B1252 · 厂商技术资料

MAZDA · 2026-09-18

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. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT Are the following DTCs stored? YES: Proceed to next step. NO: This service…

MAZDA · 2026-08-07

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. Have the Vehicle Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU -…

MAZDA · 2026-04-18

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 Vehicle Remote functions may fail. • The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) • U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) • U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT Are the following DTCs stored? YES: Proceed to next step. • NO: This service…

MAZDA · 2026-03-04

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 Inspected" in the instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT REPAIR PROCEDURE 1. Verify the concern. 2. Check if any of the following DTCs are stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY…

MAZDA · 2026-02-27

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 instrument cluster. Additional symptoms that may occur: Connected Vehicle One Time Passcode (OTP) may fail. Connected Vehicle Remote functions may fail. The following DTC's may be stored: B1252:87-8B:TCU - COMMUNICATION ERROR WITH CONNECTIVITY MASTER UNIT (CMU) U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT

MAZDA · 2025-12-17

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 (CMU) • U0198:00-03:CMU - COMMUNICATION ERROR WITH EMERGENCY CALL UNIT/TELEMATICS COMMUNICATION UNIT

MAZDA · 2020-09-10

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: à ̄‚· B119F:01 TCU - Tel antenna No. 1 malfunctionà ̄‚· B119F:13 (TCU - TEL antenna No.1 circuit malfunction)à ̄‚· B119F:2B (CMU - GPS antenna signal circuit malfunction)à ̄‚· B1252:87 TCU - Communication error with connectivity master unit (CMU)à ̄‚· U0156:00 VCM - Communication error with connectivity master unit (CMU)à ̄‚· U0156:00 BCM - Communication error with connectivity master unit (CMU)à ̄‚· U0198:00 BCM - Communication error with emergency call unità ̄‚· U212D:00 BCM - Communication error with light control module (RH)à ̄‚· U3000:00 TCU - Telematics communication unit internal malfunctionà ̄‚· Low Voltage…

MAZDA · 2020-06-29

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:à ̄‚· B119F:01 TCU - Tel antenna No. 1 malfunction à ̄‚· B119F:13 (TCU - TEL antenna No.1 circuit malfunction) à ̄‚· B119F:2B (CMU - GPS antenna signal circuit malfunction) à ̄‚· B1252:87 TCU - Communication error with connectivity master unit (CMU) à ̄‚· U0156:00 VCM - communication error with connectivity master unit (CMU) à ̄‚· U0156:00 BCM - Communication error with connectivity master unit (CMU) à ̄‚· U0198:00 BCM - Communication error with emergency call unit à ̄‚· U212D:00 BCM - Communication error with light control module (RH) à ̄‚· U3000:00 TCU - Telematics communication unit internal malfunction à ̄‚· Low…

MAZDA · 2020-06-23

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:à ̄‚· B119F:01 TCU - Tel antenna No. 1 malfunction à ̄‚· B119F:13 (TCU - TEL antenna No.1 circuit malfunction) à ̄‚· B119F:2B (CMU - GPS antenna signal circuit malfunction) à ̄‚· B1252:87 TCU - Communication error with connectivity master unit (CMU) à ̄‚· U0156:00 VCM - communication error with connectivity master unit (CMU) à ̄‚· U0156:00 BCM - Communication error with connectivity master unit (CMU) à ̄‚· U0198:00 BCM - Communication error with emergency call unit à ̄‚· U212D:00 BCM - Communication error with light control module (RH) à ̄‚· U3000:00 TCU - Telematics communication unit internal malfunction à ̄‚· Low…

MAZDA · 2020-06-05

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: à ̄‚· B119F:01 TCU - Tel antenna No. 1 malfunction à ̄‚· B1252:87 TCU - Communication error with connectivity master unit (CMU) à ̄‚· U0156:00 VCM - communication error with connectivity master unit (CMU) à ̄‚· U0156:00 BCM - Communication error with connectivity master unit (CMU) à ̄‚· U0198:00 BCM - Communication error with emergency call unit à ̄‚· U212D:00 BCM - Communication error with light control module (RH) à ̄‚· U3000:00 TCU - Telematics communication unit internal malfunction à ̄‚· Low Voltage Battery DTCs

MAZDA · 2020-04-08

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: à ̄‚· B119F:01 TCU - Tel antenna No. 1 malfunction à ̄‚· B1252:87 TCU - Communication error with connectivity master unit (CMU) à ̄‚· U0156:00 VCM - Communication error with connectivity master unit (CMU) à ̄‚· U0156:00 BCM - Communication error with connectivity master unit (CMU) à ̄‚· U0198:00 BCM - Communication error with emergency call unit à ̄‚· U212D:00 BCM - Communication error with light control module (RH) à ̄‚· U3000:00 TCU - Telematics communication unit internal malfunction à ̄‚· Low Battery DTCs

MAZDA · 2020-02-25

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

FORD · 2018-04-10

Some 2015-2018 Mustang vehicles equipped with SYNC 3 may exhibit inoperative USB ports with the diagnostic trouble code (DTC) B1252:13 stored in the accessory protocol interface module (APIM.) This may be due to a loose connection or damage present on the cable which connects the APIM to the media hub. Follow normal Workshop Manual (WSM) diagnosis to correct this condition, while paying close attention to any damage or loose connections which may be present on this cable.

FORD · 2017-11-22

Some 2018 F-150 and Expedition vehicles equipped with SYNC without touchscreen may have DTC B1252 present in the APIM when running an APIM On-Demand Self Test. On SYNC systems without touchscreen, this DTC flag cannot be configured off, therefore the DTC may set when running an On-Demand Self Test on the APIM. If the DTC is present after an On-Demand Self Test and the customer reports no USB related symptoms, then no further repairs should be attempted. If the customer reports symptoms with USB operation refer to Workshop Manual (WSM), Section 415-00 for normal diagnostics.