Ford Transit 2003 2.4 Duratorq

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Right, Pats is linked to the starter circuit. If the Pats fails to un-lock, you have no crank !

The PCM is the Pats master, so if the PCM is off line, you will have no crank.

You need to understand “how” the PCM powers up, and then the rest is a walk in the park.

Without a diagram to hand, you will have to bear with me.

PCM will have a permanent power supply, and a switched power supply.

Check first if they are present, if not, trace back.

Confirm correct grounds at the PCM, you will have a few, but all going to the same ground point.

Now, when the PCM receives the ignition sense, it will perform a POST. (Power On Self Test). If the POST passes, the PCM will switch a ground to the power hold relay, and that will provide about 3 additional lives back into the PCM.

So, the PCM powers up in two stages !!

At the first POST stage, the PCM checks the 5v Vref for path to ground. If a short is noted, the PCM inhibits the second part of the power on, as it knows it will result in a damaged module.

This stage is what catches people out.

So, if you have constant and switched live at the PCM, but you have no earth switch to the power hold relay, it’s failed the Vref. (That’s the 5v that’s provided from the pcm to the engine sensors). So, an internal short in something like the EGR position sensor, or pedal sensor for example can prevent the PCM powering up. That’s the one that blows peoples peanuts. !

Remove harness connections to all engine sensors that have a Vref. Do you get communications back ? If you do, reconnect one at a time to find the offending part.

If they are all disconnected, and still no communications, remove the PCM harness plug, and check each Vref wire for a path to ground !

If no faults are found, the module is goosed !

Now, if the PCM is closing the power hold relay, and you have correct battery voltage back to the PCM from the relay, (remember to volt drop test the lives), then I’m afraid it’s as simple again as the PCM is goosed.

ALL FORD PCM’s POWER ON THIS WAY. Its worth remembering.

See if you can find a diagram and follow it, you will see what I mean.

Simples BigGrin BigGrin

Author	Message
Tony5	Posted 3/7/2010 4:48:47 PM
Forum Technician Group: Advanced Members Last Active: 4/12/2012 11:14:22 AM Posts: 726, Visits: 12,823 730	All, Have the above for one of my customers [civil engineers, so it's having a hard life]. It won't even crank, i have no comms with the pcm or pats [using IDS]. The dash lights up ok. When i go in manually, i can get comms with the vehicle, but again nothing with the pcm. pats comes back with no fault code, but no comms with the module due to there being either no supply, no earth, or a faulty module. I'd have thought the vehicle would at least crank, and am wondering whether i have 2 faults [one being a faulty starter motor, causing a short?]. It wouldn't surprise me if the starter motor had been burnt out with the customer [or rather one of their employee's] keep trying to start it. Can anyone tell me where pats is so i can test for feeds and earths? Pm's are fine due to the security nature of the problem Another piece of info, is the van is one of many [a fleet of them countrywide], the company is a national one. Can anyone help? Tony 'Learning All The Time'
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*K And R*	Posted 3/7/2010 5:02:38 PM
Forum Master Technician Group: Moderators Last Active: 2 hours ago Posts: 9,068, Visits: 24,388 9,440	Tony. Unless i very mistaken, PATS will be inside PCM and the starter is most likely FOOKED due to a failed dual mass. Kev. "If you dont KNOW how it works, don,t try to test or fix it"
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vitos	Posted 3/7/2010 5:39:31 PM
Forum Apprentice Group: Forum Members Last Active: 1 hour ago Posts: 96, Visits: 1,794 114	Hi Tony, pats is internal to pcm on this year. check all fuses very closely are you able to read mileage on dash panel relays are pretty poor on these aswell
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Tony5	Posted 3/8/2010 5:04:40 PM
Forum Technician Group: Advanced Members Last Active: 4/12/2012 11:14:22 AM Posts: 726, Visits: 12,823 730	Thanks Kev and Vitos, I thought as much regarding pats, but wanted it confirmed, as i certainly wasn't 100% I'll be speaking to the company tomorrow, and will ask for one of their mechanics to have a look at the starter motor. I'll also tell them about a suspected dmf [never thought of that one, cheers Kev]. Vitos, As far as i can remember, the dash was ok, i'd also checked all the fuses, and bridged the starter relay using a 5a fused bridge. I will ask them to double check the dash though [just to make sure]. I've got to do some of this remotely as the customers workshops are 15 miles away, so it costs them when i turn up. I'll report back when i've something solid [or not, eh Kev?] Thanks again gents Tony 'Learning All The Time'
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Speedy	Posted 3/8/2010 5:53:23 PM
Forum Technician Group: Forum Members Last Active: 10/14/2011 10:06:03 AM Posts: 582, Visits: 2,236 586	Have problems with the main battery earth and the engine earth leads on these
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Tony5	Posted 3/8/2010 6:16:51 PM
Forum Technician Group: Advanced Members Last Active: 4/12/2012 11:14:22 AM Posts: 726, Visits: 12,823 730	Thanks Speedy, Will take that into account as well, especially as i haven't checked the battery earth I can't believe how i still miss basics like that The engine earth looked ok though. Tony 'Learning All The Time'
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cartech	Posted 3/8/2010 6:21:09 PM
Forum Master Technician Group: Advanced Members Last Active: 5/11/2012 4:18:57 AM Posts: 1,338, Visits: 1,764 1,361	For some strange reason, Ford put a ballast on the earth on these vans, and they're very prone to failing. The ballast is located near the floor, by the seat buckle. The RAC put an extra earth on their vans because of the problem. If I understood women as well as I understand cars, I'd be the envy of every man.
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Radnorman	Posted 3/9/2010 1:56:27 AM
Forum Master Technician Group: Advanced Members Last Active: Yesterday @ 3:29:51 PM Posts: 1,299, Visits: 5,193 1,332	cartech (08/03/2010) For some strange reason, Ford put a ballast on the earth on these vans, I had understood that these leads were fused. The February Edition of Unipart Automotive's Workshop Focus describes them as fused. I have looked at Wikipedia to gain a fuller understanding of the term "ballast". I still don't 'get it'! To me, it is a fused lead. I stand, to be corrected.
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Andy-01	Posted 3/9/2010 2:09:49 PM
Forum Technician Group: Forum Members Last Active: Yesterday @ 4:26:34 PM Posts: 526, Visits: 1,638 541	Right, Pats is linked to the starter circuit. If the Pats fails to un-lock, you have no crank ! The PCM is the Pats master, so if the PCM is off line, you will have no crank. You need to understand “how” the PCM powers up, and then the rest is a walk in the park. Without a diagram to hand, you will have to bear with me. PCM will have a permanent power supply, and a switched power supply. Check first if they are present, if not, trace back. Confirm correct grounds at the PCM, you will have a few, but all going to the same ground point. Now, when the PCM receives the ignition sense, it will perform a POST. (Power On Self Test). If the POST passes, the PCM will switch a ground to the power hold relay, and that will provide about 3 additional lives back into the PCM. So, the PCM powers up in two stages !! At the first POST stage, the PCM checks the 5v Vref for path to ground. If a short is noted, the PCM inhibits the second part of the power on, as it knows it will result in a damaged module. This stage is what catches people out. So, if you have constant and switched live at the PCM, but you have no earth switch to the power hold relay, it’s failed the Vref. (That’s the 5v that’s provided from the pcm to the engine sensors). So, an internal short in something like the EGR position sensor, or pedal sensor for example can prevent the PCM powering up. That’s the one that blows peoples peanuts. ! Remove harness connections to all engine sensors that have a Vref. Do you get communications back ? If you do, reconnect one at a time to find the offending part. If they are all disconnected, and still no communications, remove the PCM harness plug, and check each Vref wire for a path to ground ! If no faults are found, the module is goosed ! Now, if the PCM is closing the power hold relay, and you have correct battery voltage back to the PCM from the relay, (remember to volt drop test the lives), then I’m afraid it’s as simple again as the PCM is goosed. ALL FORD PCM’s POWER ON THIS WAY. Its worth remembering. See if you can find a diagram and follow it, you will see what I mean. Simples Edited 3/9/2010 2:11:23 PM by Andy-01
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cartech	Posted 3/9/2010 4:10:02 PM
Forum Master Technician Group: Advanced Members Last Active: 5/11/2012 4:18:57 AM Posts: 1,338, Visits: 1,764 1,361	My bad. It's a fusible link. If I understood women as well as I understand cars, I'd be the envy of every man.
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Ford Transit 2003 2.4 Duratorq - None Start

Ford Transit 2003 2.4 Duratorq - None Start

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