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  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 V6 Mustang Tech

PCM and the gauges

  • Thread starter Thread starter Harveyj1965
  • Start date Start date Jun 3, 2019

Harveyj1965

New Member
May 16, 2019
13
0
1
Bakersfield California
Jun 3, 2019
#1
  • Jun 3, 2019
  • #1
My 2001 GT mustang 4.6 I replace all the wiring harnesses PCM the gauges my question is does the gauges have to match the PCM numbers the last 2 # lb the gauges I'm not too sure I had a guy come out and was supposed to marry everything together and apparently didn't work the dash comes back on and there's. Lines going through the odometer I've checked all my fuses all the fuses are good okay so f2.34 has no power has no power on and off f2. 2 has no power on or off f2.8 has no power when off but has power when on
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Jun 3, 2019
#2
  • Jun 3, 2019
  • #2
Harveyj1965 said:
f2.34 has no power has no power on
Click to expand...
IF Fuse F2.34 does not have key on power in/out, then it should be EXPECTED that F2.2 and F2.8 will also not have power. F2.34 is the pilot duty circuit for the CCRM. It would also be expected that PATS re-programming would fail because the PCM is not being told to power itself on.

The usual cause for no power in F2.34 is a bad ignition switch. Given the amount of work done to this car it also stands to reason that the problem could be somewhere outside of the "usual" cause. This likely will require additional detailed trouble shooting.

Can you confirm:
  • IF there is always on power at fuse F1.3
  • IF there is key on power at fuse F2.28. If there is power in F2.28 the but not F2.34 there's a fault inside the CJB.
  • IF there is key on power at fuse F2.18. If there's power in F2.18 then part (a gang) of the ignition switch is functioning.
Do you have a copy of the Ford service manual and wiring diagrams? There is a section regarding HOW to trouble shoot the ignition switch. If you are interested in getting a copy for yourself I maybe able to help. PM if interested.


1999-2004 MY fuse panel schedule:

1999 Mustang GT with 2001 motor swap, wont fire. Please help

First off thank you for taking the time to read this, I hope that you will be able to help me out in some way to get a 4 month project off the ground and back onto the streets. I'm not a master mechanic but know just a little bit, enough to do your typical maintenance, overhauls, and swaps. I...
www.allfordmustangs.com

F1=BJB=Battery Junction box located engine bay.
F2=CJB=Central Junction Box located driver's kick panel.

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

ForScan ODB2 scanner w ELM327 USB

ForScan ODB2 scanner w ELM327 USB

While working on your car have you ever wanted: to find an ODB2 operational PID value (say fuel pressure or MAF)? How about graph a PID value over time? Or compare multiple PID's over time? Access a bi-directional PCM control such as test a...
www.stangnet.com

But all of the above has been covered previously. So this isn't really any new information. I encourage you to double check your work and to be through with reporting the tests results as the details matter. The details can help focus where to look.

If you are looking for confirmation that fuse F2.34 holds the key, then consider a possible "by pass" test. Get yourself an "add a fuse" or "add a circuit". Use the pigtail to "inject" +12 volts into the circuit. This should cause the CCRM to pull up and power F2.2 and F2.8. Also looking to see IF the PCM will now "talk" to an ODB2 scanner/reader.
 
Last edited: Nov 3, 2019
R

Reckless_b

Member
Nov 1, 2019
43
3
18
South Yorkshire U.K.
Nov 2, 2019
#3
  • Nov 2, 2019
  • #3
This could be part of the problem I’ve been having, I have no power at f2.2 although I’m certain that only that fuse is without power, I’ve rigged up a separate supply to the ccrm plug wire 12 and the cars a runner but I can’t get the OBD2 tliad up, I’m much happier now I’ve got the car running but would prefer it to be without being bodged
 

wmburns

SN Certified Technician
Aug 14, 2009
5,892
514
204
Houston Texas
Nov 2, 2019
#4
  • Nov 2, 2019
  • #4
Your post does not state the test results of fuse F2.34, F2.2, and F2.8 key on test.

IF there is no key on power at Fuse F2.2 but there is key on power at F2.8, the odds favor a wiring fault OR a problem right at the CJB fuse box. If this were my car I would removed the F2=CJB and inspect the back for evidence of heat or rodent activity.

F1=BJB=Battery Junction box located engine bay.
F2=CJB=Central Junction Box located driver's kick panel.
 
Last edited: Nov 3, 2019
R

Reckless_b

Member
Nov 1, 2019
43
3
18
South Yorkshire U.K.
Nov 2, 2019
#5
  • Nov 2, 2019
  • #5
I’m almost certain that only f2.2 is without power when key on, I won’t be able to check again until tomorrow morning.
All I have been able to do with the f2 fuse box is to remove the mounting screws and half turn it over, too much steel work, not enough slack wire on the wires, I couldn’t see any damage or burnt up wiring,
The car is a 1999 model with just over 32000km showing, imported from Japan
What are the CJB and CJC
I’ve posted the write up on what I’ve done separately, “do I have two faults”
 
R

Reckless_b

Member
Nov 1, 2019
43
3
18
South Yorkshire U.K.
Nov 3, 2019
#6
  • Nov 3, 2019
  • #6
I’ve been out to test the aforementioned fuses and I guess that all the pulling, tugging and twisting of the wiring to the fuse board has “fixed “ the fault, although I know it’s not a real fix.
I had “key on” power at f2.34, f2.28, f2.18 f2.8 and finally f2.2
I had suspected that power had come back to f2.2 as the odometer display had returned without the jumper wire supply being on.
I think my next job is to reconnect the original supply to wire 12 in the ccrm plug but to make it easy to swap back to the jumper wire if needed.
Any thought or suggestions appreciated
Many thanks
Bill
 
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