Please Help P0320 p2106 2005 Explorer XLT 4.0L 55k miles

[nycnative]

Hi and thanks in advance for any replies. My 2005 Explorer started behaving erratically about 3 days ago. To make a long story short, I hooked up my scanner and got P2016 and P0320 codes. I cleared the codes, took apart the throttle body, cleaned it all out like new, checked the voltage to the TPS and it measures .88v at idle and max is about 3.8v when the pedal is pressed. cranked it and it started up and after about 5-10 minutes same thing. wrench light comes on along with service engine soon and failsafe mode. Everything I read points to the TPS but mine appears to be working. I'm not sure what else to check. Any advise is much appreciated. thanks!

 

[sgully67]

Hi, I'm an auto technician with access to Alldata. Looked up those codes for you. While the p2106 is for the tps p0320 does not. That code is for erratic ignition. As for the tps can you do a sweep test with a scope? Even though min and max are good may be glitching somewhere in between. The p0320 code points to the crank sensor. Diag for p0320 also suggests that what is causing the p0320 may be responsible for the p2106 as well. Hope this helps.

 

[nycnative]

Thanks sgully67. Can I diagnose the crank sensor in a similar way as the TPS? meaning, are there voltage bounds that I can test for? I read somewhere that if the CPS is bad then I wouldn't get a spark and the engine wouldn't run. I'm not sure how accurate the previous statement is.

 

[sgully67]

No you can't use a standard volt meter. You need to use a scope to check the square wave the sensor is sending out. If the square wave isn't nice and crisp the engine will still start bad the timing can jump around a lot.

 

[nycnative]

Hi. just to follow up. it was the harmonic balancer that failed. it separated and ate into the crankshaft position sensor. Replaced the harmonic balancer with a part from advance auto parts (about 100 bucks) and the sensor from advance also (about 25 bucks). cleared the codes and it fired right up.