New Holland WorkMaster 50 Service Manual page 954

DTC 48D-12-Throttle valve actuator control circuit over temperature
Control Module : ECU
Context:
The Engine Control Unit (ECU) A-9000 monitors the throttle valve actuator Z-9001 output 1 and output 2 h-bridge
circuits. If the ECU A-9000 detects an over temperature/current condition in the throttle valve actuator Z-9001 h-bridge
circuit, this fault will occur.
Cause:
The ECU A-9000 has detected an over temperature/current condition in the throttle valve actuator Z-9001 h-bridge
circuit.
Possible failure modes:
1. Faulty throttle valve actuator Z-9001 wiring, short to ground condition.
2. Faulty throttle valve actuator Z-9001 wiring, short to high source condition.
3. Faulty throttle valve actuator Z-9001, internal failure.
4. 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 7.
2. Check the throttle valve actuator Z-9001 h-bridge wiring for a short to battery condition.
Disconnect the engine harness (EN) from the throttle valve actuator Z-9001 at connector X-9011.
Disconnect the engine harness (EN) from the ECU A-9000 at connector X-9001.
With the key in the ON position, use a multimeter to perform the following voltage check for a short to battery on
the engine harness (EN) side :
From
X-9011 pin 6
X-9011 pin 2
A. If there is voltage, there is a short to battery in the throttle valve actuator Z-9001 h-bridge circuit. Use the
appropriate service manual, if necessary, to locate and repair the shorted conductor.
B. If there is no voltage, leave connectors X-9011 and X-9001 disconnected and continue to Step 3.
3. Check the throttle valve actuator Z-9001 h-bridge wiring for a short to ground condition.
With the key in the OFF position, use a multimeter to perform the following continuity check for a short to ground
on the engine harness (EN) side :
From
X-9011 pin 6
X-9011 pin 2
A. If there is continuity, there is a short to ground in the throttle valve actuator Z-9001 h-bridge circuit. Use the
appropriate service manual, if necessary, to locate and repair the shorted conductor.
Electrical systems - FAULT CODES
To
Chassis ground
Chassis ground
To
Chassis ground
Chassis ground
47866583_ 02/12/2015
55.12 [55.DTC] / 233
Value
There should be no voltage.
There should be no voltage.
Value
There should be no continuity.
There should be no continuity.