Testing Control Quality
Test Conditions:
Refer to paras. 1 to 4.
A. Control Quality Test:
paras. 5 to 11:
after 10-15 minutes driving, Nominal value 22 + 1 °C, with selector at 22 and function selections "Normal ventilation" and "Auto".
B. Heating Capacity Test:
paras. 12 to 14:
After 5 minutes with engine running at approx. 2000 rpm, Nominal value above 55 °C, with function selection "Def".
Commercially Available Tools:
Digital temperature measuring instrument with 4 test probes
- robbi temp 90020
- Air temperature measuring probe (cable 4.5 m long) 90023
Supplier e.g.:
Switzerland: Kent-Moore (Europe) AG
P.O. Box. CH-6340 Baar
Germany: Kalte-Fischer
Postfach 266, Augsburger Str. 289-291
D-7000 Stuttgart 60
Digital temperature measuring instrument with 4 test probes
- Therm 2263-2
- 4-point changeover switch 2235-4
- Air temperature measuring probe (cable 3 m long) W453-5
Supplier e.g.:
Germany: Ahlborn MeB- und Regelungstechnik,
Eichenfeldstr. 1-3.
D-8150 Holzkirchen
Note: Do not perform the test in the workshop, but on a cooled vehicle left in the open overnight. In-car temperature < 20 °C.
Test Conditions:
1. Outside temperature < 15 °C
2. Vehicle driven for approx. 10 mm before taking measurements. A longer drive is necessary in outside temperatures <0 °C.
3. Windows and sliding roof closed.
4. Do not warm the engine to its operating temperature beforehand.
5. Attach measuring probe to (right-hand) sun visor (arrow) and connect to measuring instrument. Then switch on measuring instrument.
6. On pushbutton switch (b) switch on function selection "Normal ventilation" and on blower switch (c) function selection "Max."
7. Switch off switch (S 24) (fresh air).
8. Close center outlet.
9. Set temperature selector (a) to 22.
10. Start up engine and drive off immediately (approx. 50-0 km/h).
11. After approx. 10-15 minutes, read off temperature on measuring instrument. Nominal value 22 ± 1 °C. If the temperature is not attained, test heating capacity or test system using contact box, voltmeter and ohmmeter.