2000 AUDI A4 diagram

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
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gnostic
(OBD
)
11/21/2002 htt
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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

01-36

VAG1551 scan tool
display Possible cause
Corrective action
01272 4123
Central Air Flap
Motor -V70-

Blocks or de-
energized /SP - Short circuit, open circuit in wiring or incorrect terminal
assignment (wires interchanged) of connectors between -
V70- and -E87-
- Central flap sticking
- -V70- malfunction- Diagnose and repair short circuit,
open
circuit or confirm terminal assignment
using wiring diagram
- Check for free operation of central
flap
- Test -V70- using function 03 (Output
DTM)
page 01
-42

01273 4124
Fresh air blower V2

Control
difference /SP - Short circuit or open circuit in wiring between V2, control
module for fresh air blower J126 and/or -E87-
- Open circuit in voltage supply or ground connection to -
J126-
- -J126- malfunction
- -V2- mechanical malfunction.- Diagnose and repair short circuit or
open circuit in wiring using wiring
diagram

- Diagnose and repair open circuit
using
wiring diagram
- -J126- electrical test page 01
-115
- Replace -V2-
01274 4131
Air flow flap motor
V71
- Short circuit, open circuit in wiring or incorrect terminal
assignment (wires interchanged) of connectors between
V71 and -E87-
- Air flow flap sticking- Diagnose and repair short circuit,
open
circuit or confirm terminal assignment
using wiring diagram
Pa
ge 48 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-37

VAG1551 Scan Tool display
Possible cause
Corrective action
01582
Coolant Temperature Signal
Short circuit or open circuit between
instrument cluster and A/C control head -
E87- - Locate short circuit or open circuit
according to wiring diagram and repair
Short circuit to
Ground /SP
Open/Short circuit
to B+ /SP
Incorrect
Signal /SP Instrument cluster malfunctioning- Check signal from instrument cluster.
Note:
The DTC "Coolant Temperature Signal" is only recognized by A/C control heads -E87- with one display.
Pa
ge 50 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-38
Diagnostic Trouble Code (DTC) table, changes specific to vehicles 1997

Notes:
The following DTCs are no longer recognized beginning m.y. 1997:

00529 Speed info missing (sensor -G111- deleted).
00799 A/C engine coolant temperature (ECT) sensor -G110- (sensor deleted).
00801 A/C refrigerant high pressure switch -F118- (switch deleted).
01270 A/C clutch -N25- (Sensor -G111- deleted).
The following DTCs are new for 1997, or are current DTCs with additional references to 1997 changes. DTCs and component
references include various malfuction causes in the display below the DTC, etc.
VAG1551 scan tool display
Possible cause
Corrective action
00604
Back Pressure Flap Motor
Position Sensor -G113- in Air
Flow Flap Motor -V71-1)

Short circuit to ground /SP
Open circuit/short circuit to
positive /SP - Short circuit, open circuit in wiring or incorrect
terminal assignment (wires interchanged) of
connectors between -G113- and -E87-
- Air flow flap not operating freely
- -G113- in -V71- inoperative- Diagnose and repair short circuit,
open circuit in wiring or confirm
terminal assignment using wiring
diagram

- Check for free operation of air flow
flap3)
- Replace -V71-
Pa
ge 51 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

01-39

VAG1551 scan tool
display Possible cause
Corrective action
00792 3224
A/C Pressure Switch
-F129-

Short circuit to
ground /SP - Open circuit in wiring/connections between -F129-
and -E87-
- Malfunction in operation of coolant fan -V7- (stage 1)


- Condenser or radiator dirty.
- Malfunction in operation of coolant fan -V7- (stage 2)
by A/C pressure switch -F129-
- -F129- malfunction
- Excess or low refrigerant system pressure- Diagnose and repair short or open circuit
in wiring using wiring diagram.
- Test fan operation -V7- (stage 1) using
function 03 (Output DTM)
page 01
-42

- -V7- electrical test
page 01
-115
.
- Clean condenser and radiator.
- Test -V7- (stage 2) via A/C pressure
switch -F129- page 87
-67
).
- Test -F129- page 87
-67
.
- Check refrigerant system pressures
page 87
-192
.
Notes:

A/C pressure switch -F129- contains 2 switching elements. Via terminals 1 & 2, the compressor is shut off due to low or
excess refrigerant system pressure (switch open). Via terminals 3 & 4, the second speed coolant fan is switched on
(switch closed).
When -F129- terminals 1 & 2 open, excess refrigerant pressure is initially recognized by A/C control head -E87- and a
DTC is stored. If the measured outside temperature is between 0 C & 50 C (32 F & 122 F) and -F129- terminals 1 &
2 remain open for longer than 30 seconds, -E87- switches over from excess pressure to low pressure (Low pressure
switch function) page 01
-86
, Read measuring value block (Display group 01 compressor shut-off conditions).
Pa
ge 53 of 91 A/C s
ystem, On Board Dia
gnostic
(OBD
)
11/21/2002 htt
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play?action=Goto&t
yp
e=re
pair&id=AUDI.B5.HA01.01.1

01-40

VAG1551 scan tool
display Possible cause
Corrective action
01206
Signal for time span
ignition off1)

implausible
signal /SP - Short or open circuit in wiring/connections
between instrument cluster and -E87-
- Instrument cluster malfunctioning.- Diagnose and repair short or open circuit in
wiring using wiring diagram.
- Check signal from instrument cluster using
function 08, Read measuring value block
page 01
-86
.
01274 4131
Air Flow Flap Motor -
V71- 2)

blocked or no
current /SP - Short or open circuit in wiring/connections
between -V71- and -E87-.
- Air flap or fresh/recirculated air flap
binding/sticking
- -V71- malfunctioning.- Diagnose and repair short or open circuit in
wiring using wiring diagram.
- Check air flap or fresh/recirculated air flap for
ease of movement.
- Check -V71- using function 03, Output
Diagnostic Test Mode (DTM) page 01
-42
.
1) If A/C control head -E87- is unable to determine the duration of time when ignition is off ("standing time"), DTC 01206
"signal for time span ignition off" is loaded into memory. The A/C control head will then default to a standing time greater than
4 hours. The actual measured values of the outside temperature sensor are then used as instantaneous outside and engine
temperature inputs for A/C system control. When the "heating" mode is selected under these conditions, the fresh air blower -
V2- has a delayed start (even when the actual standing time is less than 4 hours and the engine is warm) page 01
-86
,
Read measuring value block. The outside air temperature display -G106- may also indicate incorrect outside temperature
values.
2) -V71- operates the air flow flap as well as the fresh/recirculated air flap.
Pa
ge 55 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
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pair&id=AUDI.B5.HA01.01.1

01-41

VAG1551 scan tool
display Possible cause
Corrective action
01296
Sender for Outlet
Temperature, Center -
G191-

Short circuit to ground /SP

Open circuit/short circuit to
positive /SP - Short or open circuit in wiring/connections between -
G191- and -E87-
- Sensor -G191- malfunctioning- Diagnose and repair short or open
circuit in wiring using wiring
diagram
- -G191- electrical check page
01
-115

01297
Sender for Outlet
Temperature, Floor Outlet
-G192-

Short circuit to ground /SP

Open circuit/short circuit to
positive /SP - Short or open circuit in wiring/connections between -
G192- and
-E87-.
- -G192- malfunctioning- Diagnose and repair short or open
circuit in wiring using wiring
diagram.
- -G192- electrical check page
01
-115

65535
A/C control head -E87-

Malfunction
- Short or open circuit in wiring/connections between
terminal -15- or -31- to -E87-, contact resistance or
loose connection
- -E87- malfunctioning- Diagnose and repair short or open
circuit in wiring to -E87- using wiring
diagram

- Replace A/C control head -E87-
Pa
ge 56 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