Component DTC Code Error code description
Post DPF
P229E-93 NOx Sensor Bank 1 Sensor 2 - No Operation.
NOx Sensor2
Sensor location Sensor view
It is located after DPF system on exhaust pipe.
Error occurring Effect on the
Probable causes Remedial actions
condition vehicle
Error occurs if, •Increase NOx •Wiring Harness 1. Check loose connection of sensor connector.
•Incorrect emissions. • NOx sensor2. 2. Connect Breakout harness & Box and
voltage at NOx •Fuel • EMS Check the continuity between ACM and EMS to
sensor 2 economy not NOx sensor.
connector consistent. 3. Check voltage b/w sensor connector pins to
•Calibration •Excessive ground.
value out of smoke. 4. Check resistance b/w sensor pins.
range 5. Remove EMS & ACM connectors and check
resistance b/w ECU pins.
5. Check resistance between CAN4 connector
Pin 6 & 14.
6. Use the diagnostic tool & read the live
parameter, and select parameters P1KNJ:
Exhaust temp & P1RJT: NOx sensor and raise
the exhaust temp. to 350-400 deg.C and check
NOx sensor value there must be some value
show in ppm if not then replace the sensor.
7. Replace the sensor.
8. If problems not solved then change EMS
Connector view
ECU “B” connector Sensor connector
Circuit diagram
Circuit description:
From Pin No. To pin no Wiring Color Code Wiring Function
EB:36 1 0.5 L CAN4 High Signal
EB:35 2 0.5 G CAN4 Low Signal
Ground 3 0.75 BR Ground
ACM ECU 88 4 0.75 R/L Supply
Circuit Inspection
Pre- From pin
Type of inspection To pin no Expected result
condition no
1 EB:36
2 EB:35
Continuity Ignition Off Beep sound from Multimeter
3 Ground
4 ACM ECU 88
Sensor connector Pin 1 to 2 50 - 70 ohms
EB: 35 EB: 36 120 ohms
ACM:82 ACM:90 120 ohms
Resistance Ignition Off
Sensor Pin 1 to 4 110 ohms
Sensor Pin 3 to 4 450 ohms
Sensor Pin 2 to 3 250 ohms
1 Ground 2.0 – 4.0 V
Voltage Ignition On 2 Ground 1.0 – 3.0 V
4 Ground 24.0 V
Breakout Connection:-
Visual inspection (Electrical):
1. Check that the connectors are properly connected and locked into position
2. Disconnect and check the component connector
3. Inspect pins and terminals for oxidations or corrosion
4. Ensure that the pins and terminals are locked into the connectors and that they are not pushed
back out of the sockets
5. Check the pins and terminal are not damaged (which can cause poor connection)
Visual inspection (Mechanical):
1. Check sensor installation position
2. Check dust particles nearby sensor
3. Check proper torqueing of the sensor bolts.
4. Check AdBlue concentration in the fluid. Check Dosing valve & Pump unit.
5. Check the exhaust system.
Inspection using Fault code status check:
A) If there is a Short circuit DTC in the ECU, to identify whether the fault is in wiring harness or the
sensor, disconnect the component connector, (creating open circuit) and re-read fault code
status to see if status changes (where applicable).
o If the fault code changes i.e. open circuit DTC occurs, issue is with the internal circuit of
the component
o If the fault code does not change, issue is with the wiring harness
B) Connect a new sensor with the ECU and check whether the fault gets erased
o If the fault code gets erased, issue is with the internal circuit of the component
o If the fault code does not change, issue is with the wiring harness.
