Case IH AFX8010 Repair Manual page 1803

BODY AND STRUCTURE - SAFETY SECURITY ACCESSORIES Safety
Sensing system Rear ladder sensor - Short circuit to B+
(E.50.B.95.80 - G.30.B.54)
AFX8010
E0026-03 - Rear Ladder Sensor
Cause:
The rear ladder sensor (B-22) circuit is shorted to a higher than normal voltage source.
Possible failure modes:
1. Sensor supply wiring shorted to 12 volts.
2. Controller internal failure (internal regulator failure).
Solution:
1.
Enter the Universal Display Plus "DIAG" screen. Select the "GRAIN HANDLING" or "THRESHING" sort menu,
and select "REAR LADDER SEN" to check the voltage range.
The proper voltage for sensor when rear ladder is up is 0.5 - 3.9 volts
The proper voltage for sensor when rear ladder is down is 3.9 - 4.9 volts
The proper voltage with sensor disconnected is 4.9 - 5.2 volts.
A. If the voltage reading is high out of range (>5.2 volts), continue with Step 2.
B. If the voltage reading is within the proper limits, the shorted wire may not be powered up at this time.
Continue the troubleshooting at Step 5.
NOTE: Visually inspect the wiring harness and connectors. Verify that the connector was fully installed.
Inspect the terminals and wires at the connector for pushed back or corroded terminals or damaged wires.
2. Disconnect the rear ladder sensor connector X251.
A. If the voltage drops to 4.9 - 5.2 volts, the short is in the sensor or sensor wiring. Replace the sensor.
B. If the voltage remains high, continue with Step 3.
3. Disconnect the straw hood rear (SH) harness from the straw hood front (SW) harness at connector X071.
A. If the voltage drops to 4.9 - 5.2 volts, the short is in the straw hood (SH) harness between connector
X071 pin 11 and connector X251 pin 2 wire 570 yellow. Locate the short and repair.
B. If the voltage remains high, continue with Step 4.
4. Disconnect the straw hood front (SW) harness from the main frame (MF) harness at connector X024.
A. If the voltage drops to 4.9 - 5.2 volts, the short is in the straw hood front (SW) harness between
connector X024 pin 16 and connector X071 pin 11 wire 570 yellow. Locate the short and repair.
B. If the voltage remains high, the short circuit is in the main frame (MF) harness between connector X024
pin 16 and connector X019 pin J2-17 wire 570 yellow. Locate the short and repair.
5. Visually inspect harness and connectors for damage, bent or dislocated pins, corroded terminals or broken
wires.
A. If no damage is found, erase fault code and continue operation.
9703 1 27/05/2004
E.50.B / 7