Checking CO2-content of additional heater exhaust gas — AUDI

Notes:

The additional heater is switched on via the function "Basic setting, display group number 022" =>Page
01-51
The additional heater can be operated via the function "Basic setting" up to a coolant temperature of 115 °C. Starting from control interval is possible. The operating time is limited to a maximum of 8 minutes.
Observe the test requirements =>Page
82-27

Switch on exhaust analyser V.A.G 1788 and insert relevant exhaust probe hose into auxiliary heater exhaust pipe -A-.

Note:

Exhaust probe should not impede flow of exhaust gas from exhaust pipe during test.

Connect the vehicle diagnostic, testing and information system VAS 5051 to the vehicle's 16-pin diagnostic connector using diagnostic cable VAS 5051/1, with the ignition switched off => Page
01-14
Start the engine.
Use the "address word" 18 to select the -J162 additional heater electronics control unit
Set the air conditioner or heater to maximum heating output (e.g. rotary knob up to "Warm" stop and blower to stage 4).
Switch on the additional heater via the function "Basic setting, display group number 22" => Page
01-49

Display on VAS 5051:

The following display appears in area -2-:
Basic setting
Additional heating
Heating

Note:

If another or an additional display appears in the area -2-, eliminate the cause of the fault => Page
01-49

Wait until the additional heater has been switched from start to full load operation (approx. 3 min).

Note:

The current operating status of the additional heater can be seen in the measured value block "display group 001" => Read measured value block Page
01-67

After the additional heater has switched to full load operation, wait at least another 1 minute
Read off the measured value for the CO2 (carbon dioxide) content in the exhaust gas from the CO2-measuring instrument (starting approx. 5 minutes after switching on, the additional heater must be in full load operation).

Note:

Exhaust probe should not impede flow of exhaust gas from exhaust pipe during test.

Specified value:

Diesel engine
8 to 13 % CO2 by volume.

Notes:

If the measurement is outside the permitted range:
Check the intake area for the combustion air blower and the exhaust system of the additional heater for dirt and clean, if necessary.
Check the fuel delivery rate of the metering pump => Page
82-19

If CO2 level in exhaust gas and metering pump delivery rate are within the lower permitted range:
Replace the metering pump -V54 => Page
82-25

If CO2 level in exhaust gas is not OK, but fuel delivery rate is OK:

Check the air intake area (with intake silencer) and the exhaust system of the additional heater and repair, if necessary.

If no fault is found:
Check the combustion air blower -V6.
Set the CO2-content in the exhaust gas => Page
82-34
If the CO2-content in the exhaust gas cannot be set, replace the combustion air blower -V6 => Page
82-65

If the additional heater has starting difficulties although the fuel delivery rate and the CO2-content in the exhaust gas are OK:
Check the -Q8 glow plug with flame detector => Page
01-106
Remove any deposits from the burner element of the additional heater (only when running on vegetable oil methyl ester) => Page
82-42
Replace the burner element => Page
82-60
.