New Holland CX720 Repair Manual page 1808

0408.3-ENGINE OVERSPEED, SHORTED TO HIGH SOURCE
(SERVICE TOOL FAULT CODE 208) (B.10.A.95.80 - G.30.B.54)
CX840
0408.3 - ENGINE OVERSPEED, SHORTED TO HIGH SOURCE (SERVICE TOOL FAULT CODE 208)
Context:
Engine enabled - no restriction on fuel or speed
Cause:
Engine has exceeded the overspeed limit
Possible failure modes:
1. Speed sensor faulty
2. Faulty Vehicle electronic control unit (CCM2) software or hardware
Solution:
1. Check the engine speed sensor.
A. Using a suitable multi-meter check across the speed sensor terminals for a short circuit or an open circuit
and between each terminal for a short to ground. If any of the above conditions exist replace the engine
speed sensor. The sensor resistance value is 880 - 920 Ω between the terminals 1 and 2.
B. If the sensor appears to be okay continue with step 2.
2. Check CCM2 controller
A. Check the hardware of the CCM2 controller. Remove and inspect the connectors, check the installation
of the controller to the vehicle frame, check the ground connections for the controller and check the power
feeds from fuse F-36 and fuse F-37. Repair / replace any damaged items.
B. Check the software installed in the controller on the infoview screen. If the infoview is indicating software
installed and has no CCM2 ECU errors, download the correct level software again into the controller.
Operate the engine, if the error re-occurs substitute the CCM2 controller.
NOTE: If CCM2 ECU errors are indicated rectIfy these errors first. Refer to the CCM2 fault code charts.
Series 1206 and above
Wiring harness - Electrical schematic frame 04 (A.30.A.88-C.20.E.04)
Series 1206-1347
Wiring harness - Electrical schematic frame 21 (A.30.A.88-C.20.E.21)
Series 1348 and above
Wiring harness - Electrical schematic frame 28 (A.30.A.88-C.20.E.28)
POWER PRODUCTION - ENGINE
2 4/7/2006
B.10.A / 262