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Home >> Audi >> 1996 >> A4 Base, Automatic >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Controls - Tests W/Codes - 2.8L >> Circuit Tests >> DTC P0122/16506 - TP Sensor Circuit Low Input
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DTC P0122/16506 - TP Sensor Circuit Low Input

NOTE: DTC is set when signal voltage is less than .1 volt for more than 2 seconds with engine speed more than 6000 RPM.
  1. Inspect Throttle Position (TP) sensor connector for looseness and/or corrosion. Repair sensor connector as necessary. If sensor connector was not repaired, go to next step. If sensor connector was repaired, erase DTC memory and test drive vehicle.
  2. Turn ignition off. Disconnect TP sensor connector. Using a DVOM, check resistance of TP sensor. See THROTTLE POSITION (TP) SENSOR RESISTANCE table. If resistance readings are not to specification, replace TP sensor. If resistance readings are within specification, go to next step.
    THROTTLE POSITION (TP) SENSOR RESISTANCE

    Pin Nos. Ohms: At Idle Ohms: At WOT
    1 & 2 1500-2600 N/A
    2 & 3 750-1300 (1) 3600 Maximum
    (1) Resistance should gradually increase as throttle is opened.
  3. Turn ignition on. Using a DVOM, check voltage between TP sensor connector terminals No. 1 (B+) and 2 (ground). Check voltage between TP sensor connector terminals No. 1 (B+) and 3 (signal). Voltage should be 4.5-5.5 volts for both tests. If voltage is within specification, erase DTC memory and test drive vehicle. If voltage is not within specification, go to next step.
  4. Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Connect VAG 1598/19 test box to PCM wiring harness. Terminal assignments of test box are identical to PCM connectors "A", "B", "C", "D" and "E".
  5. Using DVOM, check resistance between TP sensor connector terminal No. 2 and test box socket D12. Maximum resistance is one ohm. If resistance is within specification, go to next step. If resistance is not within specification, repair open circuit. Erase DTC memory and test drive vehicle.
  6. Using DVOM, check resistance between TP sensor terminal No. 1 and test box socket A3. Maximum resistance is one ohm. If resistance is within specification, go to next step. If resistance is not within specification, repair open circuit. Erase DTC memory and test drive vehicle.
  7. Using DVOM, check resistance between TP sensor terminal No. 3 and test box socket A24. Maximum resistance is one ohm. If resistance is within specification, circuit is okay. Erase DTC memory and test drive vehicle. If resistance is not within specification, repair open circuit. Erase DTC memory and test drive vehicle. If an open circuit cannot be located, replace faulty PCM. Code new PCM and test drive vehicle. See PCM CODING  in this article.
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