Checking and adjusting CO2 content in auxiliary/additional heater exhaust gas — AUDI

Audi
Audi A8
2003
Heating, ventilation, air conditioning system
Auxiliary Heater
Edition
03.2008
Checking and adjusting CO
2
content in auxiliary/additional heater exhaust gas
Special tools and workshop equipment required
Exhaust emission test station
VAS 6300
Note
The CO
2
content in the exhaust gas can be set in the
“Adaption”
function
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
The
supplementary heater control unit
J364
can be used in the adaption function to alter actuation of the
combustion air blower
V6
. This changes the delivery rate and more or less combustion air is conveyed into the auxiliary/supplementary heater.
Vehicles with a diesel engine are fitted with a supplementary heater with no
circulation pump
V55
and no
heater coolant shut-off valve
N279
(as supplementary heater without
“Auxiliary heater”
optional extra). This version acts as additional heater and is only actuated by front operating and display unit (
Climatronic control unit
J255
) with engine running if heat generated by diesel engine is not sufficient to warm the passenger compartment.
As soon as front operating and display unit (
Climatronic control unit
J255
) is activated (by auxiliary/additional heater), it must be set to maximum heating output (temperature preselection
“Hi”
).
Additional heater (auxiliary heater without
circulation pump
V55
) must only be activated with engine running, as heat generated is not dissipated via coolant when engine is stopped.
On vehicles with a diesel engine and supplementary heater (without the
“Auxiliary heater”
optional extra), the engine is to be started before switching on the supplementary heater by way of the
“Basic setting”
function. As of a coolant temperature of greater than 40 °C the air conditioner is additionally to be set to
“Hi”
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051
.
In the
“Basic setting”
function, the auxiliary/supplementary heater can be operated up to a coolant temperature of 110 °C and starting from the control interval is possible. The operating time is then restricted to a maximum of 10 minutes
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051
.
Test requirements
At the start of testing, the coolant temperature should be less than 30° C (if the starting temperature is too high, the auxiliary/supplementary heater may switch to part load operation during testing or setting).
The ambient temperature is less than 25 ° C.
Sufficient fuel in tank (fuel gauge in dash panel insert not in red zone)
Battery
A
(vehicle battery) fully charged
Auxiliary/supplementary heater fully installed and connected to the vehicle electrical system
All auxiliary/supplementary heater fuses OK as per current flow diagram
Current flow diagrams, Electrical fault finding and Fitting locations
Encoding and adaption of the
supplementary heater control unit
J364
OK
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051
Auxiliary/additional heater off
Preparation
With the ignition switched off, connect up the
vehicle diagnostic, testing and information system
VAS 5051 A
, for example, with the
diagnostic wire
VAS 5051/5A
to the 16-pin diagnostic socket in the vehicle
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051
.
Switch on ignition (vehicles with auxiliary/supplementary heater).
Start engine (vehicles with diesel engine with additional heater only, without
“auxiliary heater”
optional extra).
Note
Auxiliary/additional heater self-diagnosis can only be started with ignition on (
data bus diagnostic interface
J533
is only active after switching on ignition). Once auxiliary/additional heater has switched to diagnostic mode, self-diagnosis can be continued with ignition switched off.
Vehicles with a diesel engine with supplementary heater only (no
“Auxiliary heater”
optional extra) are not fitted with a
circulation pump
V55
. On such vehicles the engine must be running to circulate the auxiliary/supplementary heater coolant and to prevent overheating.
Select the
“Guided fault-finding”
function
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
Read out the fault memories of all systems with self-diagnosis capability, paying particular attention to the following vehicle systems
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051
:
Dash panel insert
Air conditioner/heater electronics
Supplementary/auxiliary heater
Energy management control unit
J644
Data bus diagnostic interface
J533
Eliminate the cause of any faults displayed in the vehicle systems and erase the fault memory
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
Select the
supplementary heater control unit
J364
in the
“Guided fault-finding”
function
"Guided fault-finding" function of vehicle diagnostic, testing and information system VAS 5051.
Switch on the
exhaust emission test station
VAS 6300
and insert the appropriate exhaust probe hose
B
in the auxiliary/supplementary heater exhaust pipe
A
.