Lack of Power with TAC Module Code of P1518 Reduced Power Mode -kw 4.8 5.3 6.0 DTC ETC L59 LM4 LM7 LQ4 LQ9 LR4 P1516 P2108 P0220 P0120 performance power throttle U0107

When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

Customers may have a concern of lack of power and engine light on. DTCs set will almost always contain a P1518 and may contain any of the following (P1516, P2108, P0220, P0120, U0107). An improperly torqued TAC module ground may be at fault. The Ground is listed as G104 on TAC module schematic which is incorrectly labeled on SI document ID 855376. The correct ground is G103. The locator for SI states that G103 is located on the left hand side which is incorrect. However, there have been field reports stating that G104 has also corrected this condition. G104 is a horizontal bolt in the rear of the left head and extremely difficult to reach. G104 should also be tightened at the same time.

There have also been field cases where ground G110 on the outer drivers side frame rail caused a P1518 code and an intermittent connection at splice 102 on the intake.

All published SI diagnostics should be followed in addition to following the recommendation listed.

Tighten ground G103 located behind the right cylinder head (passenger side) just below the head and mounted into the block. The ground uses a 13 mm bolt head mounted vertically to the engine block just above the bell housing.

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Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance. This diagnostic approach was developed for the vehicle with the VIN you entered and should not be automatically be used for other vehicles with similar symptoms.

(03 Chevrolet Silverado 2WD, 4WD) and (03 GMC Sierra 2WD, 4WD) and (03 Chevrolet Tahoe 2WD, 4WD) and (03 Chevrolet GMC Yukon 2WD, 4WD) and (03 Chevrolet Suburban 2WD, 4WD) and GMC Yukon XL 2WD, 4WD)

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