Curiosii for ever!: Car repair manuals for everyone.
Home >> Volkswagen >> 2000 >> New Beetle (1C1) L4-1.8L Turbo (APH) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Air Temperature Sensor ( Ambient / Intake ) >> Testing and Inspection >> Intake Air Temperature (IAT) Sensor, Checking >> With Manufacturer's Scan Tool

With Manufacturer's Scan Tool




Intake Air Temperature Sender, Checking


NOTE: Only gold-plated contacts must be used to repair the contacts in the intake air temperature sender.


Special tools, test equipment and auxiliary items
- Scan tool V.A.G 1551 or vehicle system tester V.A.G 1552 with cable V.A.G 1551/3B
- Test box V.A.G 1598/31
- Hand multimeter V.A.G 1526 or multimeter VAG 1715
- Adapter set V.A.G 1594
- Wiring diagram
- Pliers VAG 1921 for spring type clips
- Chilling spray (commercially available)

Test sequence
- Connect the scan tool V.A.G 1551 (V.A.G 1552). Then switch ignition on and select engine control module with the "Address word" 01. Connecting scan tool and selecting engine control module. Refer to "Scan Tool Testing/Scan Tool Connecting and Initial Checks/VAG 1551 Scan Tool", Testing and Inspection

Indicated on display


Rapid data transfer HELP
Select function XX


- Press keys 0 and 8 for the function "Read measuring value block" and confirm entry with Q key.

Indicated on display


Read measuring value block
Input display group number XXX


- Press keys 0, 0 and 4 for "Display group number 4" and confirm entry with Q key.

Indicated on display (1-4 = Display zones)


Read measuring value block 4 ->
1 2 3 4


- Read off intake air temperature value in display zone 4.


Display Group 4:






Evaluating display group 4, display zone 4 - Intake air temperature







Continuation of check when display = ambient temperature:







- Pull 2-pin connector (arrow) off intake air temperature sender (G42).







- Remove the intake air temperature sender (arrow).
- Re-connect 2-pin connector.
- Note intake air temperature value in display zone 4.







- Spray sender -arrow- with commercial chilling agent whilst observing the temperature value.
The temperature value must decrease.

If the specification is not obtained:
- Press -> key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Switch off ignition.

Continuation of check when display reads approx. -44.0 °C:







- Pull connector off intake air temperature sender (G42) (arrow).
- Bridge connector contacts using aux. cables from V.A.G 1594 and observe display.

If display jumps to approx. 143.0 °C:
- Press -> key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Switch off ignition.
- Replace intake air temperature sender (G42), item 28.
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory, checking and erasing DTC memory. Refer to "Displaying, Reading and Erasing Trouble Codes/With Manufacturers Scan Tool/DTC Memory, Checking And Erasing", Testing and Inspection
- Read-out the readiness code. If the DTC memory has been erased or the engine control module was disconnected from permanent positive, the readiness code must be generated again.
Refer to "Monitors Trips and/or Drive Cycle/Displaying Readiness Code", Testing and Inspection
Refer to "Monitors Trips and/or Drive Cycle/Generating Readiness Code", Testing and Inspection

If display remains at approx. -44.0 °C:
- Press -> key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Switch off ignition.
- Check wiring using wiring diagram.

Continuation of check when display reads approx. 143 °C:







- Pull connector -1- off intake air temperature sender (arrow).

If display jumps to approx. -44.0 °C:
- Press -> key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Switch off ignition.
- Replace intake air temperature sender (G42), item 28.
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory, checking and erasing DTC memory. Refer to "Displaying, Reading and Erasing Trouble Codes/With Manufacturers Scan Tool/DTC Memory, Checking And Erasing", Testing and Inspection
- Read-out the readiness code. If the DTC memory has been erased or the engine control module was disconnected from permanent positive, the readiness code must be generated again.
Refer to "Monitors Trips and/or Drive Cycle/Displaying Readiness Code", Testing and Inspection
Refer to "Monitors Trips and/or Drive Cycle/Generating Readiness Code", Testing and Inspection

If display remains at approx. 143 °C:
- Press -> key.
- Press keys 0 and 6 for the function "End output" and confirm entry with the Q key.
- Switch off ignition.
- Check wiring using wiring diagram.

Checking wiring
- Remove inner plenum chamber cover, left:







- Connect test box V.A.G 1598/31 to control module wiring harness. The engine control module is not connected by this action.







- Pull connector off intake air temperature sender (arrow).







- Check wiring between test box and 2- pin connector -1- for open circuit according to wiring diagram.
- Terminal 1 + Socket 85
- Terminal 2 + Socket 108
Wire resistance: max. 1.5 Ohms
- Additionally check both wires for short to battery positive.
Specification: Infinity Ohms

If no wiring malfunctions are detected:







- Perform resistance measurement at intake air temperature sender (G42) contacts 1 (signal) and 2 (Ground).







Scale A shows resistance values for temperature range 0 - 50 °C and scale B the values for temperature range 50 - 100 °C.

Examples:
- 30 °C is in range A and corresponds to a resistance of 1.5 - 2.0 k Ohms
- 80 °C is in range B and corresponds to a resistance of 275 - 375 Ohms

If the specification is not obtained:
- Replace intake air temperature sender (G42), item 28
- Check DTC memory, if necessary, repair any malfunctions and then erase DTC memory, checking and erasing DTC memory. Refer to "Displaying, Reading and Erasing Trouble Codes/With Manufacturers Scan Tool/DTC Memory, Checking And Erasing", Testing and Inspection
- Read-out the readiness code. If the DTC memory has been erased or the engine control module was disconnected from permanent positive, the readiness code must be generated again.
Refer to "Monitors Trips and/or Drive Cycle/Displaying Readiness Code", Testing and Inspection
Refer to "Monitors Trips and/or Drive Cycle/Generating Readiness Code", Testing and Inspection

If there is no malfunction in the wiring and the resistance measurement values are OK:
- Replace engine control module.
pro multis · Curiosii