DTC B1140:29 [START STOP UNIT]

id0902p6020600

Description

i-stop control error signal received
Detection condition
•  Start stop unit detects that the starter ground circuit does not turn on or open circuit on even though the PCM detects an engine restart request while the engine is stopped under i-stop control for 2 s or more for a total of 5 times or more.
Fail-safe function
Not applicable
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:
―  SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5
•  Starter relay terminal E—PCM terminal 2AZ
•  Start stop unit terminal 1D—PCM terminal 2AZ
•  Starter relay terminal A—Start stop unit terminal 2V
―  SKYACTIV-D 1.5, SKYACTIV-D 2.2
•  Starter relay terminal E—PCM terminal 2BF
•  Start stop unit terminal 1D—PCM terminal 2BF
•  Starter relay terminal A—Start stop unit terminal 2V
•  PCM malfunction
•  Start stop unit malfunction

Diagnostic Procedure

Step

Inspection

Action
1
INSPECT STARTER RELAY
•  Switch the ignition 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 6.
(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 6.
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 6.
4
INSPECT FOR OPEN CIRCUIT IN STARTER RELAY 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 (wiring harness-side):
―  SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5
•  Starter relay terminal E—PCM terminal 2AZ
•  Start stop unit terminal 1D—PCM terminal 2AZ
•  Starter relay terminal A—Start stop unit terminal 2V
―  SKYACTIV-D 1.5, SKYACTIV-D 2.2
•  Starter relay terminal E—PCM terminal 2BF
•  Start stop unit terminal 1D—PCM terminal 2BF
•  Starter relay terminal A—Start stop unit terminal 2V
•  Is there continuity?
Yes
Go to the next step.
No
Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals:
•  SKYACTIV-G 1.5, SKYACTIV-G 2.0, SKYACTIV-G 2.5
―  Starter relay terminal E—PCM terminal 2AZ
―  Start stop unit terminal 1D—PCM terminal 2AZ
―  Starter relay terminal A—Start stop unit terminal 2V
•  SKYACTIV-D 1.5, SKYACTIV-D 2.2
―  Starter relay terminal E—PCM terminal 2BF
―  Start stop unit terminal 1D—PCM terminal 2BF
―  Starter relay terminal A—Start stop unit terminal 2V
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 an open circuit.
•  Repair or replace the malfunctioning part.
If there is no common connector:
•  Repair or replace the wiring harness which has an open circuit.
Go to Step 6.
5
VERIFY IF MALFUNCTIONING LOCATION IS PCM DEPENDING ON REPEATABILITY
•  Always reconnect all disconnected connectors.
•  Reconnect the negative battery cable.
•  Clear the 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 5 times or more.
•  Retrieve the start stop unit DTCs using the M-MDS.
•  Is the same DTC displayed?
Yes
Repeat the inspection from Step 1.
•  If the malfunction recurs, replace the start stop unit.
Go to the next step.
No
Go to Step 7.
6
VERIFY THAT REPAIRS HAVE BEEN COMPLETED
•  Always reconnect all disconnected connectors.
•  Reconnect the negative battery cable.
•  Clear the 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 5 times or more.
•  Retrieve the start stop unit DTCs using the M-MDS.
•  Is the same DTC displayed?
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.
7
VERIFY IF OTHER DTCs DISPLAYED
•  Are any other DTCs displayed?
Yes
Repair or replace the malfunctioning part according to the applicable DTC troubleshooting.
(See DTC TABLE [START STOP UNIT].)
No
DTC troubleshooting completed.