CYLINDER AS 8U1281 - Caterpillar

Table 1
J1939 Code and Description CDL Code and Description Comments
3216-9
Aftertreatment #1 Intake NOx : Abnormal Update Rate 3002-9
Engine Exhaust NOx Level Sensor : Abnormal Update Rate There is a communication problem between the inlet NOx sensor and the aftertreatment ECM.
3216-12
Aftertreatment #1 Intake NOx : Failure 3002-12
Engine Exhaust NOx Level Sensor : Failure A failed intake NOx sensor has been detected.
3226-9
Aftertreatment #1 Outlet NOx : Abnormal Update Rate 3609-9
Aftertreatment #1 Outlet #1 NOx Level Sensor : Abnormal Update Rate There is a communication problem between the outlet NOx sensor #1 and the aftertreatment ECM.
3226-12
Aftertreatment #1 Outlet NOx : Failure 3609-12
Aftertreatment #1 Outlet #1 NOx Level Sensor : Failure A failed outlet NOx sensor has been detected.
3265-9
Aftertreatment #2 Outlet NOx : Abnormal Update Rate 3610-9
Aftertreatment #1 Outlet #2 NOx Level Sensor : Abnormal Update Rate There is a communication problem between the outlet NOx sensor #2 and the aftertreatment ECM.
3265-12
Aftertreatment #2 Outlet NOx : Failure 3610-12
Aftertreatment #1 Outlet #2 NOx Level Sensor : Failure A failed intake NOx sensor has been detected.
Illustration 1 g03711103Probable Causes
Codes
Sensor
Sensor connector
Data link Recommended Actions
Table 2
Troubleshooting Test Steps Values Results
1. Check for Codes
A. Establish communication between Cat® Electronic Technician (ET) and the ECM.
B. Turn the DC breaker to the ON position.
C. Look for active codes.
Diagnostic Codes
Result: A -12 code is active.
Repair: Replace the failed NOx sensor.
Refer to Special Instruction,, REHS8151 for special handling instructions.
Proceed to Test Step 6.
Result: A -9 code is active.
Check to ensure the NOx sensors are connected to the wiring harness.
Proceed to Test Step 2.
2. Inspect the NOx Sensor Power Supply Wiring
A. Turn the DC breaker to the OFF position.
B. Disconnect the suspect NOx sensor from the wiring harness.
C. Turn the DC breaker to the ON position.
D. Measure the voltage between pin 1 (SUPPLY) and pin 4 (RETURN) on the suspect NOx sensor connector.
Battery Voltage
Result: Battery voltage is present at the NOx sensor connector.
Proceed to Test Step 5.
Result: Battery voltage is not present at the NOx sensor connector.
If the problem is not resolved, proceed to Test Step 3.
3. Check for Power at the Suspect NOx Sensor Connector
A. Turn the DC breaker to the OFF position.
B. Disconnect the suspect NOx sensor from the wiring harness.
C. Turn the DC beaker to the ON position.
D. Measure the voltage between pin 1 (SUPPLY) on the suspect NOx sensor connector and a known good ground.
Battery Voltage
Result: The voltage is equal to battery voltage.
Proceed to Test Step 4.
Result: The voltage is not equal to battery voltage.
There is a problem with the power supply circuit between the suspect NOx sensor connector and the aftertreatment ECM. Refer to the appropriate schematic.
Repair: Repair or replace the wiring harness as necessary.
If the problem is not resolved, proceed to Test Step 6.
4. Check the Ground at the Suspect NOx Sensor Connector
A. Turn the DC breaker to the OFF position.
B. Disconnect the suspect NOx sensor from the wiring harness.
C. Measure the resistance between pin 4 (RETURN) on the suspect NOx sensor connector and a known good ground.
Less than 10 ohms
Result: More than 10 ohms of resistance