Test Description

Number(s) below refer to step number(s) on Diagnostic Table.

1. 1. The On-Board Diagnostic (OBD II) System Check prompts technician to complete some basic checks and to store freeze frame and failure records data on scan tool if applicable. This creates an electronic copy of data taken when malfunction occurred. The information is then stored on scan tool for later reference.
2. 5. Visually/physically checking items which may cause a lean condition may determine cause of DTC being set and save diagnosis time.
3. 9. A vacuum leak can change Fuel Trim Index and set DTC P0171. This step checks intake manifold for vacuum leaks.
4. 11. Contaminants in fuel, such as alcohol or water, can create a lean condition setting DTC P0171. Checking for these contaminants could identify malfunction.
5. 17. If no faults have been found at this point and no additional DTCs were set, refer to "Diagnostic Aids" for additional checks and information.

Fig 1: DTC P0171: Bank 1 - System Too Lean (1 Of 3)

Courtesy of DAEWOO

Fig 2: DTC P0171: Bank 1 - System Too Lean (2 of 3)

Courtesy of DAEWOO

Fig 3: DTC P0171: Bank 1 - System Too Lean (3 Of 3)

Courtesy of DAEWOO