I have noticed an intermitant surge at idle during stops, this goes away when i place the trans (allison) in neutral. is this a trans problem or an engine control module problem.it has happened about 3-4 times in the last month.
2004 crew cab 4x4 sb build date 2/27/04 22k miles at present time

ButchKrouse

04 05 6.6 LLY Smoke , Fuel Knock , Surging and High Injector Balance Rates - kw white black idle surge rough noise accelerate P0300 P0301 P0302 P0303 P0304 P0305 P0306 P0307 P0308 miss misfire SES DTC #PIP3129B - (Oct 21, 2004)

04 05 6.6 LLY Smoke, Fuel Knock, Surging, and High Injector Balance Rates

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The following diagnosis might be helpful if the vehicle exhibits the symptom described in the PI.

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1557897#ss1-1557897">Condition/Concern:

Customer concern may be a low speed surge (8 to 10 mph or near 1000 RPM), acceleration fuel knock noise at 1700 to 1800 RPM, rough idle, white smoke at idle, or high positive injector balance rates.

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1557897#ss2-1557897">Recommendation/Instructions:

<LI type=1>High positive injector balance rates (over +4.0 in park or +6.0 in drive) may be causing white smoke at idle or while driving. <LI type=1>Document all injector cylinder balance rates at the beginning of the diagnosis. <LI type=1>There is an updated calibration to address the white smoke, high positive balance rates, idle surge, and a fuel knock noise at or near 1700 to 1800 RPM. <LI type=1>Install the updated calibration and evaluate the smoking, high injector balance rates, idle surge, and fuel knock noises.
If there is still a mechanical concern with an injector, and balance rates are still over the SI specification of +4.0 in park or +6.0 in drive, replace only the effected injector.
NOTE: Before any injector replacements, a large fuel sample should be taken from the fuel filter and checked for contaminants or poor quality.

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Please follow this diagnosis 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. If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1557897#ss3-1557897">Models:

(04 05 LLY 6.6 C2 C3 K2 K3 Chevrolet Silverado 2500HD,3500) and (04 05 LLY 6.6 C2 C3 K2 K3 GMC Sierra 2500 HD,3500 ) and (04 05 LLY 6.6 C4 C5 D4 D5 E4 E5 Chevrolet Kodiak 04 05 LLY 6.6 C4 C5 D4 D5 E4 E5 GMC Topkick)

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Reflash only moves the problems up a few hundred rpm. No cure at this time (I was told by GM) or that is the way a diesel runs (I have not had this on the previous 6 diesel trucks), as 2 dealers have told me. Thanx Geo 2004.5 Chev