Ignition System - MIL/ON DTC P0300-0306 Runs Rough
TECHNICALBulletin No.: 09-06-04-025A
Date: December 20, 2010
Subject: Malfunction Indicator Lamp (MIL) Illuminated, DTCs P0300-P0306 Set, Engine Runs Rough (Inspect for Water Intrusion in Spark Plug Recess Area, Replace Spark Plug and Ignition Coil, Seal Ignition Coil Bolt Hole Vents and Seal Hood Air Grille)
Models:
2008-2009 Chevrolet Colorado, TrailBlazer
2008-2009 GMC Canyon, Envoy
2008-2009 HUMMER H3, H3T
2008-2009 Saab 9-7X
All Equipped With Engine RPOs LLR, LLV or LL8
Please Refer to GWM/IMH
Supercede:
This bulletin is being revised to add an Important to the Hood Grille Modification section. Please discard Corporate Bulletin Number 09-06-04-025 (Section 06 - Engine/Propulsion System).
Condition
Some customers may comment that the malfunction indicator lamp (MIL) is illuminated.
Some customers may also comment that the engine runs rough.
The technician may find DTCs P0300, P0301, P0302, P0303, P0304, P0305, or P0306 set as current or in history, depending on which engine the vehicle is equipped with.
Upon further examination, the technician may observe evidence of water intrusion into the spark plug recess area.
Cause
This condition may be caused by an engine being exposed to a large quantity of water, which may result in some of the water seeping down past the vented threads of an ignition coil bolt, then flowing through the vent opening that is located in the bottom of the related ignition coil bolt hole, and collecting in the spark plug recess area.
Correction
Important
DO NOT reprogram or replace the engine control module (ECM) for this condition. If evidence of water intrusion in the spark plug recess area/s is not observed, then refer to the appropriate DTC procedures in SI.
1. Observe the Misfire Current Counters parameter with a scan tool, in order to determine the affected cylinder(s).
2. Remove the air cleaner resonator and outlet duct. Refer to Air Cleaner Resonator and Outlet Duct Replacement in SI.
3. Disconnect the engine wiring harness electrical connectors from the affected ignition coil(s). Refer to Ignition Coil Replacement in SI.
4. Remove the ignition coil bolt(s) and ignition coil(s) from the camshaft cover. Refer to Ignition Coil Replacement in SI.
Note
If water is observed in ANY of the spark plug recess areas, then it will be necessary to apply Loctite(R) 565 PST Thread Sealant* to ALL of the ignition coil bolt hole vents and bolt threads.
5. Inspect for water intrusion in the spark plug recess areas.
Warning
Wear safety glasses when using compressed air, as flying dirt particles may cause eye injury.
6. If any water is present, then remove the water from the spark plug recess areas with low pressure air.
7. Remove the affected spark plug(s) from the cylinder head. Refer to Spark Plug Replacement in SI.
8. Replace ONLY the affected spark plug(s) with new spark plug(s) as needed into the cylinder head. Refer to Spark Plug Replacement in SI.
9. Fill the bottom of the ignition coil bolt hole vent with Loctite(R) 565 PST Thread Sealant* as indicated in the illustration, and apply it to the ignition coil bolt threads also.
10. Replace ONLY the affected ignition coil(s) with new ignition coil(s) as needed. Refer to Ignition Coil Replacement in SI.
11. Connect the engine wiring harness electrical connectors to the ignition coil(s). Refer to Ignition Coil Replacement in SI.
12. Replace the air cleaner resonator and outlet duct. Refer to Air Cleaner Resonator and Outlet Duct Replacement in SI.
13. Clear the DTCs with a scan tool.
Hood Grille Modification for HUMMER H3 Vehicles Only
Important
Use the Investigate Vehicle History link in Global Connect, to determine if Recall #10088A: Product Safety - Hood Louver Separation has been performed on the vehicle. If Recall #10088A has been performed on the vehicle, DO NOT perform the following hood grille modification.
1. Remove the hood air grille. Refer to Hood Air Grille Replacement (H3) or Hood Air Grille Replacement (H3T) in SI.
2. Secure 3M(TM) Strip Calk(R), P/N 051135* around the outside perimeter of the integral retention clip (1) opening in the vehicle hood (all 4 sides of the rectangular slot).
3. Repeat this procedure for the remaining slots.
4. Install the hood air grille. Verify that it fits tightly against the hood. Refer to Hood Air Grille Replacement (H3) or Hood Air Grille Replacement (H3T) in SI.
5. Advise the customer to use care when washing the hood on the HUMMER vehicles. Extreme water pressure should not be directly applied to the edges of the hood air grille.
*We believe this source and their products to be reliable. There may be additional manufacturers of such products/materials. General Motors does not endorse, indicate any preference for, or assume any responsibility for the products or material from this firm or for any such items that may be available from other sources.
Parts Information
Warranty Information (excluding Saab Models)
For vehicles repaired under warranty, use:
Warranty Information (Saab Models)
For vehicles repaired under warranty, use the table.
Disclaimer