PIP5498M

Bulletin No.: PIP5498M
Published date: 08/21/2020
Preliminary Information
PIP5498M SES Lamp P050D P0300 Setting On A Cold Start And/Or
a Run Rough Warm with No codes
Models
Brand:
Model
Years:
Model:
VIN:
Engine:
from to
Transmissions:
Cadillac
CTS-V
2016 - 2020 All
All 6.2L LT4
All
Cadillac
Escalade
2015 - 2020 All
All 6.2L L86
All
Chevrolet Camaro
2016 - 2020 All
All 6.2L LT1 LT4
All
Chevrolet Corvette
2016 - 2019 All
All 6.2L LT1 LT4 LT5
All
Chevrolet Silverado LD
2014 - 2019 All
All
2019 - 2020 All
All 4.3L, 5.3L, 6.2L L82, L84, L87
All
Chevrolet Suburban
2015 - 2020 All
All 5.3L L83
All
Chevrolet Tahoe
2015 - 2020 All
All 5.3L L83
All
GMC
Sierra
2014 - 2020 All
All 4.3L, 5.3L, 6.2L L83, L86, LV1, LV3
All
GMC
Sierra 1500 (New Model)
2019 - 2020 All
All 4.3L, 5.3L, 6.2L L82, L84, L87,
All
GMC
Yukon Models
2015 - 2020 All
All 5.3L, 6.2L L83, L86
All
Chevrolet
Silverado 1500 (New
Model)
4.3L, 5.3L, 6.2L L83, L8B, L86, LV1,
All
LV3
Note: GM Technical Assistance continues to receive Dealer calls on a concern of DTC P050D and P0300 ,with the
engine disassembled with a no trouble found.
Involved Region or Country North America
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 P0300 and P050D,
NOTE: PLEASE BE SURE TO FIRST FOLLOW SI. DIAGNOSTICS for P0300 and P050D THEN, IF DTC P050D
FLOWCHART DOES NOT ISOLATE THE CONCERN, THEN THE FOLLOWING MAY BE HELPFUL.
Follow the ow chart for the P0300 to validate that there is not an ignition or mechanical concerns
with or without the P0300 set.
When completing the ow P050D chart, be sure you are checking the injector balance rates while the
engine is cold.
Be sure to record the injector balance rates and attach to the work order.
If an injector concern is found, replace only the a ected injector.
Note: This will need to be done before the engine is disassembled
Note: If the injectors are being replaced on L86, LT1, LT4 or LT5 there are three di erent ow rates injectors
o ered. Be sure to install the same ow rate injectors back into the engine by checking the part number on the
injector housing. Mixing the ow rates will cause drivability concerns, DTC setting and repeat injector
replacements.
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 mis re 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.
Mis res 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 warm 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 con rm 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 mis res. 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 History
Version
12
Modified
05/15/2017 Created
06/14/2017 - Updated Concern Information
08/08/2017 - Updated Correction Information
10/31/2017 - Updated Correction Information
12/01/2017 - Updated Correction Information
12/11/2017 - Updated Model Years
03/22/2018 - Added Parts Note
05/16/2018 - Added the LT5 engine
06/06/2018 - Update the Correction information
06/12/2018 - update to follow Si. for the P0300
05/07/2019 - Updated Model Years
04/03/2020 - Updated Admin Details.
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