at88mph

So, my 14 Z51 MN7 first had a blinking SES light.....for some reason, there were no codes figured just a loose plug wire so I reseated all the plug wires. Also, checked the resting battery voltage and have 12.6 so battery seems good. Went to try it again this afternoon and it was running rough still, and the SES light started blinking again. With it running though, I pulled the codes and got the following:

P0068 MAP/MAF
P0101 MAF
PO15B 02 sensor
PO15D 02 sensor delayed
Which I'm guessing all corelates together. Any ideas on where to look first? Thanks for any help!!!

96GS#007

The o2 sensor codes are basically saying the o2 sensors are not reporting fueling information back to the PCM within the time frame it expects. If it was a single code, then that's usually a bad o2 sensor. In your case, the codes mean both the left and right sensors are not responding appropriately. As such, it's unlikely the sensors are both bad at the same time.

P0068 means the MAP, MAF, and throttle position sensors are not correlated. This is confusing the PCM so it sets the code.

P0101 is the MAF as you mentioned and means the information it's providing to the PCM is out of range.

Check the simple things...make sure the air filter is clean. Make sure the the intake hose is connected to the throttle body. Examine all the wiring.

After the above, you really need a scanner to see what's going on. All of these codes together tend to point to a failing PCM. There's a slight chance the MAF could be dirty so you can take that out and clean it with electrical contact cleaner. Unfortunately, none of these items are cheap so firing the parts cannon at the car really isn't the way to go.

I guess you could try a hail mary and disconnect the battery and do a hard reset to see what happens. After that....gotta get something to log with or take it to a shop.

laserdude2215

I vote for a bad/dirty MAF.

at88mph

Thanks for the replies guys! I ordered a new MAF, plugs, plug wires, and a coil packs. MOST everything I've seemed to find points to a flashing SES light being spark related so I'm hoping I get lucky! I'll start with the new MAF and move on to the PITA of replacing all the plugs/wires/coils if that doesn't work Definitely hoping it's NOT the PCM!!!

at88mph

Just in case anyon searches and finds this thread. I found the issue. I replaced the MAF, coils, wires, and spark plugs. When I got to cylinder 8, I found this:


All the other plugs were fine, but this one was cracked and I'm assuming that's where my issue was. After replacing the plugs, the car now runs fine again. Thanks to everyone who replied for the help!

laserdude2215

Kudos to you for closely checking the plugs!! And, for sharing a successful repair.

at88mph

Thanks! and also thanks for the reply and help!

Tinkertech

Same thing happened on my son's 06 GT Mustang.

Luckly I had a scanner and was able to determine that cylinder #2 had a misfire. It also had a lot of other DTCs also.

Replaced only that #2 plug and all was well.

No parts cannon for me.

Tinkertech

LONG READ AHEAD BUT INFORMATIVE. HERE IS A STORY OF A REAL NIGHTMARE CONCERNING A PCM.

VERY happy it was not your PCM.

Heres a FYI story about a bad PCM on my hand me down to my son's 06 Mustang. I would not want to wish this on anyone.

I own a 2006 GT 4.6L Mustang, purchased new in 2006, which I believe has developed a PCM / ECM computer Issue.

Computer P/N:
6R3A-12A650-XB
VK-R3609
S/N: SX4B4K1DWYTS
.
Issue:
1) P0053, front O2 heater.
2) P0059 front O2 heater.
3) A/C intermittent operation.
4) MIL light ‘ON’.
5) All faults appeared at the approximately at the same time period.

Diagnostics:
Diagnostics using my Autel MX808 scan tool I obtained the following results:
Both front O2 heaters indicate their current at ~ 1amp, ( not sure if this is a measured current to the heaters or just a signal output from the microprocessor) on my scan tool, but still throws codes. O2 wiring and heaters ohm out correctly. ~ 5 ohms at the PCM connectors (on a Fluke 117). (disconnected from PCM). No opens or shorts to Gnd.
Computer is indicated to be energizing the A/C clutch relay, on the scan tool, but clutch is intermittent in operation. The PCM does not always provide the ground output signal to energize the clutch relay that is in the BEC (fuse / relay box) even though the computer indicates it to be ‘ON’ when viewed from my scan tool. No measured Gnd signal at clutch relay.
I ran a freeze frame on my Autel scanner and I can see the O2 heaters drop out for a couple minutes then come back on. I believe this is when the computer fails and sets the Mil light.
.
Background / Inspection:
I’ve been an qualified engineer / electronics lab tech for over 50 years and decided to inspect the inside of the computer. I was only able to inspect the top of the board due to it being RTV’d down onto the case. I did not attempt to remove it and did not want to send it off to a speciality shop for chemical removal of the RTV and overcoating. (as I have done in the past on boards). Visual inspection revieled that there was no broken or burnt components. No water intrusion or physical abuse. All solder joints on components (on the top side of board) appeared good under a microscope, board has never been worked on before, could not inspect the 3 I/O connectors solder joints for they are on the bottom of the board. (could possibly be intermittent). All connector pins good. All engine compartment Gnds cleaned and Ohm’d out good. All fuses and relays good. All connectors in both PCM and BEC cleaned and inspected. Car battery new, voltage steady and correct, engine On or Off. Alternator good with no excessive AC ripple. (~40mV at battery as shown on my oscilloscope ). Frequency correct, no bad diodes inside alternator.

Internet Search:
Internet search for a 2006 GT 4.6L Mustang indicating same issues, P0053, P0059, A/C intermittent clutch operation, that the PCM / ECM was bad and replacing it resolved all the issues. Don’t know if the computer was repaired or replaced with a new one. I could not find any new units available so I’m now considering having this one repaired if possible.


UPDATE:
I think I troubleshot the issue down to 1 chip on the PCM board. I always felt it was an intermittent solder connection on this board some where. Since I have an extensive background in electronics I gave it my best guess. The board is a real nightmare to work on, no schematic, no silkscreen, no part #'s or any data also the board is over coated with silicon and the board is RTV'd down to the case only allowing for me to see and work on the top side only. I reflowed the suspected chip and 3 days latter all issues are still gone. I will be running codes for the next week or so daily. We will see if it holds.


Update:
Well its been almost 2 weeks since I repaired my PCM that had the bad solder connections on a 48 pin QVN chip. Thank god it was not a 'balled' chip, I could never get a really good idea of what kind of chip it was even though I had the P/N. It seems to be a proprietary design by Motorola who also makes the board. Very little data on the chip only that it was for automotive emissions systems. Anyway so far the computer has been working great. I test for codes every day and none so far so I consider the issue fixed.

So if anyone thinks they have a bad PCM I sure hope they are available. The one for the 06 Mustang was not and no repair shop would touch it due to being RTV'd down inside the case and numerous other issues with this unit. So I had to fix it my self or the car would not pass inspection resulting in turning the car into scrap metal. NO INSPECTION = NO PLATES = NO INSURANCE.

Changing out the PCM for a junk yard replacement would of been a very expensive, new keys and all locks and ignition switch replaced and the unit would have to be programed by a dealership. Well over $2500.

Note: This Mustang was a garage queen in pristine condition so thats why I spent so much time and effort on it. I got very lucky.

Note:
The end of life of these cars will be the lack of spare electronic replacement parts. It may be a garage queen with very low mileage but when a necessary part, especially electronic, becomes unavailable or unrepairable you will basically have a very heavy paper weight.

ErnieN85

Good for you! I have always found that bad solder joints were often the cause

Tinkertech

On consumer electronics the manufacture uses 'lead free' solder which is vastly inferior to the original 'lead' solder.

FYI:
Units that ONLY use leaded solder for reliability:
All aircraft.
All spacecraft
Almost all Military equipment.
Anything that has to have a high reliability factor.

Bill Dearborn

I agree. The chip suppliers obsolete parts at a rapid rate. If a company uses the chips in their products they are given an option to make a lifetime buy or remap their design into a new chip architecture or do nothing. Most will do nothing as the return on investment is poor for commercial products. That is one of the reasons the F22 is so expensive. By the time the Government got around to making up its mind about purchasing the first version some of the original chips became obsolete and the design had to be remapped to the replacement chips taking more design and test time. Now close to 30 years later there are even more obsolete parts requiring replacement. The chip industry doesn't wait around for slow moving organizations to make up their mind.

Bill

96GS#007

How true. We were submitting obsolescence ECPs while we were still in EMD. The chip industry....besides not waiting around....isn't enamored with low volume production. "High Volume" in the military is a drop in the bucket for commercial firms. Mix in the requirement that chips need to come from trusted foundries and the cost goes through the roof.