DTC B1140:29 [START STOP UNIT]

id0902p6020600

System malfunction location

i-stop control error signal received
Detection condition
•  The starter ground circuit does not turn on even though the PCM detects an engine restart request while the engine is stopped under i-stop control, or the condition whereby an open circuit is detected for a continuous 12 s or more for a total of five times or more.
Fail-safe
—
Possible cause
•  Starter relay malfunction
•  PCM connector or terminal malfunction
•  Start stop unit connector or terminal malfunction
•  Open circuit in wiring harness between the following terminals:
―  Starter relay terminal E—PCM terminal 2AZ (SKYACTIV-G 2.0, SKYACTIV-G 2.5)
―  Starter relay terminal E—PCM terminal 2BF (SKYACTIV-D 2.2)
―  Start stop unit terminal 1D—PCM terminal 2AZ (SKYACTIV-G 2.0, SKYACTIV-G 2.5)
―  Start stop unit terminal 1D—PCM terminal 2BF (SKYACTIV-D 2.2)
―  Starter relay terminal A—Start stop unit terminal 2V
•  Start stop unit malfunction

Diagnostic Procedure

Step

Inspection

Action
1
INSPECT STARTER RELAY FOR MALFUNCTION
•  Switch the ignition to off.
•  Disconnect the negative battery cable.
•  Remove the starter relay.
•  Inspect the starter relay.
•  Is the starter relay normal?
Yes
Go to the next step.
No
Replace the starter relay, then go to Step 5.
(See RELAY LOCATION.)
2
INSPECT PCM CONNECTOR CONDITION
•  Disconnect the PCM 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 5.
3
INSPECT START STOP UNIT CONNECTOR CONDITION
•  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
Go to the next step.
No
Repair or replace the connector, then go to Step 5.
4
INSPECT STARTER RELAY CIRCUIT FOR OPEN CIRCUIT
•  Verify that the starter relay is removed.
•  Verify that the PCM and start stop unit connectors are disconnected.
•  Inspect for continuity between the following terminals (vehicle wiring harness side).
―  Starter relay terminal E—PCM terminal 2AZ (SKYACTIV-G 2.0, SKYACTIV-G 2.5)
―  Starter relay terminal E—PCM terminal 2BF (SKYACTIV-D 2.2)
―  Start stop unit terminal 1D—PCM terminal 2AZ (SKYACTIV-G 2.0, SKYACTIV-G 2.5)
―  Start stop unit terminal 1D—PCM terminal 2BF (SKYACTIV-D 2.2)
―  Starter relay terminal A—Start stop unit terminal 2V
•  Is there continuity?
Yes
Go to the next step.
No
Repair or replace the wiring harness which has an open circuit, then go to the next step.
5
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Reconnect all the disconnected connectors.
•  Reconnect the disconnected negative battery cable.
•  Clear DTC for the start stop unit using the M-MDS.
•  Perform the work of stopping the engine by i-stop control and then restarting the engine for five or more times.
•  Perform the DTC inspection for the start stop unit using the M-MDS.
•  Is DTC B1140:29 displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the start stop unit, then go to the next step.
No
Go to the next step.
6
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [START STOP UNIT].)
No
DTC troubleshooting completed.