DTC U3003:16 [START STOP UNIT]


id0902p6024900

Description

Start stop unit power supply voltage (terminal 1A) low input

Detection condition
•  Start stop unit power supply circuit voltage (terminal 1A) of 5V or more, less than 8.5 V is detected for 5 s or more.
Fail-safe
•  The door lock and unlock may not operate using the advanced keyless entry system. (With advanced keyless entry system)
•  The door lock and unlock may not operate using the keyless entry system. (With keyless entry system)
•  When starting the engine, it may be necessary to use the method for starting the engine when the transmitter battery is dead.
Possible cause
•  DTCs are stored in the PCM.
•  DTCs are stored in the DC-DC converter (i-ELOOP).
―  DC-DC converter (i-ELOOP) connector or terminal malfunction
―  DC-DC converter (i-ELOOP) malfunction
•  Battery malfunction
•  Generator malfunction
•  Start stop unit connector or terminal malfunction
•  Start stop unit power supply circuit (terminal 1A) malfunction
―  Without i-ELOOP:
•  Malfunction between battery positive terminal and start stop unit terminal 1A
―  With i-ELOOP:
•  Malfunction between battery DC-DC converter (i-ELOOP) terminal 4A and start stop unit terminal 1A
•  Start stop unit malfunction

Diagnostic Procedure

Step

Inspection

Action

1
VERIFY PCM DTCs
•  Retrieve the PCM DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
Without i-ELOOP:
•  Go to Step 3.
With i-ELOOP:
•  Go to the next step.
2
VERIFY DC-DC CONVERTER (i-ELOOP) DTCs
•  Retrieve the DC-DC converter (i-ELOOP) DTCs using the M-MDS.
•  Are any DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
Go to the next step.
3
INSPECT BATTERY
•  Inspect the battery.
•  Is the battery normal?
Yes
Go to the next step.
No
Recharge or replace the battery, then go to Step 8.
4
INSPECT GENERATOR
•  Is the generator normal?
Yes
Go to the next step.
No
Replace the generator, then go to Step 8.
5
INSPECT START STOP UNIT CONNECTOR CONDITION
•  Switch the ignition off.
•  Disconnect the negative battery terminal.
•  Disconnect the start stop unit connector.
•  Inspect the connector engagement and connection condition and inspect the terminals for damage, deformation, corrosion, or disconnection.
•  Is the connector normal?
Yes
Without i-ELOOP:
•  Go to the next step.
With i-ELOOP:
•  Go to Step 7.
No
Repair or replace the connector, then go to Step 8.
6
VERIFY START STOP UNIT POWER SUPPLY VOLTAGE (TERMINAL 1A)
•  Always reconnect all disconnected connectors.
•  Connect the negative battery terminal.
•  Display PID VPWR_B1 using the M-MDS.
•  Is the voltage 5 V or more or less than 8.5 V?
Yes
Refer to the wiring diagram and verify whether or not there is a common connector between battery positive terminal and start stop unit terminal 1A.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a malfunction.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Inspect the wiring harness battery positive terminal and start stop unit terminal 1A.
―  If there is any malfunction:
•  Repair or replace the wiring harness.
―  If there is no malfunction:
•  Replace the start stop unit.
Go to Step 8.
No
Go to Step 8.
7
VERIFY START STOP UNIT POWER SUPPLY VOLTAGE (TERMINAL 1A)
•  Always reconnect all disconnected connectors.
•  Connect the negative battery terminal.
•  Display PID VPWR_B1 using the M-MDS.
•  Is the voltage 5 V or more or less than 8.5 V?
Yes
Disconnect the service plug.
Refer to the wiring diagram and verify whether or not there is a common connector between DC-DC converter (i-ELOOP) terminal 4A and start stop unit terminal 1A.
If there is a common connector:
•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a malfunction.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Inspect the wiring harness DC-DC converter (i-ELOOP) terminal 4A and start stop unit terminal 1A.
―  If there is any malfunction:
•  Repair or replace the wiring harness.
―  If there is no malfunction:
•  Replace the start stop unit.
Connect the service plug, then go to the next step.
No
Go to the next step.
8
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Always reconnect all disconnected connectors.
•  Connect the negative battery terminal.
•  Clear the DTC for the start stop unit using the M-MDS.
•  Switch the ignition ON (engine off or on) and wait for 5 s or more.
•  Retrieve the start stop unit DTCs using the M-MDS.
•  Is the same Pending DTC present?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the start stop unit.
Go to the next step.
No
Go to the next step.
9
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
No
DTC troubleshooting completed.