1996 Cat 315L throttle dial not working

[ToxicTrav117]

The machine runs well on the backup throttle system, the only problem is the dial doesn't work and it's annoying flicking the backup switches. Does anyone have any ideas what could be wrong with it? When I turn the dial, the speed number on the display works but it doesn't do anything throttle wise. I'm thinking there must be something wrong with the throttle assembly or something but it confuses me as I am not sure how the backup one would work if that's the case.

S/N: 6YM01670

 

[ToxicTrav117]

I think I found the problem because there was a bunch of mice nesting and stuff in the inside of the right console. Wires were chewed on both the ignition and throttle switch assembly. I'll have to pull it apart and inspect the wires all the way back to the harness as I will definitely have to replace them.

 

[Nige]

If you want a copy of the electrical schematic to help identify wires post a Serial Number.

 

[ToxicTrav117]

Ok, I have not figured out the problem. The throttle dial does work but it is very hesitant and not always accurate to the throttle number as sometimes it will rev up and then down to the correct number. The backup throttle switch works great. I investigated and both the dial throttle and backup throttle work off of the same motor and I do not believe that is what the problem is. There is no error led light on the pump controller so I don't believe its a problem with the computer. I replaced the throttle switch thinking maybe it was shorted out from the mice chewing the wires on it but that did not change anything. Any ideas?

 

[anuradha]

Hello,

According to your explanation i think there may be a wiring problem, if the wiring is ok then the problem will be the controller.

If you know how to access in to machine data mode, check whether there is a real time error code when machine is running.According to your problem if i am correct there will be E 31 error code.

If it is showing we have to troubleshoot it according to that.if you like put your e mail address then i can send some infos that might be useful to you.

 

[ToxicTrav117]

I get a error code E11 on the monitor but I don't know what that means.

 

[anuradha]

Hi,

E 11 means - governor actuator feedback sensor is shorted to body ground.

 

[ToxicTrav117]

Where should I begin to look for fixing that?

 

[JPV]

I don't know about the feedback sensor but we had to replace the whole actuator assembly on our 325L because the cables seized up. I couldn't get parts for it, only the whole unit and it was expensive. If I recall it was around 1200 bucks. I also remember when I took it apart I wasn't sure if I could get it put back together properly because of the way everything was timed, I don't remember the details on it though. So pay attention if you pop it apart for a look!

 

[ToxicTrav117]

Well the cables work fine on mine because both the backup and automatic switch work. The only problem is the automatic throttle dial does not work consistently almost like there is a short somewhere like the computer is telling me.

 

[JPV]

I suspect the shorted feedback sensor is in the actuator assembly, I don't know if there is a procedure for checking it. A wiring diagram might help. I believe that is a stepper motor that moves the throttle cable a certain amount depending on the dial setting. The feedback sensor would tell it where to stop I am thinking and is probably part of the unit. Someone with access to SIS might be able to help, I wouldn't be able to look it up for a few days.

 

[Nige]

You need to get hold of a copy of Cat publication SENR6155. That's the troubleshooting/operation manual for the engine & pump control system.

Meantime here is the diagnostic procedure for E11. I'll send you an electrical schematic. Something tells me you're going to need it.

E11 - Governor Feedback Sensor Circuit Is Shorted To Body Ground
This error code is present when the controller senses that the governor feedback sensor circuit is shorted to ground. The possible causes of this fault are:
a. Signal circuit in the machine harness is shorted to ground.
b. Sensor is faulty.
c. Controller is faulty.
NOTE: Ensure error code E11 is being shown on the monitor display.
1. CHECK SENSOR - Disconnect the machine harness from the sensor. Check the monitor for error code E11.
* The error code E11 is no longer shown on the monitor display; the circuit is operating correctly. The sensor is faulty. Check or replace the sensor.
* The error code E11 continues to be shown on the monitor display; the machine harness is shorted to ground or the controller is faulty. Go to Step 2.
2. CHECK HARNESS - The sensor remains disconnected from the machine harness. Turn the disconnect and key start switch to the OFF position. Disconnect the machine harness 24 contact connector from the controller. At the machine harness connector for the controller, measure the resistance between contact 21 and frame ground.
* Resistance is greater than 5000 Ohms; harness circuit resistance is correct. The controller is faulty. Replace the controller; see Controller Replacement.
* Resistance is less than 5000 Ohms; the machine harness is faulty. There is a short between frame ground and the sensor signal circuit in the machine harness. Repair or replace the machine harness.

 

[ToxicTrav117]

Where is the governer feedback sensor? Or is it the whole governer actuator assembly that I should unplug?

 

[ToxicTrav117]

I unplugged the governer cable control and the E11 code still showed on the monitor.

 

[ToxicTrav117]

Image

 

[Nige]

Take a look in Grid C-7 on page 2 of the schematic that I sent you. The sensor is part of the governor actuator - inside the red area.
The signal wire is A761 Purple.
When the diagnostic says "Disconnect the machine harness from the sensor", unplug connector (CONN) 44.

 

[ToxicTrav117]

I believe that is the diagram of the connector I unplugged that goes to the governer actuator. So if the code still persists does that mean there is a short in the wire in the harness?

 

[Nige]

I believe that is the diagram of the connector I unplugged that goes to the governer actuator. So if the code still persists does that mean there is a short in the wire in the harness?

As per procedure above - * The error code E11 continues to be shown on the monitor display; the machine harness is shorted to ground or the controller is faulty. Go to Step 2.

 

[ToxicTrav117]

Hmm I'll have to look more at all the harnesses. I cleaned up the ground connections underneath the cab but that didn't change anything. I've also been having weird radio issues so maybe it has something to do with inside the cab where I'll have to pull out the storage box and inspect the wires behind the heater vents in the cab.

 

[Nige]

It only needs one test to determine if it's a bad harness or the controller - Grid A-7 on Page 2. Wire A761 Purple is the same signal wire from the feedback sensor that is in CONN 44 at the other end of the harness.



"CHECK HARNESS - The sensor remains disconnected from the machine harness. Turn the disconnect and key start switch to the OFF position. Disconnect the machine harness 24 contact connector (CONN 2) from the controller. At the machine harness connector for the controller, measure the resistance between contact 21 and machine frame ground.
* Resistance is greater than 5000 Ohms; harness circuit resistance is correct. The controller is faulty. Replace the controller; see Controller Replacement.
* Resistance is less than 5000 Ohms; the machine harness is faulty. There is a short between frame ground and the sensor signal circuit in the machine harness. Repair or replace the machine harness."