Subject: | Reduced Engine Power in 4 Wheel Drive Low |
Models: | 2005 Chevrolet Silverado |
2005 GMC Sierra |
This information applies to only 2500/3500 vehicles equipped with a manual transmission and a 6.0L LQ4 engine. |
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
The customer concern may be SES/MIL light on and/or Reduced Engine Power Indicator on only when using four wheel drive low
Complete the current SI diagnostics for any symptoms or trouble codes found.
There has been an updated calibration released to address the reduced power mode or a DTC U0107 setting on 6.0L LQ4 manual transmission equipped vehicles.
This calibration addresses the reduced power mode or a DTC U0107 only when it occurs in four wheel drive low, and if engine load reaches 80% or higher.
If the U0107 code is not setting exactly as described above, diagnose using current SI procedures.
Please follow this diagnostic or repair 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.