Ambient Air Temperature Sensor, Checking

2012 Audi A7SECTION Ambient Air Temperature Sensor, Checking

Special tools and workshop equipment required 

  • Multimeter.
  • Wiring diagram.

Test procedure 

-- Perform a preliminary check to verify the customers complaint. Refer to PRELIMINARY CHECK .

Start diagnosis 

-- Connect the scan tool.

-- Engine MUST be at room temperature.

-- Switch the ignition ON.

-- Using the scan tool, check the ambient air temperature:

Diagnostic text Specified value
Ambient Air Temperature (AAT) Approx. ambient air temperature

If the specified value was obtained:

-- Fault may be intermittent. Check for proper connection, damaged wiring or loose terminals.

-- Go to Final procedures.

NOTE:

The reading will default to 419° F if the circuit is open or shorted to ground.

If the specified value was Not obtained:

-- Connect a Multimeter to terminals 1 and 2 of the Ambient Air Temperature Sensor - G17- electrical harness connector.

-- Switch the ignition ON.

Specified value: About 5.0 V.

-- Switch the ignition OFF.

If the specified value was obtained:

Replace the Ambient Air Temperature Sensor - G17-. Refer to the appropriate Service Information.

-- Go to Final procedures.

If the specified value was Not obtained:

-- Remove the Vehicle electrical system control module -J519-. Refer to the appropriate Service Information.

Fig 1: Locating Vehicle Electrical System Control Module
GWWA97-11342Courtesy of AUDI OF AMERICA, LLC

-- Disconnect the Vehicle electrical system control module -J519- electrical harness connector T32a.

-- Using a Multimeter, check the Ambient Air Temperature Sensor -G17- electrical harness connector to the Vehicle electrical system control module -J519- electrical harness connector T32a for an open circuit or a short, refer to the appropriate wiring diagram.

Ambient Air Temperature Sensor -G17- electrical harness connector terminals: Vehicle electrical system control module -J519- electrical connector T32a terminals:
1 25
2 10

Specified value: 1.5 Ω max.

If the specified values were Not obtained:

-- Check the wiring connection for an open circuit.

-- Check the wiring connection for damage, corrosion, loose or broken terminals.

-- If necessary, repair the faulty wiring connection.

-- Go to Final procedures.

If the specified value was obtained:

-- Replace the Vehicle electrical system control module -J519-. Refer to the appropriate Service Information.

Final procedures 

After the repair work, the following work steps must be performed in the following sequence:

  1. Check the DTC memory. Refer to DIAGNOSTIC MODE 03 - READ DTC MEMORY .
  2. If necessary, erase the DTC memory. Refer to DIAGNOSTIC MODE 04 - ERASE DTC MEMORY .
  3. If the DTC memory was erased, generate readiness code. Refer to READINESS CODE .
RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.