Cat 259D wiring schematic?

[Matthew26287]

I need a wiring schematic for a 2017 Cat 259D FTL08734. If anyone has one laying around I’d appreciate it!

 

[Matthew26287]

I need a wiring schematic for a 2017 Cat 259D FTL08734. If anyone has one laying around I’d appreciate it!

The reason I’m looking is I’m having problems with my coolant temp. The advanced display constantly reads 140°. Not sure if anybody has any insight into this? I’ve attached pictures I have 1 active event.

 

[heymccall]

Attached schematic. Middle of 3 serial number series.

 

[Nige]

Have you tried resetting the display.?

 

[Matthew26287]

Attached schematic. Middle of 3 serial number series.

Thank you I appreciate it!

 

[Chrisso]

Horrible sensor to get to.



Need to check voltage across those wires with the sensor plugged in somehow. Signal wire voltage should vary between .1 and 4.9 volts or close to it. Start and warm engine. If the voltage doesn't change well that explains what the display is showing (sensor or eng harness issue). If it does change you most likely have a data link or display issue.

For what it's worth try resetting your display as Nige suggested first. Takes 5-10 seconds. Literally press and hold the far left and the far right button on the display for 5 or 10 seconds.

 

[Matthew26287]

I’ve tried resetting the display with no change. I did check voltage at the plug it said 5v. I’m not sure about checking voltage with the sensor plugged into the actual plug. I’m still curious as to why it doesn’t throw a code when unplugged. There is no changes. Even with a scanner hooked up still reads 140° from engine ECM.

 

[Nige]

I’m not sure about checking voltage with the sensor plugged into the actual plug.

You need what’s known as a set of “spoons” to attach to the ends of your meter leads. They are curved to the profile of the cable and can be slid along the wire inside a connector to make contact with the metal pins inside it.

See this link. Other options are available.

Electronic Specialties 616 Spoon Probe Backprober | eBay

Electronic Specialties. Compatible with 4mm banana plug test leads, like ES 142-1 for example. About JB Tools. Eklind 10007 L Key Set, 7pc. EZ Red BK550 Super Gripper Battery Lifter. FJC 6916 7 CFM Vacuum Pump.

www.ebay.com

 

[Matthew26287]

You need what’s known as a set of “spoons” to attach to the ends of your meter leads. They are curved to the profile of the cable and can be slid along the wire inside a connector to make contact with the metal pins inside it.

See this link. Other options are available.

Electronic Specialties 616 Spoon Probe Backprober | eBay

Electronic Specialties. Compatible with 4mm banana plug test leads, like ES 142-1 for example. About JB Tools. Eklind 10007 L Key Set, 7pc. EZ Red BK550 Super Gripper Battery Lifter. FJC 6916 7 CFM Vacuum Pump.

www.ebay.com

Thank you I’ll get ahold of some and report back with what I find out!

 

[Chrisso]

I’m still curious as to why it doesn’t throw a code when unplugged.

So am I. It should also throw another code when you jumper the two wires. Below .1 volts and above 4.9 volts on the signal wire are supposed to be the trip points.

Spoons are great but I'm not sure you'll be able to get them in there in that location. You might. Just do what you need to do and re-insulate the wires afterwards, not ideal but there's a right way and a wrong way to do it. Spoons will definitely work on the ECM end of those wires (EDIT: no they won't, ECM is Kubota).

 

[Matthew26287]

So am I. It should also throw another code when you jumper the two wires. Below .1 volts and above 4.9 volts on the signal wire are supposed to be the trip points.

Spoons are great but I'm not sure you'll be able to get them in there in that location. You might. Just do what you need to do and re-insulate the wires afterwards, not ideal but there's a right way and a wrong way to do it. Spoons will definitely work on the ECM end of those wires (EDIT: no they won't, ECM is Kubota).

I may be able to hook my scanner up and get readings possibly. I’ll have to check to make sure. That’s why I’m kinda worried it’s not throwing codes. I’m thinking it might be something in the Engine ECM.

 

[Chrisso]

My money’s on the sensor. But who knows, that’s why we troubleshoot.

I’d prioritise getting voltage readings from the circuit before anything else.

 

[Matthew26287]

My money’s on the sensor. But who knows, that’s why we troubleshoot.

I’d prioritise getting voltage readings from the circuit before anything else.

Alright I can do that I’ll get back with you! I appreciate the help!

 

[Nige]

Might be a silly question but are you doing your measurements on the correct sensor.?

 

[Matthew26287]

Might be a silly question but are you doing your measurements on the correct sensor.?

View attachment 309349

I’m almost certain it’s the right sensor it’s definitely a stretch to reach back too it.

 

[Nige]

I’m almost certain it’s the right sensor it’s definitely a stretch to reach back too it.

My question stems from the fact that the sensor does not throw a Code whether it is connected or disconnected. You should double-check by confirming the wire colours/numbers (406 Purple & 221 Black) on the machine side of the sensor harness connector.

 

[Matthew26287]

My question stems from the fact that the sensor does not throw a Code whether it is connected or disconnected. You should double-check by confirming the wire colours/numbers (406 Purple & 221 Black) on the machine side of the sensor harness connector.

I double checked. It is the correct wiring in looking at.

 

[Matthew26287]

Could it possibly be in the machine control module?

 

[Nige]

Could it possibly be in the machine control module?

Could be the Engine ECM, could be the Display module. Worst case scenario it could be both. Flip a coin, do you feel lucky.?

 

[Matthew26287]

Could be the Engine ECM, could be the Display module. Worst case scenario it could be both. Flip a coin, do you feel lucky.?

Well like I said with a scanner hooked up reading from ecm it always says 140° from live feed also so probably leaning more towards ecm.