Operation CHARM: Car repair manuals for everyone.
Home >> Audi >> 2006 >> A8L Quattro Sedan (4E8) W12-6.0L (BSB) >> Repair and Diagnosis >> Powertrain Management >> Computers and Control Systems >> Testing and Inspection >> Component Tests and General Diagnostics >> Component Tests (SAE Code Tests) >> Intake Air Temperature Sensor, Checking

Intake Air Temperature Sensor, Checking






Diagnostic Procedures



Intake Air Temperature Sensor, Checking

• Use only gold-plated terminals when servicing terminals in harness connector of Mass Air Flow (MAF) sensor or Intake Air Temperature (IAT) sensor.

Special tools, testers and auxiliary items required

• Hand multimeter (V.A.G 1526) or Multimeter (V.A.G 1715)

• Test adapter kit (V.A.G 1594)

• Wiring diagram

• Chilling spray (commercially available)

Test conditions

• The fuses must be OK:

• For vehicles with automatic transmission, selector lever must be in " P".

• Parking brake must be engaged.

• The Ground (GND) connections between engine and body must be OK.

Function Test

- Connect diagnostic tester.

- Switch ignition on.

- Under address word 33, select "Diagnostic mode 1: Check measured values".

- Select measured value "PID 15: Intake air temperature".

- Check specified value of intake air temperature:





If specification is not obtained:

- Perform test according to the following table:





* If a temperature is indicated that is below the sensor's ambient temperature, first check sensor wires for contact resistance. Note that while the vehicle is standing still the sensor might warm up due to radiant heat.

If specification is obtained:

- Remove corresponding intake manifold between Mass Air Flow sensor and throttle valve control module.

- Remember intake air temperature value.

- Spray corresponding sensor - arrow - with commercially available chilling spray and watch temperature value. Temperature value must decrease.





- End diagnosis and switch ignition off.

If intake air temperature does not drop:

- Replace corresponding Mass Air Flow sensor with Intake Air Temperature sensor.

• Intake Air Temperature sensors are components of Mass Air Flow sensor and cannot be replaced individually.

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

°Continuation of Test If Indication is Approx. -40 C:

- Disconnect corresponding 5-pin connector from Mass Air Flow (MAF) sensor with Intake Air Temperature (IAT) sensor to be tested.

• 5-pin connector - arrow - from Mass Air Flow (MAF) sensor (G70) with cylinder bank 1 Intake Air Temperature (IAT) Sensor (G42).





• Cylinder bank 1 with cylinders 1 through 6 is located at right in direction of travel.

• Mass Air Flow (MAF) sensor (G70) with cylinder bank 1 Intake Air Temperature (IAT) Sensor (G42) is located left in direction of travel.

• 5-pin connector - 1 - from Mass Air Flow (MAF) sensor 2 (G246) with cylinder bank 2 Intake Air Temperature (IAT) Sensor 2 (G299).





• Cylinder bank 2 with cylinders 7 through 12 is located at left in direction of travel.

• Mass Air Flow (MAF) sensor 2 (G246) with cylinder bank 2 Intake Air Temperature (IAT) Sensor 2 (G299) is located at right in direction of travel.

- Bridge terminals 1 + 3 of connector using respective adapter cables while observing the indication on display.





If indication jumps to approx 140°C:

- End diagnosis and switch ignition off.

- Replace corresponding Mass Air Flow (sensor with Intake Air Temperature sensor.

• Intake Air Temperature (sensors are components of Mass Air Flow sensor and cannot be replaced individually.

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If indication remains at approx -40 °C:

- End diagnosis and switch ignition off.

- Check wires to control module according to wiring diagram.

°Continuation of Test If Indication is Approx. 140 C:

- Disconnect corresponding 5-pin connector from Mass Air Flow (MAF) sensor with Intake Air Temperature (IAT) sensor to be tested.

• 5-pin connector - arrow - from M ass Air Flow (MAF) sensor (G70) with cylinder bank 1 Intake Air Temperature (IAT) Sensor (G42).





• Cylinder bank 1 with cylinders 1 through 6 is located at right in direction of travel.

• Mass Air Flow (MAF) sensor (G70) with cylinder bank 1 Intake Air Temperature (IAT) Sensor (G42) is located left in direction of travel.

• 5-pin connector - 1l - from Mass Air Flow (MAF) sensor 2 (G246) with cylinder bank 2 Intake Air Temperature (IAT) Sensor 2 (G299).





• Cylinder bank 2 with cylinders 7 through 12 is located at left in direction of travel.

• Mass Air Flow (MAF) sensor 2 (G246) with cylinder bank 2 Intake Air Temperature (IAT) Sensor 2 (G299) is located at right in direction of travel.

If indication jumps to approx -40 °C:

- End diagnosis and switch ignition off.

- Replace corresponding Mass Air Flow sensor with Intake Air Temperature sensor.

• Intake Air Temperature sensors are components of Mass Air Flow sensor and cannot be replaced individually.

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If indication remains at approx 140 °C:

- End diagnosis and switch ignition off.

- Check wires to control module according to wiring diagram.

Check Wires to Control Module

Cylinder bank 1

- Connect test box to Engine Control Module (ECM) (J623) wiring harness on connecting test box for wiring test, refer to Repair Manual,

Cylinder bank 2

- Connect test box to Engine Control Module (ECM) 2 (J624) wiring harness on connecting test box for wiring test, refer to Repair Manual,

Cylinder bank 1 and 2

- Check wires between test box and 5-pin connector to Engine Control Module (ECM) for open circuit according to wiring diagram. Terminal 1+Socket 26, Terminal 3+Socket 27, wire resistance: max. 1.5 ohms





- Check wires for short circuit to each other, to vehicle Ground (GND) and to B+. Specification: infinite ohms

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If no malfunction is detected in the wiring:

- Measure resistance at Intake Air Temperature (IAT) sensor terminals 1 (signal) and 3 (Ground (GND)).





Range A displays resistance values for the temperature range of 0 to 50 °C, range B displays resistance values for the temperature range of 50 to 100 °C.





Example:

• 30°C is in range A and corresponds to a resistance of 1.5 to 2.0 kohms

• 80°C is in range B and corresponds to a resistance of 275 to 375ohms

If specification is not obtained:

- Replace corresponding Mass Air Flow sensor with Intake Air Temperature sensor.

• Intake Air Temperature sensors are components of Mass Air Flow sensor and cannot be replaced individually.

- Erase DTC memory of Engine Control Module => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Modes 01 - 09, Diagnostic mode 4: Reset/erase diagnostic data.

- Generate readiness code => [ Readiness Code, Generating ] Monitors, Trips, Drive Cycles and Readiness Codes.

If no malfunction is detected in the wiring, replace the engine control module.

pro multis · About Operation CHARM