Note On Operation Of Auxiliary/Additional Heater In Vehicles With Diesel Engine - Audi 2003 A8 Workshop Manual

♦ A second rating plate (duplicate) -A- is affixed to the bonnet in
the engine compartment (next to air conditioner label -B-). In
cases of doubt concerning auxiliary/additional heater model,
always observe rating plate attached to auxiliary/additional
heater.
♦ "Adaption" function can be used to switch additional heater
control unit -J364- to a different type of fuel (e.g. from petrol to
diesel and vice versa). As, however, the internal design of the
auxiliary/additional heater differs depending on type of fuel,
auxiliary/additional heater conversion work is also required if
it is to be fitted in a vehicle using the other type of fuel. Attention
is therefore to be paid to the rating plate affixed to the auxiliary/
additional heater.
♦ If the assignment of the auxiliary/supplementary heater (rating
plate) differs from the information given on the fault reader
display, check the assignment (reading measured value
block). The corresponding type of fuel must be displayed ⇒
"Guided fault-finding" function of vehicle diagnostic, testing
and information system VAS 5051.
♦ Heaters of type "Z / C- D" without circulation pump -V55- are
installed as additional heater on vehicles with 6-cyl. or 8-cyl.
diesel engine. As additional heater, the unit has no circulation
pump -V55- and no heater coolant shutoff valve -N279- . Front
operating and display unit ( Climatronic control unit -J255- )
activates the additional heater as soon as the specified acti‐
vation conditions are met. ⇒ Air Conditioner; Rep. Gr. 87
♦ If vehicles with 6-cyl. or 8-cyl. diesel engine are fitted with an
auxiliary heater (as optional extra), this will be a heater of type
"Z / C- D" with circulation pump -V55- and heater coolant shut‐
off valve -N279- . This auxiliary/additional heater is also oper‐
ated as additional heater.
♦ At present, the "Supplementary heating" function of the auxil‐
iary/supplementary heater is only available for vehicles with a
diesel engine. It is switched in automatically by the air condi‐
tioner front operating and display unit, Climatronic control unit
-J255- by way of the convenience data bus system, provided
that the front operating and display unit, Climatronic control
unit -J255- is in operation ("Off" mode not selected) and that
this function has not been deactivated via the MMI (Multi Me‐
dia Interface) ⇒ Owner's manual , ⇒ Operating instructions
for "Infotainment / MMI" and ⇒ Air conditioning; Rep. Gr. 87 .
♦ With the "Adaption" function it is possible to make an entry in
the front operating and display unit, Climatronic control unit -
J255- for deactivation of the supplementary heater on select‐
ing "Econ" mode on the front operating and display unit,
Climatronic control unit -J255- or for deactivation of the sup‐
Protected by copyright. Copying for private or commercial purposes, in part or in whole, is not
plementary heater in the MMI (Multi Media Interface) ⇒ Air
permitted unless authorised by AUDI AG. AUDI AG does not guarantee or accept any liability
conditioning; Rep. Gr. 87 and ⇒ "Guided fault-finding" func‐
tion of vehicle diagnostic, testing and information system
VAS 5051 (for the air conditioner).
♦ The "Adaption" function can be used to enter various changes
relating to auxiliary/supplementary heater actuation in the front
operating and display unit, Climatronic control unit -J255- . It
is also possible to alter certain settings for control action in
auxiliary heater mode ⇒ "Guided fault-finding" function of ve‐
hicle diagnostic, testing and information system VAS 5051 (for
the air conditioner).
1.3 Note on operation of auxiliary/additional
heater in vehicles with diesel engine
Problems with auxiliary/additional heater operation may be en‐
countered in cold weather (usually the only conditions under
which auxiliary/additional heater is switched on or actuated as
with respect to the correctness of information in this document. Copyright by AUDI AG.
Audi A8 2003 ➤
Auxiliary Heater - Edition 03.2008
1. Servicing auxiliary/additional heater
5