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Service bulletin 18NA026

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10137576
Published by NHTSA2018-05-21
Manufacturer's number18NA026
Manufacturer's date2018-04-17
NHTSA componentENGINE AND ENGINE COOLING; POWER TRAIN:AUTOMATIC TRANSMISSION:COOLING UNIT AND LINES

NHTSA's summary

This technical bulletin provides a procedure to install an oil cooler line fitting seal, including applying medium strength threadlocker (blue) to the retaining bolt to stop transmission fluid leaking from the transmission oil cooler line retaining bolt passage.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Engine, Transmission and driveline, Automatic transmission

Vehicles listed
BUICK ENCLAVE2018
BUICK ENVISION2018
CADILLAC ESCALADE2018
CADILLAC ESCALADE ESV2018
CHEVROLET CAMARO2017, 2018
CHEVROLET TAHOE2018
GMC YUKON2018
GMC YUKON XL2018

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
21-NA-2452024-04-05. Service bulletin. This service bulletin provides repair information to correct a customer concern of seeing a Shift to Park Message Displayed in DIC.
17-NA-0662023-07-25. Service bulletin. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
16-NA-1302023-03-08. Service bulletin. This service bulletin provides information for after installation of a replacement upper valve body, the transmission may have no Reverse and no 2nd gear.
PIP5621C2022-10-17. Service bulletin. This Preliminary information communicates to the dealer technician that TAC recommends the utilization of the GDS2 software to aid in diagnosing automatic transmission concerns. TAC is requesting the GDS2 session logs be sent in before the dealer contacts TAC.
22NA0422022-07-18. Service bulletin. Information on Camaro ZL1 10-Speed MGL Automatic Transmission Fluid Level Setting for the Track.
21NA1992022-02-14. Service bulletin. This informational bulletin advises the technician to replace the TBV if the transmission has any type of repair even if no problem was found, to replace the tbv.
990420002L2021-08-09. Service bulletin. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
PIE-0419A2021-04-17. Service bulletin. Engineering Information – Proceed Only if Diagnostics and Root Cause Activities Have Determined A Transmission Assembly Replacement
17-NA-3172021-04-15. Service bulletin. Transmission Shudder, Low Idle, Stalling after Auto Start , Reduced Engine Power Displayed on Driver Information Center (DIC), Malfunction Indicator Lamp (MIL) Illuminated - DTCs P034B, P0506, P0011, P0014, P0021 and/or P0024 Set Some customers may comment on the following conditions: • MIL is illuminated • Transmission shudder • Low idle • Stall after auto start • Reduced Engine Power displayed on DIC The technician may find one or more of the following DTCs set: • P034B • P0506 • P0011 • P0014 • P0021 • P0024 Cause This condition may be caused by the Crankshaft Position Sensor (CPS) circuit picking up EMI interference from unrelated control circuit in the same harness. Correction Replace the crank sensor portion of engine harness with a twisted pair jumper harness between the crank sensor and ECM connector.
16-NA-1752021-04-13. Service bulletin. SHAKE AND/OR SHUDDER DURING LIGHT THROTTLE ACCELERATION BETWEEN 40 AND 128 KM/H (25 AND 80 MPH) AT A STEADY STATE.