TriPac APU Alarm Codes

I have a code 47 on the tri pac. Code says low back pressure. What should i look for?

 

Any of you ever have the code bat on display? I get it occasionally and I can't figure it out.

 

Do you have the digital display? I have a digital display and have never seen that code

 

If you have an Evolution model with a DPF, you either have a sensor issue (soot build up os common) or a problem with the DPF itself.

 

The bat code means you have low battery voltage. So you either need batteries, or you have a corroded or bad connection.

 

How do you properly bleed air from TK apu coolant? I have lines going to truck

 

Do you have a petcock in a port on the water pump?

 

Yes on top of water pump

 

Let the apu run for a couple minutes then open the petcock. If it has a hose attached catch the coolant in a bottle. Just looking for a clear stream of coolant.

 

Copy that.
If batteries prove to be good, I'd start checking for corroded wires at the alternator. Most of my electrcal issues were there.

 

It's quite unlikely that you have only one hose hooked up to the engines cooling system. You should have two with a petcock on each.
Make sure coolant level is full and both petcocks are open. Run truck engine until the thermostat opens. This primes the whole cooling system including APU. Best would be if you could get the engine temps up till van kicks in. It might be difficult in the winter time.
Shut down A/c while truck engine is running. This cycles the engine van and might fool you.