blackf150

I am new this site. I have a black 2005 ford f150 on 20" wheels. The truck has a cold air kit and dual exchaust cat back system. I do not like to join a site and start off by asking for some help. I have the 5.4 engine and it is running like CRAP. I hooked my code reader to it and am getting codes P0506 and P0357. Can anybody help me with this. What does it mean by Igintion Coil G primary/secondy circuit. I just replaced all the coils and plugs about 2 months ago and the truck stays sitting all week. Any help would be great.:

KLC

Welcome! Any pictures?

blackf150

not yet but i will get somw up this week

danthurs

This P0506 code is one that's sometimes triggered on vehicles that have electronic throttle control. That is, they don't have a regular throttle cable from the accelerator pedal to the engine. They rely on sensors and electronics to control the throttle. In this case, the P0506 DTC (diagnostic trouble code) is triggered when the PCM (powertrain control module) detects an engine idle speed that is lower than the desired (pre-programmed) RPM.

A P0506 DTC trouble code may be caused by one or more of the following:

• A vacuum leak
• An air restriction in the intake air path or exhuast
• A faulty positive crankcase ventilation (PCV) valve
• Damaged/failed/dirty throttle body
• Internal engine problem
• Failed PCM

The COP (coil on plug) ignition system is what is used on most modern engines. There is an individual coil for each cylinder that is controlled by the PCM (powertrain control module). It eliminates the need for spark plug wires by putting the coil right above the sparkplug. Two wires are dedicated to each coil. One is a battery feed usually from the power distribution center. The other wire is the coil driver circuit from the PCM. The PCM grounds/ungrounds this circuit to activate or deactivate the coil. The coil driver circuit is monitored by the PCM for faults
If an open or a short is detected in the driver circuit for coil #7, a P0357 may set. Also, depending on the vehicle, the PCM may also shut down the fuel injector to the cylinder also.


Potential causes of a P0357 code include:

• Short to voltage or ground on COP driver circuit
• Open on COP driver circuit
• Loose connection at coil or broken connector locks
• Bad Coil (COP)
• Faulty Powertrain Control Module

So looking at the descriptions you have a problem with coil #7. Look this over. If you find no problem, such as a loose connection, then we will help you with some testing. Your P0506 code is likely caused by the P0357 code. So I would ignore that one for now.

danthurs

I moved your post to the proper section and changed the title to be more descriptive.

Trent

Try cleaning your throttle body. My truck threw a throttle body code after I changed my plugs and just a simple cleaning removed it. Hasn't been back since and that was over 6 months ago.

blackf150

Thanks for all the info. I did electrical test today and I think I have a bad coil. I have a new one on the way. As far as cleaning the thottlebody what do you suggest to use? My truck has about 205,000 miles on it.

danthurs

Throttle body cleaner. Remove the throttle body, remove the sensors, and clean it. Put it all back together and your set. Willing to bet when you replace the bad coil, both codes go away.

blackf150

Just wanted to follow uo with everyone. I got the new coil in and installed today.Deleted the codes and took the truck out for a test drive. So far everything is good. Running like it was new again. Hopfully this took care of the problem time will tell. I want to thank everyone for there help with my problem.

danthurs

Judging from what I see in your codes, that should fix it all up. Glad to hear it's working again.