01-34
 
 DTC 01270 continued 
VAG1551 scan 
tool display  Possible cause  
Corrective action  
01270 4121  
A/C Clutch N251) 
  
Speed difference 
too great /SP3) 
 
 
 
 
 
 
 
 
 
 
 
  
Continued on 
next page.  - Ribbed belt loose, slipping
 
 
 
- A/C control head -E87- not coded correctly
- Loose terminal or contact resistance in circuit between 
-N25- and A/C clutch relay -J44- or in wiring/connections 
between -G111-2)4) and -E87- 
- N25 slipping 
- Incorrect crankshaft vibration damper (diameter)
- Malfunction in refrigerant circuit (compressor not 
operating freely). - Check belt tension   Repair Manual, 
Engine Mechanical, Repair Group 13 
Compare speeds of engine and compressor 
using function 08 (Read measuring value 
block)  page 01
-63
  
- Code A/C control head -E87- according to 
compressor type installed4) "Zexel" or 
"Nippondenso"  page 01
-57
  
- Diagnose and repair circuit using wiring 
diagram and perform electrical tests 
 page 01
-115
 
- -G111-, -J44- electrical test   page 01
-
115
  
- Repair or replace -N25-   page 87
-85
- Check for proper vibration damper part 
number 
- Check compressor for free operation and 
replace if necessary   page 87
-38
 
1/2) Continued from   page 01
-33
  
3) If speed difference is 30 % to 60 %, A/C Clutch is switched on again by -E87- for not more than 9 times during a driving 
period (ignition off). If speed difference is greater than 60 %, A/C Clutch remains off until engine is started again. 
Pa
ge 44 of 91 A/C s
ystem, On Board Dia
gnostic 
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1 
01-35
 
 DTC 01270 continued 
VAG1551 scan tool 
display  Possible cause  
Corrective action  
01270 4121  
A/C Clutch N251) 
  
Mechanical 
malfunction /SP2)   - Belt and coupling pulley of -N25- are stuck together
- Short circuit to positive in wiring/connections between -
N25- and for A/C Clutch relay -J44- 
- -J44- malfunction
- Short circuit to ground in wiring/connections between -E87- 
and -J44- - Repair or replace -N25-   
page 87
-85
  
 
- Diagnose and repair short 
circuit using 
wiring diagram 
 
- Replace -J44-
- Diagnose and repair short 
circuit using 
wiring diagram. 
01271 4122  
Temperature Regulator 
Flap Motor V68 
  
Blocks or de-energized 
/SP  - Short circuit, open circuit or incorrect terminal assignment 
(wires interchanged) of connectors between -V68- and -E87-
- Temperature flap sticking
- -V68- malfunction- Diagnose and repair short 
circuit, open 
circuit or confirm terminal 
assignment using wiring 
diagram 
- Check for free operation of 
temperature flap 
- Test -V68- using function 03 
(Output DTM) 
 page 01
-42
 
Pa
ge 46 of 91 A/C s
ystem, On Board Dia
gnostic 
(OBD
)
11/21/2002 htt
p://127.0.0.1:8080/audi/servlet/Dis
play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1