New Holland WorkMaster 50 Service Manual page 1019

DTC 78B-04-Throttle valve actuator position sensor voltage is lower
than expected
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the throttle valve actuator Z-9001 position sensor signal circuit. If
the ECU A-9000 detects a voltage less than 0.25 V in the throttle valve actuator Z-9001 position sensor signal circuit,
this fault will occur.
Cause:
The ECU A-9000 has detected a voltage less than 0.25 V in the throttle valve actuator Z-9001 position sensor signal
circuit.
Possible failure modes:
1. Faulty throttle valve actuator Z-9001 wiring, short to ground condition.
2. Faulty throttle valve actuator Z-9001, 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 throttle valve actuator Z-9001 position sensor engine harness (EN) wiring for a short to ground condition.
Disconnect the engine harness (EN) from the throttle valve actuator Z-9001 at connector X-9011.
With the key in the OFF position, use a multimeter to perform the following continuity check on the engine harness
(EN) side :
From
X-9011 pin 5
X-9011 pin 5
X-9011 pin 5
A. If there is continuity, there is a short to ground condition in the throttle valve actuator Z-9001 position sensor
signal circuit in the engine harness (EN).Locate and repair the shorted conductor.
B. If there is no continuity, leave connector X-9011 disconnected and continue to Step 3.
3. Check the throttle valve actuator Z-9001 position sensor vehicle harness (VE) 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 A53
A. If there is continuity, there is a short to ground in the throttle valve actuator Z-9001 engine harness (EN) po-
sition sensor signal circuit. Use the appropriate service manual, if necessary, to locate and repair the shorted
conductor.
Electrical systems - FAULT CODES
To
Chassis ground
X-9011 pin 3
X-9011 pin 2
To
All pins in connector X-9001
47866583_ 02/12/2015
55.12 [55.DTC] / 298
Value
There should be no continuity.
There should be no continuity.
There should be no continuity.
Value
There should be no continuity.