The owner of a 2008-09 TrailBlazer, Colorado, Canyon, Envoy, H3, H3T, or Saab 9-7x with inline 4/5/6 cylinder engine (RPO codes LLV, LLR, LL8) may experience a SES light and an engine misfire with DTCs P0300-P0306 stored in the ECM.
This condition may be the result of water in a spark plug well. If the top of the engine is exposed to a lot of water, it can drain down the vented threads of an ignition coil bolt, flow through the vent in the bottom of the related ignition coil bolt hole, and collect in the related spark plug well.
If SI diagnosis does not isolate the cause of this condition, remove the related ignition coil(s) and inspect the spark plug well for standing water.
If there is no sign of water, this information does not apply.
If water is present, extract the water and replace the related spark plug and ignition coil with new components.
IMPORTANT: Before installing the new ignition coil, fill the bottom of the ignition coil bolt hole with Loctite 565 PST Thread Sealant and apply it to the ignition coil bolt threads as well. (Fig. 13)
(Fig. 13)
For Hummer H3 models, also perform the following steps after the repairs above are complete:
1. Remove the hood air grille by following Hood Air Grille Replacement in SI.
2. Follow Steps 2a-2e to install foam gasket tape and reduce the chance of water dripping directly on the No. 1 ignition coil when the hood is power washed.
2a. Remove the flat retaining blade from the retaining clip. (Fig. 14)
(Fig. 14)
2b. Cut a piece of two-sided foam gasket tape the same size as the flat retaining blade.
2c. Cut a lengthwise slit in the center of the foam gasket tape.
2d. Install the foam gasket tape over and around the retaining clip, leaving the tip of the clip exposed through the slit.
2e. Install the flat retaining blade on the retaining clip. The foam tape will be between the flat retaining blade and hood air grille.
3. Install the hood air grille following Hood Air Grille Replacement in SI.
4. Inspect all the hood air grille retaining clips under the hood to ensure that they are all engaged, and make sure the hood air grille fits tight against the hood.
5. Advise customers to use care when washing the hood of their vehicle. They should not apply extreme water pressure directly on the edge of the hood air grille when washing their vehicle. (Fig. 15)
(Fig. 15)
- Thanks to Jamie Parkhurst
This condition may be the result of water in a spark plug well. If the top of the engine is exposed to a lot of water, it can drain down the vented threads of an ignition coil bolt, flow through the vent in the bottom of the related ignition coil bolt hole, and collect in the related spark plug well.
If SI diagnosis does not isolate the cause of this condition, remove the related ignition coil(s) and inspect the spark plug well for standing water.
If there is no sign of water, this information does not apply.
If water is present, extract the water and replace the related spark plug and ignition coil with new components.
IMPORTANT: Before installing the new ignition coil, fill the bottom of the ignition coil bolt hole with Loctite 565 PST Thread Sealant and apply it to the ignition coil bolt threads as well. (Fig. 13)
(Fig. 13)
For Hummer H3 models, also perform the following steps after the repairs above are complete:
1. Remove the hood air grille by following Hood Air Grille Replacement in SI.
2. Follow Steps 2a-2e to install foam gasket tape and reduce the chance of water dripping directly on the No. 1 ignition coil when the hood is power washed.
2a. Remove the flat retaining blade from the retaining clip. (Fig. 14)
(Fig. 14)
2b. Cut a piece of two-sided foam gasket tape the same size as the flat retaining blade.
2c. Cut a lengthwise slit in the center of the foam gasket tape.
2d. Install the foam gasket tape over and around the retaining clip, leaving the tip of the clip exposed through the slit.
2e. Install the flat retaining blade on the retaining clip. The foam tape will be between the flat retaining blade and hood air grille.
3. Install the hood air grille following Hood Air Grille Replacement in SI.
4. Inspect all the hood air grille retaining clips under the hood to ensure that they are all engaged, and make sure the hood air grille fits tight against the hood.
5. Advise customers to use care when washing the hood of their vehicle. They should not apply extreme water pressure directly on the edge of the hood air grille when washing their vehicle. (Fig. 15)
(Fig. 15)
- Thanks to Jamie Parkhurst
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