New Holland WorkMaster 50 Service Manual page 735

DTC 131-04-Engine coolant temperature sensor voltage is lower
than expected
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the engine coolant temperature sensor B-9003 signal circuit. If the
ECU A-9000 determines that voltage is lower than expected in the engine coolant temperature sensor B-9003 signal
circuit, this fault will occur. If this fault is active, the ECU A-9000 will set the engine coolant temperature value to a
fixed replacement value of 89.96 °C (193.93 °F).
Cause:
The engine coolant temperature sensor B-9003 signal voltage is less than 198.00 mV.
Possible failure modes:
1. Faulty engine coolant temperature sensor B-9003 wiring, short to ground condition.
2. Faulty engine coolant temperature sensor B-9003, 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 coolant temperature sensor B-9003 engine harness (EN) wiring for a short to ground condition.
Disconnect the engine harness (EN) from the coolant temperature sensor B-9003 at connector X-9006.
With the key in the OFF position, use a multimeter to perform the following continuity check on the engine harness
(EN) side:
To
X-9006 pin 1
X-9006 pin 1
A. If there is no continuity, leave connector X-9006 disconnected and continue to Step 3.
B. If there is continuity, there is a short to ground condition in the coolant temperature sensor B-9003 engine
harness (EN) wiring. Locate and repair the shorted conductor.
3. Check the coolant temperature sensor B-9003 engine harness (EN) wiring for a short to ground condition.
Disconnect the engine harness (EN) from the ECU A-9000 at connector X-9001.
With the key in the OFF position, use a multimeter to perform the following continuity check on the engine harness
(EN) side:
From
X-9001 pin A57
A. If there is no continuity, leave connector X-9006 disconnected and continue to Step 4.
B. If there is continuity, there is a short circuit in the coolant temperature sensor B-9003 engine harness (EN)
wiring. Locate and repair the shorted or broken conductor.
Electrical systems - FAULT CODES
From
X-9006 pin 2
Chassis ground
To
All pins in connector X-9001
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55.12 [55.DTC] / 14
Value
There should be no continuity.
There should be no continuity.
Value
There should be no continuity.