Checking actuation of auxiliary heater — AUDI

Measuring instruments and other items required

Portable multimeter V.A.G 1526
Adapter set V.A.G 1594
Diode test lamp V.A.G 1527

Test requirements

All fuses OK as per current flow diagram
Second battery OK and adequately charged
Coolant temperature less than 30°C

Checking

Switch off ignition and auxiliary heater.
Remove noise insulation.

=> General Body Repairs; Repair Group 50; Removing and installing noise insulation
General Body Repairs
Removing and installing noise insulation

Remove air duct to alternator (8-cyl. engine only).
Unplug both 3-pin connectors -A- and -B-.

Test step 1 (power supply for auxiliary heater)

Note:

Block diagram of auxiliary heater and pin assignment =>Page
82-177

Select measuring range: / Voltage measurement (20 V DC) / ▪ Measurement location: 3-pin connector -A- (black)on vehicle end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
1.1 · A1 / and / 4 · Power supply to auxiliary heater · ▪ Ignition off / ▪ Auxiliary heater off · - approx. battery voltage · - Use current flow diagram to locate and eliminate open circuit in wiring or contact resistance in power supply or in earth connection

Select measuring range: / Voltage measurement (20 V DC) / ▪ Measurement location: 3-pin connector -A- (black)on vehicle end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
1.2 · A1 / and / 4 · Connection between batteries -A and -A1 · ▪ Auxiliary heater off / ▪ Engine running · - approx. alternator voltage · - Use current flow diagram to locate and eliminate open circuit in wiring or contact resistance in connection between -A and / -A1 / Use current flow diagram to check actuation and operation of battery cut-out relay -J7

Test step 2 (actuation of auxiliary heater by pre-selection clock -E111)

Note:

Block diagram of auxiliary heater and pin assignment =>Page
82-177

Select measuring range: / Voltage measurement (20 V DC) / ▪ Measurement location: 3-pin connector -A- (black)on vehicle end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
2.1 · -E111 and / 4 · Pre-selection clock -E111 cut-in signal · ▪ Ignition off / ▪ Auxiliary heater off · - Less than 2V · - Use current flow diagram to locate and eliminate short to positive
2.2 · -E111 and / 4 · Pre-selection clock -E111 cut-in signal · ▪ Ignition off / ▪ Auxiliary heater on · - Greater than 7V · - Use current flow diagram to locate and eliminate short to earth, open circuit in wiring or contact resistance / Check pre-selection clock power supply=>Page 82-70

Select measuring range: / Voltage measurement (20 V DC) / ▪ Measurement location: 3-pin connector -A- (black)on vehicle end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
2.3 · -E111 and / 4 · Cut-in function of pre-selection clock / -E111 · ▪ Ignition off / ▪ Auxiliary heater off / Set cut-in time (1, 2 or 3) to approx. / 5 minutes before actual time and activate · - At activated cut-in time, voltage changes from less than 2V to greater than 7V · - Check pre-selection clock power supply=>Page 82-70 / Replace pre-selection clock

Test step 3 (actuation of metering pump -V54)

Notes:

Block diagram of auxiliary heater and pin assignment =>Page
82-177
Test step 3.1 must be completed within 80 s.

Diode test lamp / ▪ Measurement location: 3-pin connector -B- (white)on auxiliary heater end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
3.1 · -V54 (connector / -B-) and earth · Actuation of metering pump -V54 · ▪ Ignition off / ▪ 3-pin connector -A- plugged in / ▪ Switch -E16 not pressed / Switch on auxiliary heater at pre-selection clock · - Diode test lamp starts to flash approx. 32 s after switching on auxiliary heater · - Check auxiliary heater connectors for corrosion / Check electrical components of auxiliary heater / =>Page 82-206
- Plug in 3-pin connector -B- · - Metering pump -V54 is actuated (pulsed) · - Check actuation of metering pump =>Page 82-205

Test step 4 (actuation of operating and display unit for air conditioner/Climatronic -E87/fresh-air blower -V2)

Note:

Block diagram of auxiliary heater and pin assignment =>Page
82-177

Select measuring range: / Current measurement (2 A DC) / ▪ Measurement location: 3-pin connectors -A- (black) and -B- (white) on vehicle end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
4.1 · -A1 (connector / -A-) and / -J8 (connector / -B-) · Auxiliary heater relay -J8 · ▪ Ignition off / ▪ Auxiliary heater off · - Operating and display unit/fresh-air blower starts up / / Current input greater than 100 and less than 300mA · - Use current flow diagram to locate and eliminate short to earth, open circuit in wiring or contact resistance / Perform air conditioner self-diagnosis =>Air Conditioner Workshop Manual / Use current flow diagram to check relay -J8 and corresponding wiring

Test step 5 (heater/heat output switch -E16)

Note:

Block diagram of auxiliary heater and pin assignment =>Page
82-177

Diode test lamp / ▪ Measurement location: 3-pin connectors -A- (black) and -B- (white) on vehicle end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
5.1 · -A1 (connector / -A-) and / -E16 (connector / -B-) · Operation of switch -E16 · ▪ Auxiliary heater off / ▪ Switch -E16 not pressed · - Diode test lamp does not light · - Use current flow diagram to locate and eliminate short to earth / Replace switch -E16
5.2 · -A1 (connector / -A-) and / -E16 (connector / -B-) · Operation of switch -E16 · ▪ Auxiliary heater off / ▪ Switch -E16 pressed · - Diode test lamp lights · - Use current flow diagram to locate and eliminate open circuit in wiring or contact resistance / Replace switch -E16

Select measuring range: / Current measurement (200 mA DC) / ▪ Measurement location: 3-pin connector -B- (white) on auxiliary heater end
Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
5.3 · -E16 (connector / -B-) and earth · Auxiliary heater (output for detection of position of switch -E16) · ▪ Ignition off / ▪ 3-pin connector -A- plugged in / ▪ Auxiliary heater off / Switch on auxiliary heater at pre-selection clock / Switch off auxiliary heater at pre-selection clock / Plug in 3-pin connector -B- · - Less than 1 mA / / / / / / Greater than 1 and less than / 20 mA / Less than 1 mA · - Check electrical components of auxiliary heater / =>Page 82-206 / Replace auxiliary heater

Continued on next page

Test step · Contact · Testing of · ▪ Test conditions / - Additional work · Specification · Remedies if specification not attained
Continued from Page 82-203 · ▪ Switch -E16 pressed / Switch on auxiliary heater at pre-selection clock · - Operating and display unit/fresh-air blower starts up / Auxiliary heater does not start up · - Check electrical components of auxiliary heater / =>Page 82-206
- Actuate switch / -E16 (switch no longer pressed) / · - Auxiliary heater starts up / Operating and display unit/fresh-air blower initially switched off 1and then on again2 · - Check electrical components of auxiliary heater / =>Page 82-206

1) Only if coolant temperature in auxiliary heater less than 30°C

2) As soon as coolant temperature in auxiliary heater exceeds 30°C