Connecting VAG 1598/22 Test Box

Air Conditioning, Electrical Testing

Wiring and component testing using V.A.G 1598 A test box

Special tools and equipment
- V.A.G 1598 A test box and V.A.G 1598/11 adapter cable and V.A.G 1598/12
- VAS 5051 Vehicle diagnostic, Testing and Information System with VAS 5051/7 measuring leads, VAS 5051/8 DSO measuring cable and VAS 5051/9 Current pick-up clamp 50 A
- V.A.G 1527 B Voltage Tester
- V.A.G 1594 A connector test kit
- Temperature sensor with suitable tester

NOTE: The adapters from V.A.G 1598 A test box must not be connected to the A/C Control Head E87-during the On Board Diagnostic (OBD).

Connect V.A.G 1598 A test box to wiring harness connectors of A/C Control Head -E87-
- Switch ignition off.
- Remove A/C Control Head -E87-.







- Connect V.A.G 1598/11 adapter cable and V.A.G 1598/12 to disconnected harness connectors of A/C Control Head -E87-.

NOTE:
- Do not connect A/C control head -E87-.
- To carry out the measurement, connect the V.A.G 1598 A test box to relevant adapter lead.
- The socked assignment on V.A.G 1598/12 adapter corresponds exactly to the terminal assignment on the A/C Control Head -E87-.
- The socked assignment on V.A.G 1598/11 adapter does not corresponds exactly to the terminal assignment on the A/C Control Head -E87- terminal assignment.

Socket assignment for V.A.G 1598 A test box with adapter lead V.A.G 1598/11

NOTE:
- The terminal assignment for connectors A and B on the V.A.G 1598/11 adapter does not match the socket assignment on the V.A.G 1598 A test box.
- The terminal assignment for connector C on the V.A.G 1598/11 adapter matches exactly the socket assignment on the V.A.G 1598 A test box.
- The terminal assignment for connector D on the V.A.G 1598/12 adapter matches exactly the socket assignment on the V.A.G 1598 A test box.
- Because the connectors for the A/C Control Head -E87- are distributed over two adapter cables ((V.A.G 1598/11 and 12) there is no Ground (GND) connection for testing purposes when V.A.G 1598/11 adapter cable is connected. Therefore, for various steps of the electrical test it is necessary to use a suitable Ground connection point on the body of the car, or to use a second V.A.G 1598 test box. With the V.A.G 1598/12 adapter the Ground (GND) connection is through terminal 13).







Checking

Test requirement:
- All fuses OK:
- V.A.G 1598/11 adapter cable and V.A.G 1598/12 connected to disconnected harness connectors of A/C Control Head -E87-.







- Select operating mode "Test instrument" on VAS 5051 Vehicle Diagnostic, Testing and Information System







- Select during the variable test steps the required test instrument types, by clicking the relevant button on VAS 5051 display.

Electrical tests (to be performed on A/C Control Head -E87-) overview

NOTE: A variety of information is sent via the CAN-bus comfort system, no electrical testing applies for this information. Refer to Read measuring value block. Measuring Value Blocks (Function 08)

Test Component tested
step

1 - Voltage supply and Ground (GND) connection of A/C Control Head -E87-
2 - Fresh Air Intake Duct Temperature Sensor -G89-
- Sensors -G151-, -G152-, -G261-, -G262-, -G263-
3 - Wiring connection to Control module for fresh air blower -J126- and to Fresh Air Blower -V2-
4 - Positioning motors for climate control system and potentiometers -V70-, -G112-, -V71-/-G113-,
- V107-/-G135-, -V113-/-G143-, -V158-/-G220-, -V159-/-G221-
5 - Pressure signal from High Pressure Sensor -G65-
6 - Activation for A/C Compressor Regulator Valve -N280-
7 - Signal from Sunlight Photo Sensor -G107-

Test step 1 to 4

Test step 1:

Voltage supply and Ground (GND) connection of A/C Control Head -E87-

Test Step 1.1 - 1.3:

Test Step 1.4 - 1.6:

Test step 2:

Temperature sensor /sender

Test Step 2.1 - 2.4:

Test Step 2.5 - 2.6:

NOTE: The wiring connection to these sensors terminate on different connectors, for this reason use a second V.A.G 1598 A test box or connect the measuring unit direct to V.A.G 1598/12 using a suitable test lead from the V.A.G 1594 A

Temperature depending resistance values of sensor/sender:

Test step 3:

Voltage supply and wiring connection to Control module for fresh air blower -J126-and to Fresh Air Blower -V2-

Test step 3.1:

Voltage supply to Fresh Air Blower -V2-checking
- Switch ignition off.
- Remove glove compartment.







- Disconnect connector (A) from Control module for fresh air blower -J126- (B).
- Measure voltage between terminal -4- and terminal -3- on connector -A-

Specification: Battery voltage

NOTE:
- If voltage is below battery voltage, repair voltage and Ground (GND) connection according to wiring diagram.







- On vehicles with sunroof with solar cells, with the sunroof closed the generated voltage of the solar cells is present on terminal 6 of the connector.
- The Control module for fresh air blower -J126- is continuously monitored by the A/C control head -E87-, if a malfunction occurs, this will be stored in the DTC memory. The current status of Fresh Air Blower -V2- is displayed in the measuring value block, see Read Measuring Value Block, (display group 018). Measuring Value Blocks (Function 08)

Wiring connection to Control module for fresh air blower -J126-

Test Step 3.2 - 3.3:

Test Step 3.4 - 3.7:

Test step 4:

Air conditioner positioning motors with potentiometers

NOTE:
- The resistance value of potentiometer in the positioning motors (Specification: 3.6 to 5.7 kohm. Between terminal 1 and 3 can only be measured at the motors themselves (they are connected in parallel).
- The resistance value of the potentiometers in the positioning motors (between terminals 1 and 2 and between terminals 3 and 2) depends on the position of the positioning motor, and must always be measured with the positioning motor installed. The upper specified value is not obtained in test steps 4.1 and 4.2. (In order to reach the upper specified value, all harness connectors from other positioning motors must be disconnected during the measurement (switched in Parallel).
- If the A/C Control Head -E87- detects the malfunction "Potentiometer short circuit to Ground (GND)" or "Open/short circuit to B+", check all the potentiometers and the wiring.
- If DTC memory recognizes several positioning motors as faulty and the malfunction cannot be detected in test step 4, check potentiometers in all positioning motors and the wiring connection between the positioning motors for short circuit (e.g. with harness connectors disconnected between -V107- and -V70- and -E87- between socket 1, 2 and 3 in pertaining connector the tester must read infinite ohm

Test Step 4.1 - 4.2:

Test Step 4.3:

Test Step 4.4 - 4.8:

Test Step 4.9 - 4.10:

Test Step 4.11:

Test steps 5 to 9

Test step 5:

Pressure signal from High Pressure Sensor -G65-

Test Step 5.1 Part 1:

Test Step 5.1 Part 2:

Test Step 5.1 Part 3: