What does this code mean?
The wording below belongs to the named make and communication. Match the complete code, reporting module, model year and engine before applying it.
A code identifies a detected condition, not a part that must automatically be replaced.
Manufacturer communications
42Original wording in English
MAZDA
Reported code forms U0198:00
DESCRIPTION Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail.…
MAZDA
Reported code forms U0198:00
This Service Alert supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-012/26 04/17/26, 03/04/26 and 02/26/2026 DESCRIPTION Some customers may experience a message "TCU Malfunction.…
MAZDA
Reported code forms U0198:00
Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. • Connected…
MAZDA
Reported code forms U0198:00
This Service Alert supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-012/26 02/26/2026 DESCRIPTION Some customers may experience a message "TCU Malfunction. Have the Vehicle…
MAZDA
Reported code forms U0198:00
This Service Alert supersedes the previously issued SA(s) listed below. The changes are noted in Red. SA-060/25 12/16/25 Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the…
MAZDA
Reported code forms U0198:00
Some customers may experience a message "TCU Malfunction. Have the Vehicle Inspected" in the instrument cluster. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT…
Check vehicle applicability
168A listed vehicle is a research lead. Confirm the engine, production range and software in the manufacturer's information.
Historical vehicle association; OBD-II compatibility is not established by this record.
| Make | Model | Model year |
|---|---|---|
| Buick | ENCORE | 2020 |
| Buick | ENCORE GX | 2020 |
| Cadillac | ESCALADE | 2020 |
| Cadillac | ESCALADE | 2019 |
| Cadillac | ESCALADE | 2018 |
| Cadillac | ESCALADE | 2017 |
| Chevrolet | EQUINOX | 2015 |
| Chevrolet | EQUINOX | 2014 |
| Chevrolet | EQUINOX | 2013 |
| Chevrolet | EQUINOX | 2012 |
| Chevrolet | EQUINOX | 2011 |
| Chevrolet | EQUINOX | 2010 |
Historical records · 1 · Historical vehicle association; OBD-II compatibility is not established by this record.
Before replacing a part
Record codes and freeze-frame data. Check battery condition, related codes and visible wiring or hose damage. Follow the vehicle's diagnostic procedure and test results before replacing parts.
Can I keep driving?
A code alone cannot establish whether driving is safe. A flashing malfunction light, severe shaking, overheating, oil-pressure warning or loss of braking or steering needs prompt attention. Stop in a safe place and seek assistance when control or engine safety is affected. Follow the vehicle handbook.