SES Light Due To DTCs P0101 And/Or P0106 - Inspect Air Filter And/Or Map Sensor - keywords 6.6L diesel engine freeze ice icing inlet intake LBZ LLY LMM mode power reduce reduced tube

This PI was superseded update the grill cover installation. Please discard PIP4307.

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

You may encounter a customer concern of reduced engine power, and a SES light on due to DTC P0101 and/or P0106.

The P0101 may be the result of snow ingestion into the air filter. The P0101 will only occur in areas with large amounts of blowing snow.

The P0106 may be the result of condensation that has frozen inside of the MAP sensor. The P0106 will only occur in areas with ambient temperatures at or below freezing for a long period of time.

Complete the SI diagnostics for any DTC or symptom found. If a P0101 is stored, inspect for snow ingestion into the air filter. If the vehicle is experiencing snow ingestion, install the grill cover (see notes at the bottom of this PI for description), and replace the air filter with part number 25839611 (see newest version of bulletin 07-06-04-033).

If a P0106 is stored, inspect the MAP sensor inlet. If there is condensation, water, or an oily substance in the MAP sensor inlet there has been an updated air intake tube released to address this concern. The updated air intake tube moves the MAP sensor to a new location.

1. If the dealer has verified a P0106 setting, and there are signs of MAP sensor freeze up, call the Product Quality Center (PQC phone number 866-654-7654) to order an updated air inlet tube. At this time, this updated air inlet tube is only available through the PQC. The PQC consultant will order a complete air inlet tube assembly as needed.
2. To install the updated intake tube the dealer will have to order new gaskets for the EGR valve, Intake Air Heater, and Intake Manifold Tube.
3. Refer to the "Intake Manifold Tube Replacement" procedure in SI and replace the air inlet tube with the updated air inlet tube received from PQC.
4. When completing the repair, the vehicles original MAP sensor will be left in its original position. Disconnect the MAP sensor electrical connector and connect it to the new MAP sensor in its updated location.
5. The Intake Air Heater/Map sensor wiring harness is retained to the intake tube with a metal bracket and a bolt. Remove the bolt and re-route the wiring harness so it will reach the new MAP sensor location. Retain the wiring harness as needed.
6. Reprogram the ECM with the latest calibrations if they are not present already.

Notes and description for grill cover installation.

If the vehicle is equipped with a two-piece grill cover, install only the upper portion of the cover. Do not install the lower portion that covers the front bumper.

Some 2008 GMT900 Trucks may have a one piece grill cover that covers both the bumper and the grill. Using this cover may restrict too much air flow if the vehicle is used for towing, plowing, or hauling heavy loads. Dealers are to order and replace the one piece cover with an upper grill cover.

Note: Customers should be instructed to only install the grill cover for cold weather driving. The following guidelines can be utilized. The customer should be advised to remove the cover at or above these temperatures:

Trailer Towing: Cover can be used up to 1.7C (35 F)

Non-Trailer Towing: Cover can be used up to 4.5C (40 F)

Important: If the information found in this PI does not repair the customer concern, submit a product report by following the latest version of bulletin 02-00-89-002.

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.