugged do i
lose keyless entry and trunk opener? any comments or recommendations
appreciated. i hate the lexus dealer...love the car. thanks
G

FORGOT TO MENTION CAR IS 2001 ES300

[Ray O]

Post by redfxrs
car has had recurring problem with battery dead after a few days of
inactivity. battery & charging system test fine but lexus dealer
states the trouble can be traced to "one of the back doors" and to fix
it they suggest replacing the ECM for the alarm/security system at a
1) if one of the back doors had a problem can a switch or sensor be
replaced. answer: no, the ecm must be replaced. part #8793033123
costs 318.80 and 2 hrs labor to install ecm and then re diagnose.
then service writer tells me "this may not cure the problem if
something shows when we re diagnose". so could be 500 plus much more,
they will not say or commit to a figure.
2) I asked about just disconnecting the ecm (they insist the security
has it's own) and locking the car with the key. when asked where the
ecm was located they told me "maybe in the trunk".
I cannot see the value to spending 500 on the car (maybe lots more)
but would like to stop the battery drain. i need to get a service
manual but in the meantime, does anyone know where the security ecm is
located and if it can be unplugged? also, if it is unplugged do i
lose keyless entry and trunk opener? any comments or recommendations
appreciated. i hate the lexus dealer...love the car. thanks
G

I think the security module is either in the trunk or under one of the front
seats. If the security module is unplugged, then I'm pretty sure that you
lose the keyfob functions. Try disconnecting the fuse for the security
module and see if the drain goes away.

[PaulT]

Please let us know if the fix suggested by 'Ray O' is successful! thnx

Post by Ray O

Post by redfxrs
car has had recurring problem with battery dead after a few days of
inactivity. battery & charging system test fine but lexus dealer
states the trouble can be traced to "one of the back doors" and to fix
it they suggest replacing the ECM for the alarm/security system at a
1) if one of the back doors had a problem can a switch or sensor be
replaced. answer: no, the ecm must be replaced. part #8793033123
costs 318.80 and 2 hrs labor to install ecm and then re diagnose.
then service writer tells me "this may not cure the problem if
something shows when we re diagnose". so could be 500 plus much more,
they will not say or commit to a figure.
2) I asked about just disconnecting the ecm (they insist the security
has it's own) and locking the car with the key. when asked where the
ecm was located they told me "maybe in the trunk".
I cannot see the value to spending 500 on the car (maybe lots more)
but would like to stop the battery drain. i need to get a service
manual but in the meantime, does anyone know where the security ecm is
located and if it can be unplugged? also, if it is unplugged do i
lose keyless entry and trunk opener? any comments or recommendations
appreciated. i hate the lexus dealer...love the car. thanks
G

I think the security module is either in the trunk or under one of the
front seats. If the security module is unplugged, then I'm pretty sure
that you lose the keyfob functions. Try disconnecting the fuse for the
security module and see if the drain goes away.
--
Ray O
(correct punctuation to reply)