Discussion:
Caterpillar EP KT series code 33

I have an EP16KT s/n ETB4B01613 that has a code 33. Conditions: key on, seat switch closed, left and right drive function normally. Steering pump motor functions normally. If any hydraulic lever is actuated, line contactor will open and a code 33 is set. I removed one cable from hyd motor to simulate open motor circuit and when hyd lever was actuated still set code 33. I pulled head cap and buss assembly and took T1P and D1P out of circuit. I tested both and both tested bad. I also tested pump motor for short to case and resistance as compared to a known good motor. No short and resistance for both motors was around.07. (out of circuit) on my DMM. I installed new t1p transistor and d1p diode. Drive and sreering still functioning normally. Still sets code 33 if any hyd lever is actuated. I once again pulled motor cable
And actuated hyd lever. It set code 49 that time which i think is p motor open circuit. I pulled G and E wires off of new t1p and code 33 is set as soon as key switch is turned on. I did visual inspection and smell test of driver board no obvious damage and no burned smell. Ihave verified wiring continuity from t1p to driver board. I disconected cs3 conector and turned on key it set another code but not a 33. I don't remember the code. Battery voltage is good. And display indicates full charge. 36V lift by the way.
Where do I go from here?
  • Posted 28 Jul 2012 09:07
  • By SRStech
  • joined 28 Jul'12 - 1 message
  • Tennessee, United States
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Please tell us what you found
  • Posted 27 Feb 2017 00:42
  • By troy_m
  • joined 13 Sep'08 - 112 messages
  • Ontario, Canada
A-Lift Services -- safe -reliable -affordable
well your on the right track
code 33 is defective transistor drive
and code 49 indicates pump motor wire breakage according to the troubleshooting guide.

code33 possible causes:
1) wire break in T1P
2) faulty drive board
3) faulty CS3 current sensor
4) faulty logic card
5) faulty wiring

code 49 possible causes: basically the same
1) wire breakage in pump motor
2) faulty CS3 current sensor
3) faulty logic card

i'd recheck the power cables
recheck the sensor wires
check all harness plug pins and make sure they are inserted completely in thier respective sockets

try the wiggle test to see if you get any variation in vom readings while checking, you might also want to do a volt drop check on those wires and cables, not a continuity check.
if they are corroded or have bad crimps on the terminals this can cause problems like this.
  • Posted 3 Aug 2012 22:20
  • Modified 3 Aug 2012 22:25 by poster
  • By swoop223
  • joined 23 Mar'12 - 3,691 messages
  • North Carolina, United States
You've been swooped!
swoop223@gmail.com

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