Tinkertech
Junior Member
Hello everyone. I have been a long time reader but never posted. All my questions were answered by others.
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.
Question:
Does anyone have any direct experience with any PCM repair or exchange companies that have had a good experience with? Almost all the companies I have researched all have bad ratings. I wish I could just buy a new one but none exists.
Any insight or help would be much appreciated.
Thanks one and all.
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.
Question:
Does anyone have any direct experience with any PCM repair or exchange companies that have had a good experience with? Almost all the companies I have researched all have bad ratings. I wish I could just buy a new one but none exists.
Any insight or help would be much appreciated.
Thanks one and all.