Good day! I have a 2007 ranger sport 4x4 extended cab with a 4.0L engine.
I have been having problems recently which was causing my Speedo, tach and temp gauge to cutout while driving.
The first time it happened I did a rolling restart thinking it might be intermittant and a restart might fix it.
After shutting off the ignition and trying to restart,the engine would not crank and my anti-theft light was blinking rapidly.
A quick google on the side of the road found an article that said disconnect the battery for 10 mins and then re-connect and restart the engine.
It worked. I did some research here and on the net to try and get to the bottom of the issue.
When it happened again I shut the truck off and waited for the light code. It was 1-6 no communication.
I do not have a workshop manual yet (working on it) but I did find a post here that discussed a self diagnostic using the instrument cluster.
While the truck is not starting and the diagnostic is running the guages all sweep fully so I know they are fine.
It did list 3 DTC's in the test, C100, C002 and another I think was 9698. I have it written down at home.
Not your normal numbers for DTC's and I could not find a crossreference for them anywhere on the internet.
When I had the truck going again after another overnight battery disconnect I check for DTC's with my ELM327 adapter and only got the Emissions DTC I have been having probably due to my Fuel cap as the fuel cap light comes on now and again.
I tried it again and had it search for pending codes or not completed codes/tests and got one for the PCM. Again it is written down at home.
I wrote the codes down. The tach and speedo died again right then so I shut off the engine rechecked for codes.
I could connect to the ELM327 but could not connect to the computer.

So... My line of thought is there is an issue in a connection to the PCM somewhere due to corrosion etc. or it is dying.
I looked at some testing sequences found for other year Rangers that spoke of checking for DTC's when the PATS is having these issues so I believe the PATS alone should not interfer with connecting to the computer for DTC's.
This morning it finally would not start altogether after leaving the batt disconnected overnight.

I found an ISO file for 2007-2009 Rangers so I hope to get a flow chart tonight as long as it is for North American vehicles as I saw some manuals for Aussy and Thailand Rangers but did not want to assume they were the same.

If anyone can confirm the Checking of DTC's with this issue that would be great.
Also if replacing PCM can anyone confirm that it would need to be matched and progrmed before it will work in the vehicle?
In other words a trip to the dealership.

Cheers.

 

I should have also mentioned I have two keys and neither of them work.

 

The "Gas cap" light means the EVAP system has a leak, which can be because you forgot to tighten gas cap at last refilling, but has nothing to do with the actual gas cap, just FYI
But nothing to do with the no start and PATS

PATS code 1:6 means the instrument cluster(PATS Module) and engine computer(PCM) are not having a successful "handshake" on the CAN Bus(vehicle data network)
This can be voltage related
Unhooking the battery is not done to reset the electronics in this case, its to let the battery rebuild a charge if it was low
Test battery voltage to take that off the table
12.8v is a new battery
12.5v is a 3 year old battery
12.3v is a 5/6 year old battery and time to shop for battery sale

12.2v or less is a dead or bad battery, change it

After testing battery volts, turn on the key and test volts again, if its dropping too low that could be your problem, garbled "handshake"

One heads up, if you try to start engine 4 times with Theft light flashing fast, PCM will go into lock down, and you have to wait 90min or so before it will reset, so even if you fixed a problem you wouldn't know it, unhooking the battery doesn't change the wait time

The CAN Bus is a 2 wire network that connects all the modules in the vehicle, and its these 2 wires that your OBD2 reader uses to talk with the PCM and the other modules
The fact that you can get DTC codes from the OBD port means the PCMs data lines are OK, so most likely is the instrument clusters lines are not OK

Its odd you are not seeing PATS codes on the instrument cluster, seen here: https://www.launchtech.co.uk/common-...lt%20codes.pdf
Yes UK Ford is the same as ours

You should be getting Bxxx OR Uxxx code same a flashing light 1:6 code, and you are not, which again points to cluster issue

If battery is not the issue not sure where you can go from there, you could pull the cluster and check the wires, unplug and plug back in connectors, but you can NOT swap it out, only Ford Dealer can with the HEC units, because of the "handshake"

 

Thanks for your reply.
As far as battery voltage goes during the instrument cluster self test it indicated battery voltage was 12.5. That was obviously with the key on.

Lock down is a possibillity as I did attempt starting a few times quickly when I was near the end of the limited testing I did.
More out of frustration than anything useful.

To clarify I could not communicate with the bus and read codes through the OBD2 port while the issue was occuring. Only through the cluster test and the codes from that test did not make any sense.
Maybe the difference with the code numbers in the cluster test are due to them being hexidecimal or something like that?
I could only retreive codes when the truck was working without the anti-theft light on and the truck working normally.

So to your knowledge is there a module in the Can Bus network that is in series with the OBD port and the computer or are they all in parrallel?
Anything between the OBD2 port and the computer that would cause the loss of communication besides harness connections?

Cheers

 

All are parallel, but the PCM does control one wire to OBD port

Here's a CAN Bus diagram for 2008 Ranger, 2007 will be the same

Also the PATS wiring, the CAN + and - wires run to PCM to give it the the "OK to Start" or the "Don't start" message, but no message is the same as "Don't start"

 

The big question is if there is a PATS issue with my ranger then I should still be able to read codes when the anti-theft is enabled and preventing starting?

Earlier you mentioned the instrument cluster (PATS module) and how it performs the handshake with the PCM.
In an other post I saw : https://www.ranger-forums.com/genera...2007-a-151768/ it was said that there was no separate PATS module in the 2007, that it was integral with the PCM.

I have still not looked it up in a manual.

 

PATS is in the PCM in as far as thats where the system is used, disables fuel systems and starter relay
But it passes thru the HEC(dash) first, key's number is read by the HEC and sent to PCM, so PATS is in both

In 2003 and earlier Rangers the Transceiver(antenna around key slot), was connected directly to the PCM, so no other "module" involved
2001 PATS diagram below
And Ford could have left it this way until 2011, but they didn't, they move "part" of PATS to the HEC in 2004, why?
I don't know, but its there

And from other threads out there people that were trying to disable PATS via new PCM software, and on 2003 and older it would work, but on 2004 and up Rangers(thats when HEC was added) they had problems, 2004 to 2011 used HEC
2005 Rangers didn't have PATS, Ford skipped that year

So HEC is certainly parts of the PATS system in 2007, how much of a part Fords not saying, never has

1999-2000 Rangers had an actual separate PATS module, so maybe HEC "PATS module" is the wrong term, but I don't think so in as far as its separate from the PCM, like in the 1999/2000 Rangers

 

I would definitely be pulling the central junction box's (interior fuse box behind passenger kick panel) connectors out and looking for corrosion there. I've seen quite a few 2004+ Rangers develop all kinds of strange symptoms from no-starts to wipers coming on when you honk the horn, and trucks that wouldn't shut off when you remove the key. They all had corrosion on the terminals of those connectors.

 

I am thinking the same thing. I just have not had the time to get to it. There have been no PATS codes when the truck was working after the no starts. But there were PCM codes that were pending as if it was intermittent. Also the OBD2 port will not connect to the computer to read codes when it happens. I have to work on the house sat and sunday but on monday i am opening things up and checking for corrosion at harness connections. I have a manual now with pinout tests so i should be able to get to the bottom of it.

 

Fixed it. The main connector from the interior to the PCM was loose and causing an intermitant open circuit on pcm circuit 23. The handle of the connector worked but did not lock as there was a broken plastic tab. Gravity and bumps did the rest I guess. Thats why it didn't throw any PATS codes as it was a communication bus issue not a PATS issue. I used two plastic tied to keep the connector together and it is working.

 

Good work

That was a hard one to find

 

Thanks for the help on this. I enjoy talking out technical issues. There is always someone who has had a similar experience that can provide another set of eyes so to speak.

 

As a lurk on this web site, I just wanted to say thanks to all the Ranger folks for their help, and to the owner for posting feedback, WITH A PICTURE! What a valuable resource.

My truck is currently starting, idling normally, drives for a few moments but dies after I come to a stop with the pats light illuminated. Because of this, my suspicion is not in the typical places like inertia switch, battery (brand new), etc. It has a very distinct, "nope, shut'er down", sort of behavior. I sincerely hope that the issue is a simple connection issue and not a 1000$ load of sensors and relays to figure it out.

 

Welcome to the forum

PATS is only active PRE-start up, it can't stall an engine that's already running
PATS tests the key in ignition ONE TIME, with key on, if key passes the test then THEFT light goes off, if it doesn't then THEFT light flashes rapidly and No Start
If you don't turn the key off again then there is no re-test of the key, PATS key test only happens when computer is re-booted, key off and then on

So your symptom doesn't read like a PATS issue
PATS is notoriously sensitive to voltage
Test battery voltage, key off, 12.3-12.8volts is acceptable, 12.2v or less is not
Start engine, battery should now show 14+ volts, alternator is working, under 13.5v means its not working

Cold start should have idle RPMs above 1,100, then a slow drop over the next 5-8minutes to about 750rpms(depends on year and transmission type)
If that's not happening then IAC Valve or ECT sensor may be failing, either can cause stalling when stopping, especially with automatic trans

 

Thanks for the detailed insight! You da man! (Or lady)

The truck is a 2004 FX4/XLT 4.0sohc 5spd with 187k on it. I should add that the truck does nothing different, other than dying when attempting to drive. I can hold rpm while idling no problem.

I replaced the battery after discovering a bad cell a few days ago. First indication was loads of corrosion, and then confirmed it was toast at parts shop. Solved - purchased quality battery with warranty. Before any diag, I thought it was maybe the positive battery cable since it has multiple ancillary terminals that go everywhere and is also corroded. Still haven't ruled this out. I can't remember the code, but the reading from Forscan (I still find this name very amusing), was voltage too low. I know bad grounds and connections are critical for the ECM, but why would it start and run as usual if the cable was bad? I will check the other possible solutions you provided and follow up.

Cheers!

 

After throwing a bunch of parts at it, a compression test revealed 70 psi in cyl 6, which is supposedly causing the computer to shutter down for imminent failure. I certainly hope this is the case, and that the 8500$ job I'm paying for will eliminate this problem altogether (Jasper reman with a pricey mechanic). I was going to swap it myself at a buddy's place, but I run a painting business and don't want to hurt myself on the weekends and after work. Also, I don't want to mess something up and get it stuck in his garage. Anyway, thanks so much for your input on my problem. Will update when the new engine is in.

Cheers.

 

Computer doesn't shut down anything because of misfires(low compression)

Low compression on a few cylinders would cause engine to stall, on the 4.0l SOHC that could be because timing gear slipped, they are not keyed to cam
Compression = power, so yes holding RPM in neutral wouldn't be an issue, under load(driving) it would be an issue

Can argue with a re-built engine, but that does seem to be a bit extreme for described symptoms, if its just a burnt valve or timing issue
If you had rod knock then maybe, lol

 

I can see how that would be the issue, as it's exactly that problem. It'll sit and burn a tank of gas just idling, but under load it shuts off as soon as the rpm drops. By the time I bent my knee and sent it to a professional, I couldn't even hobble down the road or keep it running anymore. Friend ended up towing me with a chain. I now wait with bated breath for my rig to be back and basically brand new. I've already done so much, I've basically bought a new truck. lol

This may seem extreme, but the way it's designed, I don't want to remove the engine to fix any cam related issues, seeing as the cams are opposed on this engine. Really dumb if you ask me, I've done many timing belts, even dohc before. Never had to pull the whole engine. This is what led me to the decision to just buy the whole damn thing. I'm married to it now, and selling at a loss brings me back to spending at least 5k for another Ranger with this particular set up - in good condition with low miles. At least now I can trust it to be turn key go to run my business.

Will update after I get back and see how it's doing.

Cheers

 

just wanted to say thank you for posting this. ExCt same symptoms. No idea where to go after the battery and fuse and tried this and worked. Mine didn’t even look loose though but I just pushed on it and it went back in. The symptoms felt like a loose connection though so thisade sense. I now have a zip tie around it.

 

Where is this connection located on the vehicle exactly?