Hey all,

I checked the codes with my CTS, and found the P0148. I have been watching the fuel rail pressure on my CTS. At idle it is around 6-8k, and driving is around 16-17k. Truck has FASS pump installed by previous owner. Where should I start to troubleshoot this?

Thanks,
Ian

 

P0148-HIGH PRESSURE COMMON RAIL (HPCR) CHECKSUM
When Monitored: While the engine is running.
Set Condition: A deviation between the fuel pressure set point and the actual fuel pressure.

Possible causes:
OTHERS DTC’S PRESENT
FUEL LEAKS
FUEL CONTROL ACTUATOR
FUEL PRESSURE SENSOR
CASCADE OVERFLOW VALVE
CHECK VALVE DAMAGED OR BLOCKED
FUEL RETURN LINES OBSTRUCTION, DAMAGE, OR DEBRIS.
LIFT PUMP FLOW
AIR IN FUEL SYSTEM
LEAKING FUEL INJECTORS OR HIGH PRESSURE CONNECTORS
PRESSURE LIMITING VALVE
HIGH PRESSURE FUEL PUMP
INTERMITTENT CONDITION

The trouble shooting steps mainly include using the scan tool, but look for any leaks and check your low pressure side pump. It's a lot to look for... hard to troubleshoot without the right tools.

 

you can do a leak down test without the tools but it is messy and slow. the tools from miller is only about $110 try two things first. re-torque the nuts on the injector tubes if the code is still there remove the banjo bolt on the top of the pressure limiting valve and place a business card between the banjo and valve and start the engine, no fuel should come out of the valve, now make the pressure peak and again look for flow there should be none. if you are doing this by yourself place a sandwich bag over the banjo to isolate the flow.

 

I had this issue a while back and it was the #6 injector going bad. It finally had enough at the worst possible time, towing heavy on an incline with no shoulder on the road. Hope this does not happen to you and best of luck.

 

Also, I would check my battery connections, make sure the batteries are still good. I'm not saying that's what it is, but these trucks do funny stuff when the batteries take a dump. Start with the cheapest thing first!

 

Well, I also had a P0480 code, and found the FanClutch about ready to come throught the rad. I replaced that this afternoon, removed the codes, and drove home. The P0480 was gone, and magically so was the P0184. Even after 30min of driving, it never came back. I was thinking that I also swapped in my new batteries from my old truck when I bought this one. And who knows how long that code had been there. The previous owner told me he installed a reman CP3 and new injectors about 6 months ago, but didnt have any reciepts. I did notice today when the shroud was off I could see the CP3 was replaced. I also found my front oil leak. When he did the CP3 he cracked the plastic cover. I repaired it, adn ordered a new one. Anyways, long story short, the code is gone, and until it comes back, im going to pretend, I never saw it.

Thanks to everyone for the great information and replies.

Ian

 

Glad it worked out for you, man.