Wich one is coil b 351

351 - coil #1
352- coil #2
353- coil #3
1391 - crank or cam sensor. It's located on the top driver side of the bell housing (transmission). Very common part to go bad. Buy a good one. AC Delco.

google it or better get the FSM for your car, and read how to do the tests, that prove what causes each DTC.
505 idle speed failure.
351
http://www.obd-codes.com/p0351

there are 5 engines, so first find that out,.
351
ignition Coil # 1 Primary Circuit Peak primary circuit current not achieved with maximum dwell time.
this means the coil primary is open (other books show the fail is for too low current (open coil in COP)

505
Engine started; system voltage over 11.5v and the PCM detected an unexpected voltage condition on one or more of the IAC motor circuits for 2.75 seconds with the IAC motor active.

id fix the 351, cop coil , its probably bad, or bad connections to it.
then clean the iSC,
then reset all codes, with a scan tool
drive 20 miles or until CEL glows, driving and the rescan.

Follow spark plugs wire,coils and module could be problem.

Click on link.http://www.autozone.com/autozone/parts/Duralast-Ignition-Coil/1972-Ford-Mustang/_/N-ipo32Z9n80r?itemIdentifier=111849_0_0_

1. Check for power to the ignition coil when cranking.

2. Check continuity between the Powertrain Control Module (PCM) and the coil on the coil ground circuit wire.

3. Check connections at the coil and at the PCM.

4. If good, replace the ignition coil.

5. If the problem is still there, replace the PCM.

Here is the code description and the possible causes for the code.



Then, with all that being said, the MOST LIKELY cause of your problem is an ignition coil breaking down after it heats up and is put under load.

That code is for Engine control module engine immobilization input circuit malfunction. Ignition coil is ok.

the fuse should be under the left side of the hood if you are standing in front of the truck its going to be in the insterment panel with the relay and other things check that out and if the fuse is fine then check the wireing

ignition control box on left fender

what module is it in?