Nige
Senior Member
No it does not. In fact it indicates that they are both within specification, and the wiring harness continuity is good.
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CAT 226B Parking Brake Indicator and Armrest Indicator Are Flashing
- Thread starter AustinC
- Start date
Got it, now I'm following. So the part that is confusing me is that when nothing is unplugged, when I measure 24 and 29 I get 17.8 ohms. I would expect to get somewhere around 73.3 ohms.
I just went out and got new measurements now that the outside temp has warmed up.
Measurements of both LH/RH solenoids and detent coil:
- Hydrostatic sol = 9.4
- Implement sol = 9.3
- Detent coil = 54.6
Total 73.3 ohms resistance.
When measuring contact 24 - 29 I get the following ohms:
- Nothing unplugged = 17.8
- Hydrostatic sol unplugged = OL.
- Implement sol unplugged = 64.4
- Detent coil unplugged = 19.1
- Implement and Detent unplugged = OL.
Should I be getting roughly 73.3 ohms here or does the detent coil get bypassed in this resistance test when both solenoids and coil are plugged in?
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Lockjz
Member
Thanks for that info,I suspected the same when i compared the pinouts on the diagram to the procedure in test step 6.
Nige
Senior Member
No you should not. When resistances are wired in parallel (e.g. the detent coil and the implement pilot solenoid coil) the total resistance of that part of the circuit is NOT the sum of the resistances that are in parallel.
The formula for total (equivalent) resistance when two or more resistors are connected in parallel is: -
See this LINKSo in your case it is 1 divided by (1/9.3 + 1/54.6). So 1/ (0.1075 + 0.0183).
This works out to 1 / 0.1258 which equals 7.95 ohms.
With everything connected you should measure 7.95 ohms + 9.4 ohms = 17.35 ohms which is not a million miles away from your measured 17.8 ohms.
Thanks Nige, you have been so helpful. It sounds like I'm passing step 6 since I'm getting OL on all other contacts.
I moved to step 7 and got OL on all contacts. Same OL results on step 8 when measuring from contact 68.
Step 8 tells me to stop here and that ECM is unlikely to have failed and to perform steps again. Any advice before I start shopping for ECMs? I've read (not sure how accurate) that technicians can't plug into the interlock ECM to read codes with a computer, only the (i believe it's called) auxiliary ecm for code diagnostics, is this true?
Nige
Senior Member
Cat ET can connect to the machine but there are no Cat Datalink connections to the Interlock ECM, only to the AUX hydraulic ECM. So I'm not sure if hooking up ET would do any good. I've never had the opportunity to try it on a machine of that vintage, only the newer ones where all the ECMs communicate via the Cat Datalink.
I hate having to condemn an ECM. They don't fail often which is why the troubleshooting procedures always state that an ECM failure is "unlikely" and to repeat all the tests again.
Thanks Nige, I'm not ready to throw in the towel yet on the ECM. The thing that I'm curious about is that I can disconnect the battery for a few hours, hook it up again and run the machine just fine until I lift the armrest and get out of the seat, that's when the lights start flashing. Shouldn't the lights flash even after the battery has been disconnected, or does the ECM need some time to register after battery disconnect?
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Nige
Senior Member
Steps 3 to 5 all state the same thing, they are simply testing a different component (each of the three coils) in each step. The procedure states
"Expected Result:
The resistance should be greater than 5000 Ohms."
You are measuring OL on each of the three steps - or infinite resistance if you will. This measurement is far in excess of the 5000 ohms minimum value from the troubleshooting procedure. Therefore your results in Step 3 to 5 should be considered as "OK".
The problem is how the text is organized on the page which could be confusing to some people. Until you mentioned it I never took much notice of the detail - all I saw is "OK - the resistance is greater than 5000 ohms." and literally blanked out the rest of the text because I had all the info I needed.
I have cut & paste the text below to show what it ought to look like in order to be more clearly understood.
If the ECM is de-powered it effectively "goes to sleep" (it has no internal battery). This takes a certain amount of time to discharge any capacitors that might be in there. I have no idea what's inside the Interlock ECM TBH, I have never seen the inside of one. Generally you would reckon that 15 minutes should be enough to put any ECM to sleep.
I think what's likely to be happening is that something inside the ECM is either heating up or suffering from vibration, so when you power it from "cold" having disconnected the battery it works fine. However when you change the state of some input into the ECM (such as the armrest switch) whatever is awry inside the ECM goes tilt and fails to work. It may even not be a failing/failed component, it might be nothing more than a soldered joint that has cracked. However it would need the services of a specialist ECM repair shop to test/diagnose/repair.
This might interest you. It could be worthwhile giving them a call, but I would suggest that you get a price for a Reman ECM, Part Number 10R8097, before you contact them so that you can compare their repair cost & warranty to that of a replacement ECM
This really clears things up for me, thank you so much. I called Cat and they want $3300 for a reman ECM, IF my core is accepted. I will call the company you shared in the video. I found this https://www.ebay.com/itm/385713741761 remanufactured ECM on eBay. What are your thoughts on going this route? Do you know if the reman ECMs are plug and play, or do they need to be calibrated to my machine?
Nige
Senior Member
On the same page there is a Reman version of the same Part Number for $1000........
I would suggest to call the company in the video and get their prices before making a decision.
There is no requirement for calibration AFAIK. Any ECM, whether new or Reman, ought to be plug & play.
As far a plug and play that is great news. I will call them now. Nige, I can't thank you enough for your help. The weight of this forum seems to be held up by your contributions.
I will follow-up on how things go. Once I find the best price (either sending mine in for rebuild or purchasing reman) before moving forward on the ECM, do you have any additional advice on what I could test/attempt beforehand?
Nige
Senior Member
Those ECMs on eBay appear to be from a company based in China. AFAIK Cat ECMs are not manufactured in that country so there is a possibility that they are clones. I wonder how they expect to get your existing ECM shipped back to them as a Reman core.?
I'll be interested to see what price ERD come up with to repair your existing ECM
I'll be interested to see what price ERD come up with to repair your existing ECM
Lockjz
Member
I found another option here and figured id share it, i think i am going with this company as the turn around time is quicker than ERD. They are out of Texas and the website says 1-2 day repair time.. The only downside for me is my housings are severely corroded and had water intrusion and they cannot replace the housing.
Module Repair Services
GoECM specializes in customer-owned module repair services for the following: Engine Control Modules (ECM) Powertrain Control Modules (PCM) Transmission Control Modules (TCM) Common Powertrain Controllers (CPC) Fuel Injection Control Modules (FICM) Integrated Power Modules (TIPM) Electronic...
goecm.com
I called ERD and their price is $1600 to repair my ECM. I ordered the ECM from eBay and the company doesn't/hasn't mentioned anything about sending my current ECM back as a core. It's going to take about 2 weeks for my new (refurbished) ECM to get here.
I have the same problem. My housing is in bad shape so I went with the refurbished one on eBay.
Nige
Senior Member
That would have been good information to share right at the start. It throws suspicion on the ECM straight away. Also you would not have received Core Credit from Cat for an ECM with a corroded housing.
Agreed, I wasn't aware of how bad it was until yesterday when I removed it. I couldn't (didn't bend down far enough) see the bottom of it when it was installed in the machine while I was testing.
On another note, the eBay seller did reach out to me asking for a picture of my serial number on the machine and a picture of the current interlock ECM. I wonder if this is so they can bench program it or if they are simply checking that I ordered the right one to avoid a return.
Nige
Senior Member
I'd be wary of giving them a photo of the whole data plate. I would supply a photo of just the last 8 characters (MJHxxxx) which is all they should need to confirm that the ECM is correct for your machine.
Good to know. Can they do some type of scam with the whole data plate?
Nige
Senior Member
Potentially. The 9th character (3) of the PIN immediately before the Serial Number (4) is referred to as a "check character" to make it harder to clone a PIN plate. Supposedly only the factory knows what it is for any specific machine.
