GMC Yukon 2000–2006

▸Known issuesThrottle body carbon build-up: idle surge, reduced engine power, throttle DTCs (high mileage)1

1. Manufacturer communication2006 GMC YUKON ・ 2018-01-16

   Engine Control System Update - Idle Surge and Power Mode Issues

   1. 1Fault

      • Loss of engine power, no acceleration
      • Reduced Engine Power
      • P0068
      • P0121
      • P1516
      • P2101
      • P2119
      • P2176
      • If enough carbon builds up, an idle surge, deceleration surge, tip-in hesitation, reduced engine power mode, and/or DTCs P0068, P0121, P1516, P2101, P2119 and/or P2176 may be experienced on high mileage vehicles.
      ↓→

   2. 2Finding the cause

      Possible causes

      • As carbon builds up in the throttle body of a high mileage vehicle, the ECM/PCM learns to compensate by increasing the throttle plate angle.

      Steps to confirm (in the document’s order)

      1. If SI diagnosis does not isolate the cause, inspect the throttle body bore and plate for obvious carbon build up.
      2. Depending on the vehicle, the idle learn reset/reset idle learn is normally found on the Tech 2 ECM menu for Module Set Up or Special Functions/TAC System.
      ↓→

   3. 3Correction

      Repair

      1. If carbon is present, follow the Throttle Body Cleaning Procedure in SI to clean the throttle body.
      2. After ensuring that the throttle body bore and plate are clean, perform an idle learn reset/reset idle learn with the Tech 2/GDS and re-evaluate the concern.

      Caution

      • If the throttle body is cleaned without performing an idle learn reset/reset idle learn with the Tech 2, the ECM/PCM may continue to compensate for the previous carbon build up, and the concern may return along with DTCs P0121, P0506 and/or P0507.
      • If the ECM/PCM of a high mileage vehicle is replaced and/or reprogrammed without performing the Throttle/Idle Learn outlined in SI, it may no longer compensate for existing carbon build up in the throttle body.
   Read the sentences of the record

   From the manufacturer’s document

   • Applies to：The model table lists the GMC Yukon, model years 2006 - 2018, all V8 engines.
   • Condition：If enough carbon builds up, an idle surge, deceleration surge, tip-in hesitation, reduced engine power mode, and/or DTCs P0068, P0121, P1516, P2101, P2119 and/or P2176 may be experienced on high mileage vehicles.
   • Cause：As carbon builds up in the throttle body of a high mileage vehicle, the ECM/PCM learns to compensate by increasing the throttle plate angle.
   • Confirm：If SI diagnosis does not isolate the cause, inspect the throttle body bore and plate for obvious carbon build up.
   • Repair：If carbon is present, follow the Throttle Body Cleaning Procedure in SI to clean the throttle body.
   • Repair：After ensuring that the throttle body bore and plate are clean, perform an idle learn reset/reset idle learn with the Tech 2/GDS and re-evaluate the concern.
   • Caution：If the throttle body is cleaned without performing an idle learn reset/reset idle learn with the Tech 2, the ECM/PCM may continue to compensate for the previous carbon build up, and the concern may return along with DTCs P0121, P0506 and/or P0507.
   • Caution：If the ECM/PCM of a high mileage vehicle is replaced and/or reprogrammed without performing the Throttle/Idle Learn outlined in SI, it may no longer compensate for existing carbon build up in the throttle body.
   • Confirm：Depending on the vehicle, the idle learn reset/reset idle learn is normally found on the Tech 2 ECM menu for Module Set Up or Special Functions/TAC System.

   Open the manufacturer’s document (PDF) ↗ The points above were read from this document.

   Remedy

   This PI was superseded to update model years and add information concerning idle surge, reduced engine power mode, and/or DTCs P0068, P0121, P1516, P2101, P2119, and/or P2176 that may be experienced on high mileage vehicles. Please discard PIP4578.