Subject:

Engineering Information – Malfunction Indicator Lamp (MIL) On, DTCs P0171 Fuel Trim System
Lean Bank 1 and/or P0174 Fuel Trim System Lean Bank 2

Attention:

Proceed with this EI ONLY if the customer has commented about this concern AND the PIE
number is listed in the Global Warranty Management / Investigate History link (GWM/IVH). If the
customer has not commented about this condition or the EI does not show in GWM/IVH,
disregard the PI and proceed with diagnostics found in published service information. THIS IS
NOT A RECALL — refer to the latest version of Service Bulletin 04-00-89-053 for more details on
the use of Engineering Information bulletins.

Brand:

Model:

Model Year:

VIN:

from

to

Buick

Enclave

2014

2018

Chevrolet

Traverse

2014

2018

Chevrolet

Equinox

2014

2017

GMC

Acadia

2014

2018

GMC

Terrain

2014

2017

from

Engine:

Transmission:

LLT, LFY or LFX

All

to

Involved Region or Country

North America

Additional Options (RPO)

Equipped with 3.6L HFV6 Engine RPOs (LLT), (LFY) or (LFX)

Condition

Important: If the customer did not bring their vehicle in for this concern, DO NOT proceed with this
EI.
Some customers may comment on a malfunction indicator lamp (MIL) illuminated.
Upon investigation technician may find DTCs P0171 Fuel Trim System Lean Bank 1 and/or P0174
Fuel trim System Lean Bank 2 active or stored in history.

Cause

GM Engineering is attempting to determine the root cause of the above condition. Engineering has a
need to gather information on vehicles PRIOR to repair that may exhibit this condition. As a result,
this information will be used to "root cause" the customer's concern and develop/validate a field fix.

Correction

1

If you encounter a vehicle with the above concern, check for leak at the foul PCV tube to manifold connection as illustrated above.

•

If a leak is found, contact the engineer listed below.

•

If no leak is found, continue diagnosis referring to SI.

Contact Information
Engineer Name

Phone Number

Charlie Allen

(248) 878-1599

Please include the following information if leaving a message:
–

Technician name

–

Dealer name and phone number

–

Complete VIN and repair order (R.O) number

On the repair order, document the date and time the call was placed (even if the engineer was not reached).
If engineering is unable to return the call within one hour, proceed with diagnosis and repair based on information found in SI.

Warranty Information
If engineer was contacted or required information was provided, use:
Labor Operation

Description

Labor Time

4081898*

Engineering Information — Malfunction Indicator Lamp On DTCs
P0171 Fuel Trim System Lean Bank 1 and/or P0174 Fuel Trim System
Lean Bank 2

0.4 hr

*This is a unique Labor Operation for Bulletin use only. It will not be published in the Labor Time Guide.

2