DTC B121E:12 [MAZDA ERA-GLONASS CONTROL MODULE]

id0902r6080900


Without i-stop

Description

ACC output circuit malfunction
Detection condition
The Mazda ERA-GLONASS control module detected a short to power supply in the ACC output circuit.
Fail-safe function
Not applicable
Possible cause
•  DTCs are stored in the start stop unit.
•  ACC relay malfunction
•  Tuner and amp unit (TAU) connector or terminal malfunction (with center display)
•  Audio unit connector or terminal malfunction (without center display)
•  Bluetooth® unit connector or terminal malfunction (without center display)
•  Mazda ERA-GLONASS control module connector or terminal malfunction
•  Short to power supply in wiring harness between the following terminals:
―  Mazda ERA-GLONASS control module terminal 1X and ACC relay terminal D
―  Mazda ERA-GLONASS control module terminal 1Z and tuner and amp unit (TAU) terminal 2R (with center display)
―  Mazda ERA-GLONASS control module terminal 1Z and audio unit terminal 1R (without center display)
―  Mazda ERA-GLONASS control module terminal 1Z and Bluetooth® unit terminal AB (without center display)
•  Tuner and amp unit (TAU) malfunction (with center display)
•  Audio unit malfunction (without center display)
•  Bluetooth® unit malfunction (without center display)
•  Mazda ERA-GLONASS control module malfunction

Diagnostic Procedure

Step

Inspection

Action
1
INSPECT ACC RELAY
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Remove the ACC relay.
•  Inspect the ACC relay.
•  Is the ACC relay normal?
Yes
Go to the next step.
No
Replace the ACC relay, then go to Step 12.
(See RELAY LOCATION.)
2
VERIFY START STOP UNIT CONTROL MODULE DTCs
•  Retrieve the start stop unit DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [START STOP UNIT].)
No
Go to the next step.
3
INSPECT MAZDA ERA-GLONASS CONTROL MODULE CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the Mazda ERA-GLONASS control module connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 12.
4
INSPECT MAZDA ERA-GLONASS CONTROL MODULE POWER SUPPLY (ACC) CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify Mazda ERA-GLONASS control module connector is disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on)
•  Measure the voltage at the Mazda ERA-GLONASS control module terminal 1X (wiring harness-side).
•  Is the voltage 0 V?
Yes
With center display
•  Go to the next step.
Without center display
•  Go to Step 8.
No
Refer to the wiring diagram and verify if there is a common connector between the following terminals.
•  Mazda ERA-GLONASS control module terminal 1X and ACC relay terminal D
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to power supply.
Go to Step 12.
5
INSPECT TUNER AND AMP UNIT (TAU) CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the tuner and amp unit (TAU) connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 12.
6
INSPECT MAZDA ERA-GLONASS CONTROL MODULE ACC OUTPUT CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the tuner and amp unit (TAU) and Mazda ERA-GLONASS control module connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on)
•  Measure the voltage at the Mazda ERA-GLONASS control module terminal 1Z (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify if there is a common connector between the following terminals.
•  Mazda ERA-GLONASS control module terminal 1Z and tuner and amp unit (TAU) terminal 2R
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to power supply.
Go to Step 12.
7
PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING LOCATION IS TUNER AND AMP UNIT (TAU)
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Always reconnect all disconnected connectors.
•  Reconnect the negative battery cable.
•  Clear the DTC for the Mazda ERA-GLONASS control module using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 25 s or more.
•  Perform the DTC inspection for the Mazda ERA-GLONASS control module using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the tuner and amp unit (TAU), then go to Step 12.
(See TUNER AND AMP UNIT (TAU) REMOVAL/INSTALLATION.)
No
Go to Step 13.
8
INSPECT AUDIO UNIT AND Bluetooth® UNIT CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the audio unit connector.
•  Disconnect the Bluetooth® unit connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 12.
9
INSPECT MAZDA ERA-GLONASS CONTROL MODULE ACC OUTPUT CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the audio unit, Bluetooth® unit and Mazda ERA-GLONASS control module connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on)
•  Measure the voltage at the Mazda ERA-GLONASS control module terminal 1Z (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify if there is a common connector between the following terminals.
•  Mazda ERA-GLONASS control module terminal 1Z and audio unit terminal 1R
•  Mazda ERA-GLONASS control module terminal 1Z and Bluetooth® unit terminal AB
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to power supply.
Go to Step 12.
10
VERIFY AUDIO UNIT DTCs
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Always reconnect all disconnected connectors.
•  Reconnect the negative battery cable.
•  Clear the DTC for the audio unit.
•  Perform the DTC inspection for the audio unit using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [AUDIO].)
No
Go to the next step.
11
PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING LOCATION IS Bluetooth® UNIT
•  Clear the DTC for the Mazda ERA-GLONASS control module using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 25 s or more.
•  Perform the DTC inspection for the Mazda ERA-GLONASS control module using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the Bluetooth® unit, then go to the next step.
(See Bluetooth® UNIT REMOVAL/INSTALLATION.)
No
Go to Step 13.
12
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Clear the DTC for the Mazda ERA-GLONASS control module using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 25 s or more.
•  Perform the DTC inspection for the Mazda ERA-GLONASS control module using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the Mazda ERA-GLONASS control module.
Go to the next step.
No
Go to the next step.
13
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
(See DTC TABLE [MAZDA ERA-GLONASS CONTROL MODULE])
No
DTC troubleshooting completed.


With i-stop

Description

ACC output circuit malfunction
Detection condition
The Mazda ERA-GLONASS control module detected a short to power supply in the ACC output circuit.
Fail-safe function
Not applicable
Possible cause
•  DTCs are stored in the start stop unit.
•  Ignition relay (ACC_STAB) malfunction
•  Mazda ERA-GLONASS control module connector or terminal malfunction
•  Tuner and amp unit (TAU) connector or terminal malfunction (with center display)
•  Audio unit connector or terminal malfunction (without center display)
•  Bluetooth® unit connector or terminal malfunction (without center display)
•  Short to power supply in wiring harness between the following terminals:
―  Mazda ERA-GLONASS control module terminal 1X and ignition relay (ACC_STAB) terminal C
―  Mazda ERA-GLONASS control module terminal 1Z and tuner and amp unit (TAU) terminal 2R (with center display)
―  Mazda ERA-GLONASS control module terminal 1Z and audio unit terminal 1R (without center display)
―  Mazda ERA-GLONASS control module terminal 1Z and Bluetooth® unit terminal AB (without center display)
•  Tuner and amp unit (TAU) malfunction (with center display)
•  Audio unit malfunction (without center display)
•  Bluetooth® unit malfunction (without center display)
•  Mazda ERA-GLONASS control module malfunction

Diagnostic Procedure

Step

Inspection

Action
1
INSPECT IGNITION RELAY (ACC_STAB)
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Remove the ignition relay (ACC_STAB).
•  Inspect the ignition relay (ACC_STAB).
•  Is the ignition relay (ACC_STAB) normal?
Yes
Go to the next step.
No
Replace the ignition relay (ACC_STAB), then go to Step 12.
(See RELAY LOCATION.)
2
VERIFY START STOP UNIT CONTROL MODULE DTCs
•  Retrieve the start stop unit DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [START STOP UNIT].)
No
Go to the next step.
3
INSPECT MAZDA ERA-GLONASS CONTROL MODULE CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the Mazda ERA-GLONASS control module connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 12.
4
INSPECT MAZDA ERA-GLONASS CONTROL MODULE POWER SUPPLY (ACC) CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify Mazda ERA-GLONASS control module connector is disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on)
•  Measure the voltage at the Mazda ERA-GLONASS control module terminal 1X (wiring harness-side).
•  Is the voltage 0 V?
Yes
With center display
•  Go to the next step.
Without center display
•  Go to Step 8.
No
Refer to the wiring diagram and verify if there is a common connector between the following terminals.
•  Mazda ERA-GLONASS control module terminal 1X and ignition relay (ACC_STAB) terminal C
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to power supply.
Go to Step 12.
5
INSPECT TUNER AND AMP UNIT (TAU) CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the tuner and amp unit (TAU) connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 12.
6
INSPECT MAZDA ERA-GLONASS CONTROL MODULE ACC OUTPUT CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the tuner and amp unit (TAU) and Mazda ERA-GLONASS control module connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on)
•  Measure the voltage at the Mazda ERA-GLONASS control module terminal 1Z (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify if there is a common connector between the following terminals.
•  Mazda ERA-GLONASS control module terminal 1Z and tuner and amp unit (TAU) terminal 2R
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to power supply to determine the malfunctioning location.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to power supply.
Go to Step 12.
7
PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING LOCATION IS TUNER AND AMP UNIT (TAU)
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Always reconnect all disconnected connectors.
•  Reconnect the negative battery cable.
•  Clear the DTC for the Mazda ERA-GLONASS control module using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 25 s or more.
•  Perform the DTC inspection for the Mazda ERA-GLONASS control module using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the tuner and amp unit (TAU), then go to Step 12.
(See TUNER AND AMP UNIT (TAU) REMOVAL/INSTALLATION.)
No
Go to Step 13.
8
INSPECT AUDIO UNIT AND Bluetooth® UNIT CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Disconnect the audio unit connector.
•  Disconnect the Bluetooth® unit connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Go to the next step.
No
Repair or replace the connector, then go to Step 12.
9
INSPECT MAZDA ERA-GLONASS CONTROL MODULE ACC OUTPUT CIRCUIT FOR SHORT TO POWER SUPPLY
•  Verify that the audio unit, Bluetooth® unit and Mazda ERA-GLONASS control module connectors are disconnected.
•  Connect the negative battery cable.
•  Switch the ignition ON (engine off or on)
•  Measure the voltage at the Mazda ERA-GLONASS control module terminal 1Z (wiring harness-side).
•  Is the voltage 0 V?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify if there is a common connector between the following terminals.
•  Mazda ERA-GLONASS control module terminal 1Z and audio unit terminal 1R
•  Mazda ERA-GLONASS control module terminal 1Z and Bluetooth® unit terminal AB
If there is a common connector:
•  Inspect the common connector and terminals for corrosion, damage, or disconnection and the common wiring harnesses for short to ground to determine the malfunctioning location.
•  Repair or replace the malfunctioning location.
If there is no common connector:
•  Repair or replace the wiring harness which is shorted to ground.
Go to Step 12.
10
VERIFY AUDIO UNIT DTCs
•  Switch the ignition off.
•  Disconnect the negative battery cable.
•  Always reconnect all disconnected connectors.
•  Reconnect the negative battery cable.
•  Clear the DTC for the audio unit.
•  Perform the DTC inspection for the audio unit using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [AUDIO].)
No
Go to the next step.
11
PERFORM DTC INSPECTION AND VERIFY IF MALFUNCTIONING LOCATION IS Bluetooth® UNIT
•  Clear the DTC for the Mazda ERA-GLONASS control module using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 25 s or more.
•  Perform the DTC inspection for the Mazda ERA-GLONASS control module using the M-MDS.
•  Is the same DTC displayed?
Yes
Replace the Bluetooth® unit, then go to the next step.
(See Bluetooth® UNIT REMOVAL/INSTALLATION.)
No
Go to Step 13.
12
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Clear the DTC for the Mazda ERA-GLONASS control module using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 25 s or more.
•  Perform the DTC inspection for the Mazda ERA-GLONASS control module using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the Mazda ERA-GLONASS control module.
Go to the next step.
No
Go to the next step.
13
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair the malfunctioning location according to the applicable DTC troubleshooting.
(See DTC TABLE [MAZDA ERA-GLONASS CONTROL MODULE])
No
DTC troubleshooting completed.