I have a 2006 Cat 246C S/N JAY01423 that is reporting this code. I found troubleshooting steps, and just want to confirm what I think the problem is: Step 1) Check Duty Cycle of sensor signal on ECM contact J2-25 and J1-45 When I did this test, the meter reported duty cycle of 0 at rest and when I moved the roller button to both extremes (no response). However, when I moved the joystick forward, back, right, and left I did see duty cycle reported by the meter (also the numbers were sporadic). Forward, right, and left would occasionally report 501.5 Hz, back was around 5-70 Hz. It was, however, quite sporadic in the reported numbers. No other controls appeared to report duty cycle change on the meter. Step 2) Check the voltage at the sensor Measure voltage at machine connector for harness, contact 1 and 2. For this test, my meter reported 8.14V (acceptable). Step 3) Check for an open in the signal circuit Measure voltage at machine connector for harness, contact 2 and 3. For this test, my meter reported 5.02V (acceptable). Step 4) Check the signal circuit for a short Connect meter lead to J2-25, then test each other contact in J1 and J2 for a short. No short detected (acceptable). Step 5) Check and clean all connections, re-check diagnostic code Completed this step, then started machine and confirmed that it is still reporting 2204-3 diagnostic code. The results of step 1 seemed very bizarre, any idea why I would see this behaviour?
In the first step, your thumbwheel roller did not show the required readings, but should have been in the neutral position, the duty cycle should be approximately 50%. But when you started moving the joystick itself, the readings began to appear, which is very similar to the fact that you have an intermittent fault somewhere in the thumbwheel roller wire, or in the thumbwheel roller itself. Try replacing it. But first, check the wire for fraying.
Thanks, I will remove the joystick and see if I can find anything wrong with the wiring/thumbwheel.
You should hope to find a wiring fault because if the thumbwheel switch is faulty it is only available as part of a replacement joystick handle that costs $500+.
Let's make something clear right now. Duty cycle is measured in %, not Hz. You are not trying to measure a frequency change in output from the sensor. The first thing I suggest is that you check to make sure your meter is actually capable of measuring duty cycle. On most meters if you press the Hz button once you'll see the Hz icon appear on the screen. If the meter has duty cycle capability then if you press the Hz button a second time the icon on the screen will change from Hz to %. Try repeating Step 1 in the troubleshooting procedure by back-probing Pins 2 & 3 of the 4-pin connector located directly under the joystick for the duty cycle output from the thumbwheel roller sensor and report your findings.
I will try this test, I did have my meter on Hz, not %. Checking in the cab will be a lot easier than crawling under it to check at the ECM. Thanks.
I usually suggest first to check the signal at the output from the joystick by back-probing the 4-pin connector then if it's good there go and check at the input to the ECM.
Thanks Nige and Deimos for the help, I found the problem. The wiring between the connector and the joystick handle had been repaired at some point, and it appears that during the repairs 4 of the wires had been crimped too tight or bent and ended up breaking. I replaced that section of wiring, and all appears to be working well now. I appreciate all of the support that you guys provide!