2016 - 2017 Corvette: Service Bulletin: #PIP5498B: SES Lamp P050D P0300 Setting On A Cold Start And/Or a Run Rough Warm with No codes


#PIP5498B: SES Lamp P050D P0300 Setting On A Cold Start And/Or a Run Rough Warm with No codes - (Aug 8, 2017)

Subject SES Lamp P050D P0300 Setting On A Cold Start And/Or a Run Rough Warm with No codes

Brand:

Model:

Model Year:

VIN:

Engine:

Transmission:

from

to

from

to

Cadillac

CTS-V

2016 - 2017

All

All

6.2L LT4

All

Cadillac

Escalade

2015-2017

All

All

6.2L L86

All

Chevrolet

Camaro

2016-2017

All

All

6.2L LT1 LT4

All

Chevrolet

Corvette

2016 - 2017

All

All

6.2L LT1 LT4

All

Chevrolet

Silverado 1500

2014-2017

All

All

4.3L, 5.3L, 6.2L L83, L86, LV1, LV3

All

Chevrolet

Suburban

2015-2017

All

All

5.3L L83

All

Chevrolet

Tahoe

2015-2017

All

All

5.3L L83

All

GMC

Sierra 1500

2014-2017

All

All

4.3L, 5.3L, 6.2L L83, L86, LV1, LV3

All

GMC

Yukon Models

2015-2017

All

All

5.3L, 6.2L L83, L86

All

 

Involved Region or Country

North America

Additional RPO/s:

N/A

Condition

A vehicle may have a concern of DTC P050D setting along with a P0300 after a cold start up.

White smoke and/or coolant odor may come from exhaust for an extended period of time at cold start as well.

It may also Run rough when warm, slight knock, no codes setting. 

Cause

Coolant getting into the cylinders.

Correction

Technical assistance is currently receiving calls after the engine has been disassembled with no trouble found before completing  SI diagnostics for DTC P050D,

Please be sure to first follow SI diagnostics then, if DTC P050D flow chart does not isolate the concern, the following may be helpful

Code P050D Description

During a cold start, the engine control module (ECM) commands dual-pulse mode during Open Loop operation to improve cold start emissions. In dual-pulse mode, the fuel injectors are energized twice during each injection event. As with misfire diagnosis, in dual-pulse mode the ECM monitors the crankshaft position sensor and the camshaft position sensor to calculate crankshaft rotation speed.

In normal operation, optimum fuel delivery during dual-pulse mode produces a steady crankshaft rotation speed. If the variations of crankshaft rotation speed exceed a calibrated value, the code P050D will be set.

Misfires on start up only, with high rates always on one cylinder, can be suspect for coolant entry at the liner to deck face casting or the casting line in the intake port of the cylinder head.

To inspect for this concern, add coolant dye to the system, run engine through warm up, pressurize the cooling system after warming the engine to operating temperature (let the engine cool overnight) and inspect the suspect cylinder with a borescope for coolant dye evidence.

At times it may be necessary to remove the head for inspection.

If the head casting line is the concern the intake port will be wet with a coolant oil mix.

This could be the cause of a running rough warn concern with or without codes. 

The location of where the coolant is running down in the port will also look washed down. 


If this is found the cylinder head will need to be replaced. 

For coolant entry at the liner to deck face casting of the cylinder bore. 


It is hard to see the actual source (pin hole) but it usually streams down the liner so that you can see it with a borescope.(Sometimes) The top of the piston will be steam cleaned. 

Do not confuse residual fuel on the piston crown / surface as coolant. Some fuel residue may be present and can be mistaken as coolant (reason for the cooling system Dye to be added). Use black light to confirm the liquid is coolant. If this concern is present, do not replace the cylinder head because that will not repair this concern. Call PQC per the latest version of 16-NA-338, if required, reference this PI and replace the engine.

Small surface pock marks or pitting appearance on the deck surface is normal and engines should not be replaced for such appearance as they do not connect to coolant passages and cause a leak path that generate engine misfires. During engine warranty analysis studies, engines are being replaced for small pitting in the deck face as described above, when the subject cylinder / piston is saturated with fuel and not coolant

Engines replaced for light / shallow pitting conditions will be returned to the dealership as non-defective.

 

Version

3

Modified

6/14/2017 Updated Concern Information

8/8/2017 Updated Correction Information



Article ID: 1378
Created On: Wed, Aug 16, 2017 at 10:07 AM
Last Updated On: Wed, Aug 16, 2017 at 10:07 AM

Online URL: http://www.corvetteactioncenter.com/tech/knowledgebase/article/2016-2017-corvette-service-bulletin-pip5498b-ses-lamp-p050d-p0300-setting-on-a-cold-start-and-or-a-run-rough-warm-with-no-codes-1378.html