Tony Wells
Senior Member
Nige, that sounds like a good idea and it may come to that. We've been advised to try connecting an instrument to the cam position sensor and checking it for a consistent signal. Birken, I plan on bringing in a scope, but it's not storage capable. This is one time I wish I had a small, toughened DSO, but my electronics lab in my shop is more intended for bench work. I have 3 scopes, but more suited to that type of work, since one of my hobbies is restoring antique radios and boat anchors. Maybe it's time to invest in a DSO. Nahh, I'm trying to retire, not dig in deeper. Seems to me it would be simpler to just replace the sensor, but I'd really want to know there was a problem before spending the money and time to do it. But honestly, I'm not looking forward to bringing one of my lab scopes to the field. Plus I have no idea what waveform I should be seeing in the first place, so that will be just guesswork and hoping to spot some sort of anomaly. Another suggestion, already acted upon by the owner unless I misunderstood, was to buy a rebuilt ECU and swap it out and send the original out for testing/reconditioning. I'm not sold on the wisdom of that, exactly, but apparently the cost is acceptable and we will have a backup on hand should we ever need it. I believe it may arrive tomorrow. It seems that even though we have several grinders, those we have that are running aren't keeping up. We have contractual obligations for specific delivery of chipped goods at a wholesale level and cannot afford another one to go down right now, so we are going to push a little on the Hogzilla, and another one or two that are out of service for various reasons, primarily with the grinding mechanism and fairly easy to repair, just time consuming and our main fab guy is buried with work at the moment. I shouldn't be doing that type of work, given my health so probably won't be fabricating new parts for any of those. /begin extraneous commentary I say that, but I'm working on reconditioning a dogbone for a Doosan wheeled loader that was very neglected with the grease gun and had the pin eat through the hardened sleeve, into the boss and now I have a rather large egged hole in one end. I'll have to cut out the old boss, bore the plate oversize and build a new, custom boss with a stock ID to receive new sleeves. Then of course, I'll find the bucket holes are bad with the pin fit very loose, and have to get it welded up and line bored, or make new ears and weld them on. But that's another story. And there are more...it never ends. Never a dull moment around here, to be sure. /end extraneous commentary
We cleared all the codes stored in the ECU, and after a short run, only about 15 minutes, none returned. But there is a persistent hard code we can't clear that I don't quite understand. I need a little education. Per Cat, there is no throttle position sensor on the engine. But the ECU is apparently looking for a signal from it. So of course it sets a code on it. Ill be the first to admit I'm not an expert on these engines, so I would like to know what system Cat is using to replace what would normally be the tps to determine engine load. The systems I am familiar with use the tps signal in comparison to a air flow sensor to accomplish this and respond to a load lowering the engine speed by increasing the injector pulse width (condensed, more or less). How does Cat handle this function?
Just to add a little spice to this, these are the codes that were set during the previous test run. I was not present so can offer nothing as far as actions of the people running it during the test session:
Fault Code CDL: Starter motor relay
Fault Code CDL: 168 Electrical system voltage
Fault Code CDL: 91 Throttle position sensor
Fault Code CDL: 546 Ether injection current limit relay
Fault Code CDL: 4 Cylinder 4 injector
As I said, after clearing all, the only recurring code is the "ghost code" 91. Since Cat built this engine, and I don't believe it was ever field flashed, I don't understand why the ECU is even looking for the TPS signal.
We cleared all the codes stored in the ECU, and after a short run, only about 15 minutes, none returned. But there is a persistent hard code we can't clear that I don't quite understand. I need a little education. Per Cat, there is no throttle position sensor on the engine. But the ECU is apparently looking for a signal from it. So of course it sets a code on it. Ill be the first to admit I'm not an expert on these engines, so I would like to know what system Cat is using to replace what would normally be the tps to determine engine load. The systems I am familiar with use the tps signal in comparison to a air flow sensor to accomplish this and respond to a load lowering the engine speed by increasing the injector pulse width (condensed, more or less). How does Cat handle this function?
Just to add a little spice to this, these are the codes that were set during the previous test run. I was not present so can offer nothing as far as actions of the people running it during the test session:
Fault Code CDL: Starter motor relay
Fault Code CDL: 168 Electrical system voltage
Fault Code CDL: 91 Throttle position sensor
Fault Code CDL: 546 Ether injection current limit relay
Fault Code CDL: 4 Cylinder 4 injector
As I said, after clearing all, the only recurring code is the "ghost code" 91. Since Cat built this engine, and I don't believe it was ever field flashed, I don't understand why the ECU is even looking for the TPS signal.
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