New Holland WorkMaster 50 Service Manual page 1015

DTC 72C-03-Glow plug 2 control circuit shorted to ground
Control Module : ECU
Context:
For information regarding the functional operation of the glow plug control module Z-9101 see Glow plug system
Glow plug control module - Overview – Glow plug control module (55.202). The Engine Control Unit (ECU)
A-9000 requests operation of the glow plug control module Z-9101 via a Pulse Width Modulated (PWM) control circuit
and monitors the status of possible electrical defects via a diagnostic feedback signal from the glow plug control
module Z-9101. If the ECU A-9000 is notified of a short circuit condition in the glow plug 2 R-9002 circuit, this fault
will occur.
Cause:
The glow plug control module Z-9101 has communicated to the ECU A-9000, via a diagnostic connection, that a short
circuit condition exists in the glow plug 2 R-9002 circuit.
Possible failure modes:
1. Faulty glow plug 2 R-9002, internal failure.
2. Faulty glow plug 2 R-9002 control circuit wiring, shorted to ground.
3. Faulty ECU A-9000, software.
Solution:
1. Verify that the 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 6.
2. Check the glow plug for a short to ground condition.
Disconnect the engine harness (EN) from glow plug 2 R-9002 at connector X-9035.
Use a multimeter to check on the component for a grounded (shorted) condition :
From
X-9035 pin 1
A. If there is greater than 0.2 Ω, leave connector X-9035 disconnected and continue with Step 3.
B. If there is less than 0.2 Ω, the glow plug 2 R-9002 has failed internally, replace the glow plug.
3. Check the glow plug 2 R-9002 control circuit for a short to ground condition.
With the key switch in the OFF position, use a multimeter to check for continuity on the engine harness (EN) side :
From
X-9035 pin 1
A. If there is continuity, continue with Step 4.
B. If there is no continuity, continue with Step 5.
4. Locate the short to ground condition.
Carefully disconnect the vehicle harness (VE) from the glow plug control module Z-9101 at connector X-9113.
With the key switch in the OFF position, use a multimeter to check for continuity on the vehicle harness (VE) side :
Electrical systems - FAULT CODES
To
chassis ground
To
chassis ground
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Result
There should be 0.2 - 5.0 Ω.
Result
There should be no continuity.