MT-001-21

BULLETIN NOTES
This M-Tip supersedes the previously issued article(s) listed below: The changes are noted in Red.
Previous M-Tip(s):
Date(s) Issued:
MT-001/21
03/15/21
MT-001/20
07/15/20
MT-004/18
03/28/18, 07/20/18, 09/14/18
MT-017/17
11/02/17
MT-013/13
01/01/13
APPLICABLE MODEL(S)/VINS
2011-2014 Mazda2
2007-2021 Mazda6
2013-2021 CX-5
2007-2021 MX-5
2007-2021 Mazda3
2016-2021 CX-3
2007-2012 CX-7
2007-2011 RX-8
2007-2015 Mazda5
2020-2021 CX-30
2007-2021 CX-9
DESCRIPTION
If you encounter any type of electrical concern (e.g, dead battery, engine no start, DTC(s) stored...), interview the
customer before proceeding with normal Workshop Manual diagnosis. Aftermarket devices may be the cause of the
electrical concern. Ask the customer if any aftermarket devices have been installed. Below are a couple of examples of
unusual electrical concerns caused by aftermarket devices.
Example 1
Some electrical devices connected to the DLC-2 connector by insurance or mobile phone companies may cause:
• Battery discharge. The device may disrupt the CAN system battery saver mode.
• IDS/MMDS will not communicate with the vehicle due to poor DLC-2 connection. The aftermarket device may
cause DLC-2 female terminals to spread open.
• DTCs
B1041:54 - ADAPTIVE FRONT LIGHTING SYSTEM (AFS) CONTROL MODULE
B108E:04 - CENTER DISPLAY INTERNAL MALFUNCTION
C0061:54 - DSC HU/CM
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C1001:92 - FORWARD SENSING CAMERA (FSC)
C1001:97 - FORWARD SENSING CAMERA (FSC)
U300A:62 - ELECTRIC PARKING BRAKE (EPB)
U3004:17 - ACC RELAY CIRCUIT MALFUNCTION
U0415:00 - MAZDA RADAR CRUISE CONTROL (MRCC)/SMART BRAKE SUPPORT (SBS)
U0420:00 - MAZDA RADAR CRUISE CONTROL (MRCC)/SMART BRAKE SUPPORT (SBS)
Multiple DTC's (U0XXX:00 COMMUNICATION ERROR)
• If an aftermarket device is found connected to DLC-2, take a photo and attach it to the RO. Advise the customer to
remove it.
• If you determine that no aftermarket devices have been installed, continue with normal Workshop Manual
diagnosis.
Example 2
Some aftermarket cell phone chargers connected to the 12V outlet may cause an engine no start condition:
Aftermarket Cell Phone Charger
Engine Start/Stop Button
Key Warning Light
connected to 12V outlet
Amber Indicator Light Flashing
(red)
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Example 3
Some aftermarket devices that are wired to the vehicles’s wiring harness may create unusual electrical symptoms and/or
store DTCs.
Below are examples of concerns due to an aftermarket GPS tracking device wired to the power window main switch:
• Engine no start
• Battery discharge
• Main relay buzzing
Below is an example of a dim headlight. The aftermarket device changed the headlight circuit resistance, causing a dim
headlight.
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Example 4
DTC B119F:01 (TEL antenna No.1 malfunction) stored. This may be caused by an aftermarket dash cam.
The aftermarket device may cause electrical noise disturbing the reception of GPS signals.
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