JUNCTION BLOCK 3601846 - Caterpillar

TECHNICAL INFORMATION BULLETIN May 4, 2005
Wheel Loaders 980G II (AWH, AXG, AYT)
Component Code: 5574SUBJECT: Tilt Harness Failure Causes Tilt Sensor Service Codes
PROBLEM:
The 169-0417 Tilt Position Sensor is often erroneously replaced when the root problem is actually the kinking of the wires in the 174-4077 Tilt Sensor Harness or the 228-7285 Tilt Sensor Harness. Kinking most often occurs at the clip point that is located near the A-pin. Approximately 75% of the sensors returned for failure analysis are found to operate properly.
SOLUTION:
Note: Harness checks should be performed with the bucket grounded, engine off, and key switch in the ON position.
When Tilt Sensor Service Codes are noticed (especially MID 082 CID 0351 FMI 03, 04, or 05), check the hose covering over the tilt sensor harness for signs of kinking. Manually bend the harness at this location while monitoring the tilt sensor on the Caterpillar Electronic Technician (ET) status screen. If the sensor position parameter changes when the harness is flexed, replace the harness. Refer to Illustration 1, Illustration 2, and Illustration 3.
Note: There is a two second delay between the occurance of an open circuit and a change in the sensor parameter. A multimeter may also be used to check continuity in the three wires contained in the tilt harness (299-BK, H718-GY, and 106-WH.
If a replacement harness is installed, make sure that clamp point 1 (near the A-pin) is positioned over the green tape (located on the hose covering of the harness).
Engineering is investigating tilt harness improvements. Changes will be announced in the service magazine.
Illustration 1. Hose covering on the tilt harness is kinked between the white marks.
Illustration 2. Wires are pinched at the point of kinking resulting in an intermittent open circuit in wire H718.
Illustration 3. Check for signs of tilt harness hose kinking at clamp points 1 and 2.
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