Cat code Question

Intake actuator on cylinder #5 or #6. You need to get it hooked up to a computer to narrow it down further. A low current code could be an actuator or wiring. If it's a not responding code, it could be an actuator, adjustment, or a cracked housing. Cracked actuator housings are fairly common at the end bolt holes. Injector harness's are also pretty common.

The best you can do without a computer is to pop off the rear valve cover and take a look. Many times with the housing cracks, the actuator screws break too, so if any are broke off or loose, it's a sign that the housing is cracked. Make sure all the rocker studs are tight, they were known to break too (there are updated studs now). Look very close at the front and rear stud holes of the actuator housing, that's where the typically crack. Check the electrical connections.

If everything visually looks good under there, you need to get it hooked up to Cat ET to figure out what's wrong.

If this is your 1st Acert, I'll give you some advice. How many miles are on it and do you know the maintenance history?

1. Injector harness's were known to fail. Depending on the miles, you may want to just change them.
2. Rocker studs were breaking. Cat came out with a better stud, but it was not a recall, just replace as fail. Get the updated studs installed before one breaks and does serious damage.
3. There is an updated kit for the compressor inlet to stop the rubber hose from blowing and in some cases, the steel pipe was puling the threads out of the compressor head. The new style is 2 fittings and a braided hose. If you have a steel pipe with a short rubber hose, replace it with the new style.
4. Intake Actuation Pressure Sensors fail and give flash code 95. It's common enough to buy one to throw in your glove compartment. It's an easy swap, they are on the pass side front of the motor by the T-stat housing. 99% of the time, flash code 95 is that sensor, so it pays to have one to swap out to see if that fixes it before you pay a shop.
5. There is a pre-cooler diverter valve on the right side just under the turbo. They are fairly trouble free, but the wires are routed behind and under the exhaust manifold. Heat makes them brittle and the wires can short out or break (this gives a flash code 98. There is enough slack to pull that harness leg out and route it around the outside away from the manifold.
6. There are 2 preformed hoses for the pre-cooler. 1 is easy to see under the turbo, the other is very hard to see. Make sure that you check them closely on PM's, it doesn't hurt to carry spares as most road services wont have them on the truck.
7. On PM's, check that the manifold and turbo nuts are tight, they blow gaskets if left loose. On the manifold you have 1 short stud, this is the 1st one to come loose and it pays to put a wrench on it to check every PM. I found a few broken exhaust studs, just like any other cat.

 

Keep in mind the updated studs are not designed for strength but have a groove cut so when they break again they are broken above the head and you don't have to drill them out. I would replace them all with the updated ones if that is your problem just because I have had the unfortunate experience of getting the broken studs out.

 

That code can cause low power, but I have never seen any further damage from it. If it's running OK and intermittent, I'd feel comfortable driving back to Pheonix to your regular trusted shop.

Once the upadates are done, the C15 Acert is not a bad engine as far as emission engines go. The intake actuators are problematic, but nothing like EGR problems on other engines of that era. I'd take the Acert over other engines of those years.

 

What is a code 31 & 36 on a 2002 t800 c15?

 

31 is loss of vehicle speed signal I believe. Maybe the 36 is speed sensor don't hold me to it. I would check that first.

 

31 is vehicle speed loss of signal. 36 is vehicle speed signal invalid, out of range or rate of change. Make sure that the trans yoke is tight.

 

Checked it yesterday its got up and down play. That explains the loss of power when I take off in 1st and 2nd gear. It'll only rev up to 14-1500 and then be flat till I quick shift to 3rd then its fine.
Thanks GrapeApe

 

A vehicle speed sensor problem can kick the ECM into anti-tamper mode, which limits RPM. So that makes sense. The speedo would probably drop too when it happens, but sometimes you wont notice with the distraction of a problem.

Anyway, if the yoke is loose, the VSS tone ring can spin and casu your problem, so tightening that is the first and hopefully the only step to fixing your problem.