WenmarOpen by Wenmar Pro

Service bulletin 18199

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 id10147331
Published by NHTSA2018-11-13
Manufacturer's number18199
Manufacturer's date2018-09-18
NHTSA componentPOWER TRAIN:AUTOMATIC TRANSMISSION

NHTSA's summary

18199 - Service Update - Software that controls the electric motor for the auxiliary transmission fluid pump has a fault in the logic used for restarting the pump. During a pump restart attempt, motor current over threshold can occur resulting in DTC P0C28 (Auxiliary Transmission Fluid Pump High Current). Additionally, DTC P0B07 (Auxiliary Transmission Fluid Pump Motor Phase W Low Current) was incorrectly calibrated off. A Phase W Low Current fault will result in a vehicle shutdown or no-start condition with no DTC stored and no MIL illuminated.

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

Transmission and driveline, Automatic transmission

Trouble codes named

P0B07, P0C28

Vehicles listed
CADILLAC CT6 PLUG-IN HYBRID2017, 2018 (the catalog's model; the bulletin names a series or trim of it)

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
17-NA-0662023-07-25. Service bulletin. This service bulletin provides information for automatic transmission Oil Cooler Flush and flow test.
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.
990420002L2021-08-09. Service bulletin. This service bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operation.
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.
150089004C2021-03-08. Service bulletin. This service bulletin provides technicians with updated information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
060089031F2020-12-21. Service bulletin. This service bulletin provides information on OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification.
1308116001F2020-12-07. Service bulletin. The intent of this technical bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.
16NA3612020-09-28. Service bulletin. This informational bulletin explains possible normal condition of a flare from 1st to 2nd, even if the trans had been repaired for the flare and its still noticed.
PIP57002020-02-10. Service bulletin. This Preliminary information communicates to the dealer technician that the part numbers for the internal wiring harnesses for the 8 speed RWD transmissions are not listed in the Electronic Parts Catalog. Technicians are to refer to the information provided in this document to obtain the internal wiring harness part numbers by application.
080730026F2019-09-23. Service bulletin. This informational bulletin provides information on Some vehicles may rock or move slightly forward or rearward while in Park at start up after cold soak. This condition may be accompanied by a clunk noise. This is a slight movement that is more often seen visually, rather than felt, when viewed from the outside and using the auto-start feature, if equipped.