DTC U029E:00 [DOSING CONTROL UNIT (SKYACTIV-D 2.2)]

id0102k1946500

DTC U029E:00	CAN communication system: NOx sensor No.2 information communication error with dosing control unit
DETECTION CONDITION	•  With the following conditions met, a communication error between the dosing control unit and NOx sensor No.2 is continued for 5 s or more. MONITORING CONDITIONS •  Battery voltage: 10.9—16 V •  Ignition switched ON (engine off or on) Note •  DTC P2BAF:00 is also stored in the PCM and the vehicle speed is restricted. •  DTC P1640:00 is also stored in the PCM. •  P0615:00 may be stored if the remaining distance to empty is 0 km {0 mile} and the engine cannot be restarted. Diagnostic support note •  This is a continuous monitor (CCM). •  The check engine light illuminates if the dosing control unit detects the above malfunction condition during the first drive cycle. •  FREEZE FRAME DATA/Snapshot data is available. •  DTC is stored in the dosing control unit memory.
FAIL-SAFE FUNCTION	•  Restricts the maximum remaining distance to empty. •  Limits the upper limit of the engine speed.
POSSIBLE CAUSE	•  NOx sensor No.2 connector or terminals malfunction •  Dosing control unit connector or terminals malfunction •  CAN communication line between NOx sensor No.2 and dosing control unit malfunction ―  NOx sensor No.2 terminal B—dosing control unit terminal BK ―  NOx sensor No.2 terminal C—dosing control unit terminal BL •  NOx sensor No.2 malfunction •  Dosing control unit malfunction
SYSTEM WIRING DIAGRAM

STEP	INSPECTION	RESULTS	ACTION
1	RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION Note •  Recording can be facilitated using the screen capture function of the PC. •  Record the FREEZE FRAME DATA/snapshot data on the repair order.	—	Go to the next step.
2	VERIFY RELATED REPAIR INFORMATION AVAILABILITY •  Verify related Service Information availability. •  Is any related Service Information available?	Yes	Perform repair or diagnosis according to the available Service Information. •  If the vehicle is not repaired, go to the next step.
		No	Go to the next step.
3	PURPOSE: VERIFY RELATED PENDING CODE AND/OR DTC •  Switch the ignition off, then ON (engine off). •  Perform the Pending Trouble Code Access Procedure and DTC Reading Procedure. (See ON-BOARD DIAGNOSTIC TEST [DOSING CONTROL UNIT (SKYACTIV-D 2.2)].) •  Is the PENDING CODE/DTC P2200:00 or U029D:00 also present?	Yes	Go to the applicable PENDING CODE or DTC inspection. (See DTC TABLE [DOSING CONTROL UNIT (SKYACTIV-D 2.2)].) Go to the next step.
		No	Go to the next step.
4	INSPECT NOx SENSOR NO.2 CONNECTOR CONDITION •  Switch the ignition off. •  Disconnect the NOx sensor No.2 connector. •  Inspect for poor connection (such as damaged/pulled-out pins, corrosion). •  Is there any malfunction?	Yes	Repair or replace the connector and/or terminals, then go to Step 7.
		No	Go to the next step.
5	INSPECT DOSING CONTROL UNIT CONNECTOR CONDITION •  Switch the ignition off. •  Disconnect the dosing control unit connector. •  Inspect for poor connection (such as damaged/pulled-out pins, corrosion). •  Is there any malfunction?	Yes	CAN communication line can be considered the cause. •  Refer to the wiring diagram and verify whether or not there is a common connector between the following terminals: ―  NOx sensor No.2 terminal B—dosing control unit terminal BK ―  NOx sensor No.2 terminal C—dosing control unit terminal BL 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 the Step 7.
		No	Go to the next step.
6	PURPOSE: DETERMINE INTEGRITY OF NOx SENSOR NO.2 •  Inspect the NOx sensor No.2. (See NOx SENSOR INSPECTION [SKYACTIV-D 2.2].) •  Is there any malfunction?	Yes	Replace the NOx sensor No.2, then go to the next step. (See NOx SENSOR REMOVAL/INSTALLATION [SKYACTIV-D 2.2].)
		No	Go to the next step.
7	VERIFY THAT ENGINE CAN BE STARTED •  Always reconnect all disconnected connectors. •  Clear the DTC from the dosing control unit memory using the M-MDS. (See CLEARING DTC [DOSING CONTROL UNIT (SKYACTIV-D 2.2)].) Note •  The engine cannot be restarted when the remaining distance to empty is 0 km {0 mile}. •  Start the engine. •  Can the engine be started?	Yes	Go to the next step.
		No	Perform the “SCR INDUCEMENT INSPECTION SERVICE FUNCTION” using the M-MDS. (See SCR INDUCEMENT INSPECTION SERVICE FUNCTION [DOSING CONTROL UNIT (SKYACTIV-D 2.2)].) Note •  When restriction of the remaining distance to empty is canceled, the SCR system warning light/SCR system warning indication turns off. Go to the next step.
8	IMPLEMENT THE REPEATABILITY VERIFICATION PROCEDURE •  Always reconnect all disconnected connectors. •  Start the engine and leave it idling for 10 s. •  Has the restriction of the remaining distance to empty been canceled?	Yes	Go to the next step.
		No	Repeat the inspection from Step 7.
9	VERIFY DTC TROUBLESHOOTING COMPLETED •  Retrieve the dosing control unit DTCs using the M-MDS. (See ON-BOARD DIAGNOSTIC TEST [DOSING CONTROL UNIT (SKYACTIV-D 2.2)].) •  Is the same Pending DTC present?	Yes	Go to the next step.
		No	Repeat the inspection from Step 1. •  If the malfunction recurs, replace the dosing control unit. (See DOSING CONTROL UNIT REMOVAL/INSTALLATION [SKYACTIV-D 2.2].) Go to the next step.
10	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 [DOSING CONTROL UNIT (SKYACTIV-D 2.2)].)
		No	DTC troubleshooting completed.