When I display current DTC's, I only see one:
DTC U1000 ---H--CS
When I display all DTC's, I get the following list:
ABS C0040 M-PH---S
PCM P0101 ---HX--S
TCCM(/ABS U1000
PCM P0700 ---HX--S
DIC U1000 ---H--CS
TCCM(/ABS C0550 ---
TCCM(/ABS B0790 ---
TCCM(/ABS B2725 ---
The current tune is attached.
Attachment 10160
I see a P0700 code, but no trans codes. Also I see a U1000 which sounds like your reduced power may be a communications issue with the TCM or TCCM. There is a bulletin out for the C0550 code which involves a flash update for teh TCCM due to it not waking up when the key is turned on. If the ECM doesn't see teh transfer case module, it could cause a reduced engine power situation. Also the P0101 is a MAF performance code which is fairly common on tuned trucks(I turned mine off as I didn't feel like rescaling the MAF to get rid of it).
This evening I removed and inspected each boost tube sleeve, cleaned up the connections, and reinstalled each one. I took it for a drive and verified that the problem still wasn't fixed. After that, to rule out the possibility of a bad wastegate actuator, I used vice grips and a scrap piece of rubber hose to temporarily crimp the boost line leading to the wastegate actuator. I took it for a drive again after doing this, and it's still the same. Most of the time, I only get 2-4 psi boost, but on occasion, something changes and I'll build up to 12-14 psi boost.
I was lucky enough to be able to catch one of those on a data log, so I'm hoping that information might be useful. In the log file, at frame 268, something changed and the boost started building. It built up to 12-13 psi and held it, so it's leading me to think that a boost leak isn't the problem. Like THEFERMANATOR noted above, I'm getting a P0101 MAF sensor performance code. Could an incorrect MAF sensor reading be limiting fuel, and do the MAF sensor values in the attached log appear normal (especially those prior to frame 268)?
P0101 "Mass Air Flow (MAF) Sensor Performance" PHC ($10) "Powertrain Control Module (PCM)"
Here's the log file that shows the change beginning at frame 268:
Attachment 10167
I cleaned the MAF sensor this evening and took it for a drive afterwards, and to my surprise, it seems to have made a big improvement. I'll try to log data tomorrow evening to see if the problem is fixed.
Looks like you found your problem. If there has been a K&N filter in the box the oil could have saturated the element in the meter and cause your issue. the P0101 is a dead give away and will limit fuel if it is not giving feed back.
Quote:
Originally Posted by kst8engineer
We bought the truck with 120k miles and it was completely stock. 25k miles later the MAF sensor started acting up, still with the stock air filter. I don't know in particular what caused the MAF sensor to be contaminated, but I'm glad it's fixed now. I went ahead and flashed the truck this evening with two DSP tunes from Rob Coddens, and it's running great. Thanks to Big D and TheFermanator for all your help!Quote:
Originally Posted by Big D