New Holland WorkMaster 50 Service Manual page 939

DTC 3F6-04-DOC inlet temperature sensor voltage is lower than
expected
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the Diesel Oxidation Catalyst (DOC) inlet temperature sensor B-9127.
If the ECU A-9000 detects a voltage less than 459.40 mV in the DOC inlet temperature sensor B-9127 signal circuit,
this fault will occur.
Cause:
The ECU A-9000 has detected a voltage less than 459.40 mV in the DOC inlet temperature sensor B-9127 signal
circuit. For more information regarding the technical specifications of the DOC inlet temperature sensor B-9127, see
Exhaust Gas Recirculation (EGR) temperature sensors - Technical Data (55.989).
Possible failure modes:
1. Faulty DOC inlet temperature sensor B-9127 wiring, short circuit to ground.
2. Faulty DOC inlet temperature sensor B-9127, internal failure.
3. Faulty ECU A-9000, software.
Solution:
1. Verify fault is present and active.
Use the Electronic Service Tool (EST) to check the status of this fault.
A. If the fault is present and active, continue with Step 2.
B. If the fault is no longer present or in an inactive state, the fault may be intermittent and not currently active.
Continue with Step 5.
2. Check the DOC inlet temperature sensor B-9127 for an internal failure.
Disconnect the vehicle harness (VE) from the DOC inlet temperature sensor B-9127 at connector X-9127.
Use a multimeter to measure the resistance on the DOC inlet temperature sensor B-9127 :
From
X-9127 pin 1
A. If there is between 170.2 - 849.7 Ω, leave connector X-9127 disconnected and continue to Step 3.
B. If there is not between 170.2 - 849.7 Ω, the DOC inlet temperature sensor B-9127 has failed. Replace the DOC
inlet temperature sensor B-9127.
3. Check the DOC inlet temperature sensor B-9127 vehicle harness (VE) wiring for a short circuit condition.
With the key in the OFF position, use a multimeter to perform the following continuity check on the vehicle harness
(VE) side :
From
X-9127 pin 1
X-9127 pin 1
A. If there is continuity, there is a short circuit in the DOC inlet temperature sensor B-9127 vehicle harness (VE)
wiring. Use the appropriate service manual, if necessary, to locate and repair the shorted conductor.
B. If there is no continuity, leave the connector X-9127 disconnected and continue to Step 4.
4. Check the DOC inlet temperature sensor B-9127 vehicle harness (VE) wiring for a short circuit condition.
Electrical systems - FAULT CODES
To
X-9127 pin 2
To
X-9127 pin 2
Chassis ground
47866583_ 02/12/2015
55.12 [55.DTC] / 218
Value
There should be between 170.2 -
849.7 Ω.
Value
There should be no continuity.
There should be no continuity.