Good Morning! My Cat 299D has thrown a 638-8 Error Code - Engine position Sensor - Abnormal Frequency - Pulse Width or Period The machine will not move. Just replaced a Turbo on the engine and probably put 6 hours on the machine before throwing the code. Would it be a lose connection on the plug - If so, where would this sensor be located? Any advice what to do to resolve the issue? Thanks!
I believe my engine is a Cat C3.8 engine / Kubota V3800-CR engine
Having difficulty finding a troubleshooting procedure. Can you supply a machine Serial Number.? Also I can find a number of 638-X Diagnostic Codes but not 638-8. Can you post a photo of the message that shows on the RH panel please.
Nige, Thanks for your response. Cat Serial & Model # is listed below along with screnn shoot of on board computer with Error. Thanks! Model - 2018 Cat 299D2 XHP SERIAL NUMBER: DX203342
Ha......! So the Active Diagnostic Code that you have is 636-8 not 638-8. That makes a big difference. Attached the procedure for testing the speed/timing signal. While you are messing around with the wiring, and seeing as you also replaced a turbo, I also suggest to check the security & cleanliness of the engine-block-to-chassis ground cable. You'll probably find the engine end of it somewhere around the starter motor. If you want a complete electrical schematic please ask for one.
Thanks for the information- I'll check into this later this week and will report what I find. Thanks again!
Nigel Yesterday, we cleaned the engine-block-to-chassis ground cable, however it did not make a difference. We also pulled the sensor (shown in picture #3) to see if there may be any metal shavings from the turbo. Did not see any, but did not rotate gear. Also not sure this is the correct sensor? After the engine is shut off for more than 5 minutes, the codes clear and you can move the machine for about 3-4 minutes, and then it throws the codes shown below, shutting machine down, so that it will no move. The (2) codes, being thrown are as follows 636-2 Engine Position Sensor - Data Erratic, Intermittent or Incorrect 636-8 - Engine Position Sensor - Abnormal Frequency Pulse Width or Period I was thinking that it may be as easy as replacing a sensor, but could it be something with the new turbo that we installed. The turbo shaft that holds the impeller on the exhaust side of the turbo failed (Broken) however all parts where intact and where removed. After the new turbo was installed, we changed all fluids and filters including oil and hydraulic oil. The machine ran fine for about 15 ours after new turbo was installed, however that last few hours, it sounded like the hydraulic pump was cavitating. There was a leak on a grapple hose, and so we topped of the hydraulic oil and to my surprise it was full and we over filled the fluid to the top. Still not sure what the cavitating noise is from. It only does it once in a while? the last thing I would like to mention, is that fuel filter looks empty? We replaced the filter when turbo was changed. I assume the fuel filter should be full? That may be another issue, however we are not throwing any codes, nor does the machine act like it is starving for fuel.
I'm not usually one to advocate for taking short-cuts where troubleshooting is concerned, but, look in the indicated area below. You should find the harness zip tied to a ladder clip bolted to the chassis. Look for harness damage in this area. It MAY save you some time. Good luck.
Both the procedure I posted above and the schematic I sent to you will have wire colours and numbers on them. It’s easy to identify any particular sensor by the wire numbers and colours on the machine harness side of the sensor connector. EDIT: See attachment. The crankshaft and camshaft speed sensors are identical. Try swapping them and see if the Diagnostic Codes change from a 636 Component Code to a 723.
See this Link . Same problem of an empty fuel filter also on a 299D. Pay particular attention to Post #16. There is a screen installed directly before the electric fuel priming pump. 416-5884 is the Part Number. Have you checked or changed that.?
Did you check, and if so what were the results of: 1. Security of the CAN resistor. 2. Resistance measurement of the CAN resistor. 3. Supply voltage to the sensor. Those are the first 3 steps in the diagnostic procedure attached earlier.
Thanks for the advice. I will attempt to do everything listed in above post. It may be Monday until I can take the time to do this Can someone provide me a complete electrical schematic. Nigel mentioned he had one in the above post. Thanks again.
I sent it to you yesterday. Check your messages (envelope icon at the top right side of the screen).
Nige, I'm not seeing the attachment that show the wire colours and numbers on them. Can you send that to ma again. Also I'm having a difficult time locating the CAN resistor. Thanks
Nigel, I see the attachment, thanks for sending this to my inbox.
Sorry forgot the attachment from the Parts Manual showing the location of the engine sensors.
1) Found a blown fuse on the fuel pump. replaced the 15 amp with a 20 amp. Started it up again and it blew the 20 amp also. (I assume that the pump is bad) Not: When we installed the turbo, we also replaced the fuel filter and the filter for the lift pump (but did not change out the lift pump). (See pictures #2,3,4) 2) We also just Changed out the The crankshaft and camshaft speed sensors (Swapped them), but since the fuel pump fuel is blown, I did not move the machine. (See Picture #1) It did throw a 636-8 - Engine Position Sensor - Abnormal Frequency Pulse Width or Period after we swapped them out. Thanks again!
To me that suggests a wiring problem. First step is to closely inspect the engine wiring harness for damage in the specific location identified by @Cmark a few posts above. After that get into the Speed/Timing signal test posted way back up above somewhere.
Ok, Thanks. I'll look into this on Monday and report back.
Just order this fuel pump to replace the original Cat Pump. I assume the pump is causing my fuse to Blow? 12V Fuel Pump w/Filter Set 416-5886 416-5884 for Caterpillar $76 on Ebay
Those electric pumps Cat uses are absolute dog####. They never seemed to last very long. If you unplug the pump and the fuse doesn't blow then its usually the pump.
A thought. Did you actually run the engine after swapping the crank/cam sensors.? Some sensors (e.g. track motor speed) require a genuine signal for X amount of time from the replacement sensor before the Code will go from Active to Logged. I'm not sure if the engine speed sensors are the same.
Nige, We swapped them and then started the engine up, however I heard the fuse blow and turned the key off. The engine probably ran 30 seconds and then the code game up. I ran the engine for about 1-2 minutes. I did not move the skidsteer forward, or run the RPMs up. I probably should have done more testing on the pump, but just went ahead and ordered a new one. When we changed the turbo, several weeks ago, we noticed the fuse was blown for the fuel pump and changed it. Just thought it may have been a short from power washing the engine. Not sure how long the fuse has been blown, after the turbo installed. We did run the machine maybe 12-16 hours without any issues until it stated throwing the code for the Engine Position Sensor. Before we knew the fuse was blown, for fuel pump. We where able to limp the skidsteer back to the shop (with the error 636-8 Error code. The machine would run, but when it threw the code, the parking brake would come on and you could not move the machine.We would shut the machine off for about 10 minutes - start it back up and the machine would run and we would move it about 50 yards until it shut down again. We did this about 4-5 times, before we got it back to our work shop on site. Now I'm wondering if the machine shut down because of the fuel pump or if it was because of the engine sensor error code. Note: we never received an error code on the fuel pump. Thanks again for everyones advice on the forum!
Sometimes the machine will run just fine without that electric pump so long as the fuel system was bled and primed. Where you're truely screwed is when you change fuel filters.
After replacing the fuel pump. (Fuse kept blowing). The code cleared and I'm back up and running. I have ran it 4-5 hours. I'm thinking the short in the fuel pump may have caused the issue. 1) could it been starving the engine, causing the engine to not run properly and then throwing the code? 2) could the short in the pump, cause some electrical issue, causing it ti throw a code? Hopefully that is the issue. Now I have a hydraulic issue. The pump had a small cavitating sound, before the code issue, however when I checked and filled the hydraulic tank it was full. I'll start a new thread on this issue. Thanks!