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99 Mustang Gt Instrument cluster and pcm

  • Thread starter Thread starter Hellmo
  • Start date Start date Oct 29, 2020
  • Tags Tags
    hec instrument cluster pats issue pcm
H

Hellmo

New Member
Oct 29, 2020
1
0
1
Florida
Oct 29, 2020
#1
  • Oct 29, 2020
  • #1
What's the best way to clear codes in the instrument cluster? Trying to figure out a pats issue. Found out the pcm in the car was not communicating with obd2 so I swapped a donor pcm and instrument cluster that came with the car in. Was told the cluster and pcm were out of the same car by seller. No dtc's with obd2 reader (cheap one). When using cluster diagnostic mode, the code for security values in cluster and pcm don't match was shown. I want to try and reset the codes so I can make sure its not from a previous swap the seller may have tried. Donor PCM connects to obd2 reader and also mileage shows up. I know they can be married at a dealer but I don't have one close, nor a way to get car there (money). Are the codes stored in the cluster or the pcm? Sorry for the rambling post and million questions. Thanks for anyone's help in advance.
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Oct 31, 2020
#2
  • Oct 31, 2020
  • #2
Just wondering. How do you know that the cluster and PCM are able to "talk" to each other?

Have you CONFIRMED that the PCM is actually getting power? Powers and grounds at the PCM? You are aware that IF the PCM is not getting power this will appear to be a PATS issue.

Does the cluster display all dashes (-------) or mileage?

IMO your problem is much more basic than clearing codes.
 

SMOKEDYA

20+ Year Stangneter
Jul 13, 2003
3,637
8
79
Tucson AZ
Oct 31, 2020
#3
  • Oct 31, 2020
  • #3
Having sorta this same issue. My 02 gt cluster reads all dashes cranks wont start no fans come on no fuel pump prime, theft light flashes rapidly then goes out briefly followed by what i have read is a code 16. Neighbor plugged in his scanner to my OBD port and ECM is not communicating with OBD port. Previous owner replaced CCRM,key antenna for key,fuel pump driver, fuel pump
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Nov 5, 2020
#4
  • Nov 5, 2020
  • #4
Here's some information that IF followed would get you well started on the road to finding a solution.

1996+ Crank with no start check list

1997 mustang wont ignite

Hello lets start with I have a 97 mustang gt v8 standard I had new engine transmission ect put all new well last month i shut the car off and had no power at all bought a new battery and alternator got all power back but it wont ignite brought to mechnic for a month all sensors codes ect are fine
www.allfordmustangs.com
 

SMOKEDYA

20+ Year Stangneter
Jul 13, 2003
3,637
8
79
Tucson AZ
Nov 6, 2020
#5
  • Nov 6, 2020
  • #5
wmburns said:
Here's some information that IF followed would get you well started on the road to finding a solution.

1996+ Crank with no start check list

1997 mustang wont ignite

Hello lets start with I have a 97 mustang gt v8 standard I had new engine transmission ect put all new well last month i shut the car off and had no power at all bought a new battery and alternator got all power back but it wont ignite brought to mechnic for a month all sensors codes ect are fine
www.allfordmustangs.com
Click to expand...
Thanks for the response, I actually googled this issue and ran threw the tests you listed.. said it! Part out!
 
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