About a year ago my truck's original CPS went out and I had to get the truck towed home.

I replaced the CPS with a BW unit. It went OK but would occasionally give something I would describe as a mis-fire.

I ordered the Motorcraft replacement from RR and fitted that. Perfect until Friday night, heading down a steep descent in wet and fog, been backing off in 2nd at about 60kmh and the engine just died - like it was turned off.

I did have the HID foggies on at the time - the ballasts are behind the grill, only seperated from the CPS by the thickness of the radiator.

Pulled over and pulled up. Waited 20 seconds & tried a re-start - fired up as normal. I've driven about 400ks since - all daytime - & not a peep. Checked the codes, P0340 CPS malfunction was there, along with the usual AIH delete & EBPV delelte caused codes - cleared the codes.

As you'd guess, my wife has expressed no-confidence in the truck, & to make matters worse, the MIL and SIL were in the truck at the time.

Opinions? Could it be just a one-off? Could water have caused a momentary bad connect, or the noise from the HID ballasts? Should I risk replacing it with another CPS which might be worse? I have 2 spares in the truck (1 BW and 1 other brand).

I can't move the HID ballasts easily, but I could try to shield them. Any ideas?

 

Simon , they have had trouble with the BW cps , mainly in the rain when the wipers are being used , there is some interference with the signal from the wipers , this was posted on another forum

I tried the BW CPS but I can't get it to work right with the wipers on intermittent. It will kill the engine after a couple of minutes. I was reading another post that said the wiper motor generates electrical noise which messes with the CPS signal. Has anyone tried installing a noise filter using capacitors across the wiper motor wires. It works for CB radios

If you shield the ground wire for the pcm it will fix the problem, you can get some EMI Ferrites at Jaycar , this or similar
The ground wire for the pcm and wipers is on the drivers side fire wall.

Ferrite Bead For EMI Suppression - Pk.6 - Jaycar Electronics


I still carry a spare black CPS in the console just in case , but have the recall (grey one ) in there now , after all it's only a 10mm bolt and some dirt on your shorts and your going again.

 

Actually, the HID ballasts is probably a furphy - I'd just fitted them a couple of weeks before.

My current CPS is a Motorcraft unit, and I had the wipers on intermittent at the time.

I remember reading something about it now, but didn't pay it much attention as I'd never suffered the problem before.

I'll chase the Ferrite Bead fix this w/e!

 

Check out RR i think they had gen IH CPS for sale, they seen to have a good report.

 

Simon,
If it puts your mind at rest my CPS shat itself in wet weather
Not as COLD down in Canberra as in Cairns ,Maybe a case of water doing the CPS in
Then again you have gone another 400K"S so it might of been a hicupp
The wife has full confidence in the F250

Cheers,
Patchy

 

I've ordered some Ferrite Beads off flea-bay.

Research on US Bros forum tends to suggest:
1) Dodgy CPS - mine is a good CPS, OEM unit (Motorcraft blue, not the orig black) from RR;
2) bad earth - I'll have to lift the wiper cowl & take the dash off to check wiper motor earth and wiper switch (dash) earth contacts;
3) Interference - I will fit the Ferrite Beads (clip on type) over the CPS tail and tails around the wiper harness - the US theory is that electrical interference from the wiper motor causes the CPS signal to be 'lost' in transmission down the wire. The ferrite beads are supposed to suppress the interferance and allow the CPS signal to pass through.

 

Simon, do some research on these CPS units i have read they work good as well.

 

Simon , have you solved the CPS shorting problem ?
Did you find some ferrite chokes for the job , I've been talking to someone that had the same problem, they fitted five ferrite chokes all together and has solved his stalling.

 

Hi Blue, I got 10 TDK branded chokes off flea-bay. Now I just have to figure out the best place to put them.
It's not the CPS shorting as such, it is more the CPS connection wires acting like an antenna and picking up the electrical interference from the wiper motor causing the CPS signal pulse to be lost in the noise.
I'm going to put the chokes on the CPS wires, wiring to the wiper motor, and on a few other earth leads that I happen to uncover in my journey through the wiring.
When I get around to it I'll let you know how I go.

 

Some of the other guy's have put chokes on both wires to the cps and then all wires going to the wiper motor and then one large one over the whole loom , that has fixed there intermittent problem .

 

I've put a chock around the CPS wires, and some of the other earths that I found under the bonnet and behind the dash. I found a loose earth that may have been a contributing factor.

The photo is taken from under the truck - I've slipped off the serpentine belt, then compressed the split loom up and clipped on the grey coloured choke around the CPS wires directly above where the harness plugs into the CPS.

If I get a repeat of the problem I'll source some bigger chokes to put around the harness in the valley.