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B1252 on the 2019 Mazda Mazda3

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

This code is specific to a manufacturer and is not described here. Its meaning is in the manufacturer's service information.

Bulletins for this model year that name B1252
SA-029-20g2020-10-05. Service bulletin. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored: • B119F:01 TCU - Tel antenna No. 1 malfunction• B119F:13 (TCU - TEL antenna No.1 circuit malfunction)• B119F:2B (CMU - GPS antenna signal circuit malfunction)• B1252:87 TCU - Communication error with connectivity master unit (CMU)• U0156:00 VCM - Communication error with connectivity master unit (CMU)• U0156:00 BCM - Communication error with connectivity master unit (CMU)• U0198:00 BCM - Communication error with emergency call unit• U212D:00 BCM - Communication error with light control module (RH)• U3000:00 TCU - Telematics communication unit internal malfunction• Low Voltage Battery DTCs
SA-029-20e2020-07-03. Service bulletin. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored:• B119F:01 TCU - Tel antenna No. 1 malfunction • B119F:13 (TCU - TEL antenna No.1 circuit malfunction) • B119F:2B (CMU - GPS antenna signal circuit malfunction) • B1252:87 TCU - Communication error with connectivity master unit (CMU) • U0156:00 VCM - communication error with connectivity master unit (CMU) • U0156:00 BCM - Communication error with connectivity master unit (CMU) • U0198:00 BCM - Communication error with emergency call unit • U212D:00 BCM - Communication error with light control module (RH) • U3000:00 TCU - Telematics communication unit internal malfunction • Low Voltage Battery DTCs
SA-029-20d2020-07-03. Service bulletin. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored:• B119F:01 TCU - Tel antenna No. 1 malfunction • B119F:13 (TCU - TEL antenna No.1 circuit malfunction) • B119F:2B (CMU - GPS antenna signal circuit malfunction) • B1252:87 TCU - Communication error with connectivity master unit (CMU) • U0156:00 VCM - communication error with connectivity master unit (CMU) • U0156:00 BCM - Communication error with connectivity master unit (CMU) • U0198:00 BCM - Communication error with emergency call unit • U212D:00 BCM - Communication error with light control module (RH) • U3000:00 TCU - Telematics communication unit internal malfunction • Low Voltage Battery DTCs
SA-0290-20c2020-07-03. Service bulletin. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored: • B119F:01 TCU - Tel antenna No. 1 malfunction • B1252:87 TCU - Communication error with connectivity master unit (CMU) • U0156:00 VCM - communication error with connectivity master unit (CMU) • U0156:00 BCM - Communication error with connectivity master unit (CMU) • U0198:00 BCM - Communication error with emergency call unit • U212D:00 BCM - Communication error with light control module (RH) • U3000:00 TCU - Telematics communication unit internal malfunction • Low Voltage Battery DTCs
SA-029-20a2020-05-05. Service bulletin. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored: • B119F:01 TCU - Tel antenna No. 1 malfunction • B1252:87 TCU - Communication error with connectivity master unit (CMU) • U0156:00 VCM - Communication error with connectivity master unit (CMU) • U0156:00 BCM - Communication error with connectivity master unit (CMU) • U0198:00 BCM - Communication error with emergency call unit • U212D:00 BCM - Communication error with light control module (RH) • U3000:00 TCU - Telematics communication unit internal malfunction • Low Battery DTCs
SA-029-202020-02-27. Service bulletin. Some customers may experience a "IN-VEHICLE NETWORK MALFUNCTION" warning message in the instrument cluster with one or more of the following DTC's stored: B119F:01 TCU - Tel antenna No. 1 malfunction B1252:87 TCU - Communication error with connectivity master unit (CMU) U0156:00 VCM - Communication error with connectivity master unit (CMU) U0156:00 BCM - Communication error with connectivity master unit (CMU) U0198:00 BCM - Communication error with emergency call unit U212D:00 BCM - Communication error with light control module (RH) U3000:00 TCU - Telematics communication unit internal malfunction

6 on file from NHTSA, as of 2026-10-19. See them in the bulletin list. A bulletin lists model years: read the document for which vehicles it concerns.