K 3500 Truck 4WD V8-6.6L DSL Turbo VIN 1 (2001)
Mass Air Flow (MAF) Sensor: All Technical Service Bulletins
Diesel Engine - MIL ON/Poor Performance/DTC's Set
File In Section: 06 - Engine/Propulsion System
Bulletin No.: 01-06-04-050
Date: November, 2001
TECHNICAL
Subject:
Decreased Engine Performance/Power, Filter Minder Indicator On, Possible MIL Illuminated and DTC PO101/P0103 Set (Replace Air
Cleaner/Reprogram ECM)
Models:
2001 Chevrolet and GMC C/K Pickup Models with 6.6L Duramax(TM) Diesel Engine (VIN 1 - RPO LB7)
Condition
Some customers may comment on decreased engine performance/power on the above vehicles with the LB7 Duramax(TM) Diesel engine. The
Malfunction Indicator Lamp (MIL) may be illuminated with DTC P0101/P0103 set. The customer may also note that the "filter minder" on the air
cleaner assembly may indicate the filter element needs replacing at very low mileage. These symptoms are more likely to occur when pulling a trailer on
wet/slushy roads, but have been reported in heavy rain, at curb weight, during highway driving.
Cause
The LB7 diesel engine creates very high air flow under load. The primary source of inlet air to the engine is through the right front fender. The tires kick
up water spray on wet roads which is pulled in with the incoming air from the right fender opening located over the front bumper. This ingested water
may soak the airfilter element causing increased restriction. This restriction may activate the "filter minder". If the water continues past the filter, wetting
the mass air flow (MAF) sensor, the MIL may illuminate.
Important:
If the vehicle is being driven through snowy and/or slushy roads that have been salted, the MAF sensor may be contaminated with soluble road salt.
Correction
Install a revised air cleaner assembly, P/N 25345138, that has a lower incoming air velocity. Also, seal oft the right inner fender panel air inlet holes and
reprogram the ECM by following the procedure below.
1.
Open the hood and install fender covers.
2.
Remove the air cleaner assembly hose clamp from the ductwork.
3.
Disconnect the MAF sensor electrical connector.
4.
Remove the air cleaner assembly from the vehicle by pulling upward.
5.
Examine the air cleaner assembly for signs of salt intrusion (white, chalky powder). If signs of salt are present, and the vehicle has set a DTC
P0101 or P0103, install the air cleaner assembly by reversing the three steps above. Refer to the Engine Controls sub-section of the 2001 Service
Manual. The diagnostic table for DTC P0101 or DTC P0103 outlines the testing procedure for the MAF sensor. If the diagnostic test indicates a
contaminated MAF sensor (out of range), remove the air cleaner again and discard the complete assembly. Otherwise, remove the air cleaner and
continue with the next step.
Important:
It is critical that the surface you will bond the mastic material to be clean and grease tree. Poor preparation could lead to the mastic coming loose and
being sucked against the air filter element causing a poor power condition.
6.
Clean and degrease the right inner fender panel around the holes previously used for air intake.
Important:
Depending on the exact size of the mastic material received and the fasteners on the inner fender panel, you may need to trim the mastic material to
achieve a good fit.
7.
Apply the mastic material to the inner fender panel, completely covering and sealing the two holes that the original air cleaner snorkels protruded
into. Make sure that the mastic is firmly adhered to the inner fender panel.
