287
M4.8-1055-077
03 Rev. 10/09
ELECTRICAL
Event Code 740
Event Code 740
Accessory Potentiometer POT3 Outside Calibrated
Range.
The POT3 input value is out of range from the cali-
brated values.
Note: ECR4 and POT3 share power supply from
ACCESS 2.
Note: If code is intermittent, then recalibrate POT3
(C1.3 calibration menu) thumb ball held firmly against
stops.
Step 1: Use Analyzer menu A2.2.7 in display to verify
input while actuating accessory hydraulic function.
• If: Value is not between 2 and 11 Vdc or inconsis-
tent with commands.
– Then proceed to Step 2.
• If: Value is consistent with command and within
range.
– Then replace ACCESS 2.
Step 2: Verify mechanical operation of POT3.
• If: Mechanical issue.
– Then repair and recalibrate POT3.
• If: POT3 mechanical operation is correct.
– Then recalibrate POT3 accessory potentiome-
ter. If issue remains, then proceed to Step 3.
Step 3: Check power supply voltage to POT3 between
CA220-7 (+) and CA220-9 (-). Should be approxi-
mately 12 Vdc.
• If: Power supply voltage correct.
– Then proceed to Step 4.
• If: Power supply voltage incorrect.
– Then proceed to Step 5.
Step 4: Check wiper circuit input at ACCESS 2. Con-
nect leads to CA410-12(+) to CA220-8 (-) and check
continuity.
• If: No continuity.
– Then repair wiring.
• If: Wiring has continuity.
– Then replace POT3.
Step 5: Check voltage across pins CA408-1 and
CA408-3 (AC) or CA405-15 and CA405-16 (DC).
• If: Approximately 12 Vdc.
– Then repair/replace wiring or connection be-
tween CA220 and CA405 (DC) or CA408 (AC).
• If: Not approximately 12 Vdc.
– Then replace ACCESS 2.
Figure 16090-01
Crown 2007 PF15665-77 Rev. 10/09
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