File in Section:

Service Bulletin

Bulletin No.:
Date:

PIE0253
April, 2013

PRELIMINARY INFORMATION
Subject:

Engineering Information – Service Engine Soon Lamp Illuminated, Increased Engine
Noise, Perceived Higher RPM Shift Points (Caused By Excessive Cooling Fan Noise) or
Reduced A/C Performance At Low Vehicle Speeds

Models:

2011-2013 Chevrolet Express, Silverado Equipped with Duramax Diesel Engine (RPO
LML, LGH)
2011-2013 GMC Savana, Sierra Equipped with Duramax Diesel Engine (RPO LML, LGH)

Attention: Proceed with this PI 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 Service Bulletin 04-00-89-053E
for more details on the use of Engineering Information PIs.

Condition
Important: If the customer did not bring their vehicle in for this concern, DO NOT proceed with this EI.
Some customers may experience their service engine soon (SES) light coming on, increased engine noise or
perceived high RPM shift points (because of fan noise), or reduced A/C performance at low vehicle speeds. Upon
diagnosis, the technician may find DTCs P0483 Cooling Fan System Performance or P0526 Cooling Fan Speed
Sensor Circuit set.

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.

Instructions
This PI is intended to capture, from the customer, what the operating conditions were when the SES Light was first
noticed. In addition, specific diagnostic information needs to be recorded prior to replacing components.
Use the following steps to document the requested information:
1. Gather the following information from the customer:
• Approximately what was the outside temperature and climatic conditions?
• What speed were they traveling?
• What driving conditions, such as stop and go traffic, freeway, off road, operating in hilly terrain, and what
grades?
• What were the vehicle loading conditions such as empty, towing a trailer (size and load), any sort of vehicle
payload/equipment (size and load)?
• Were they using a snowplow or other added equipment?
• Was a winter grille cover on at the time?
• Any other relevant conditions noted?
2. Perform diagnostics per Service Information.
2.1. If DTCs P0483 or P0526 are set, determine the appropriate repair per Service Information, but do not
repair the vehicle.
2.2. Please note exactly what diagnostics and repair procedure are required per SI.
3. Before performing any repairs to the vehicle, call one of the engineers listed below with the collected
information.

Contact Information
Engineer Name

Phone Number

John Keeney

248-763-2780

Adam Freeman

248-836-8836

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

J7631*

Engineering Information – Service Engine Soon Lamp Illuminated
DTCs P0483, P0526

0.4 hr

*This is a unique labor operation for bulletin use only. It will not be published in the Labor Time Guide.