Mondeo Electrical Fault
I have a Mondeo 03 tdci which I am having problems with.
The battery light came on and I lost all power so took to mechanic who fitted a new alternator but the battery light stayed on.
Mechanic diagnosed a faulty lead from altrnator to battery, so replaced this and battery is now charging but battery light is still on.
Can anyone suggest anything?
I had a diagnosis check which came back with 'P1632 smart alternator faults sensor circuit malfunction'
What does this mean and how do I fix?
ANy help much appreciated. The car is also running a bit rough causing odd vibrations
The car has Ford's smart charge system. The battery charge is controlled by the computer in the car.
Has the car got the right type of battery fitted? It cannot be fitted with the ordinary type, must be silver calcium. It cannot be charged on the car with an ordinary battery charger and you cannot use jump leads or booster pack - well you can but....
You will need to take it to Ford to reset the system.
There have been problems with the plug, which has 3 small wires, breaking at the alternator.
Also, there is a temperature sensor for the battery and this may be faulty.
Last edited by Hometune; 23-10-08 at 13:20.
Thanks for that...
The battery has been on since I got the car and I haven't had a problem with it.
I have now charged it with a normal battery charger and also had it jumped a couple of times (once by a RAC patrol).
Spoke to Ford about reseting the smart charge system but they don't think this will cure the problem.
it's £40 to try it anyway.
Surprised the RAC jump started it as there is a warning about this. The system can allow 18v and can do serious damage.
Incidentally, a faulty battery can cause this problem.
Yeah, the rac man jump started it with his power pack then I drove home with the pack still connected cos my battery was totally dead and not charging.
What sort of serious damage do you mean?
My mechanic assues me the battery is ok
I think that you definitely need to go to Ford to sort this.
There are several checks that need to be done on the 3 wire connector(smart charge) at the alternator. You can disconnect this plug and see if there is 14v now going to the battery as it will revert to an ordinary system.
Your car is designed to run on about 14.5v max so 18v can cause damage to components.
I'd be very surprised if you don't have to replace the battery now. With respect, your mechanic does not fully understand this system.
Here is the text from an auto-electrical spe******t:
A faulty battery can cause this type of fault
the battery must be Silver Calcium a standard battery will not work with smart charge system
when you remove the smart charge 3 pin plug from the back of the alternator it reverts to a conventional alternator if you do not about 13.8/14.0 volts carry out basic charging system checks and suspect the alternator its not a smart charge fault.
you will need a scope to check the smart charge system
Pin 1 ... Alternator Feedback
Pin 2 ... Alternator Load Request FROM ECU
Pin 3 ... Reference Voltage 12 VOLTS +
pin3 must be the same as the battery voltage it is fed from a fuse in the CJB Central Junction box (fuse box) and a high resistance on the fuse contacts causes a volt drop and the smart charge voltage will drop out
Next pin 1 & 2 need checking back to the PCM for resistance, isolation from ground and each other If is ok test with the your scope at Pin 2 is the request from the PCM to the alternator this will be a square wave pattern that will change with load request So lights and heated screen etc.. on and monitor for a change in the pattern
No change in the pattern means no request from the PCM looks like a PCM ECU fault if the pattern dose charge when testing the load voltage the Pin 1 is the feedback from the alternator and MUST remain a constant square wave pattern if this pattern is the same as the one on pin 2 the smart charge part of the alternator is faulty test and change the alternator
PLEASE NOTE NEVER JUMP START THIS TYPE OF SYSTEM WHEN THE BATTERY IS COMPLETE FLAT THIS TYPE OF SYSTEM CAN PRODUCE OVER 18 VOLTS WHEN IT FAILS
Last edited by Hometune; 23-10-08 at 14:48.
I'll let you know the outcome
I have the same problem (GhiaX Est 130TDCi 130 54plate) . I took it to Ford and they said the battery and alternator are good and suspected a faulty smartcharge loom or ECU...mega bucks and so they said ignore it, with the smartcharge cable disconnected the battery charges as normal 14v which is OK
However, I'm suspecting a cable break in the smart charge cable as I noticed the 7.5A fuse in the engine compartment has blown. I replaced it and the battery light intially was off but then it blew the fuse and came back on ,,with or without the smart charge cable connected to the alternator it still blows the fuse.
I understand the smart cabling to the alternator needs to be cut back and a brake or abbrasion is often found 4-6inches from the connector often the blue or grey cable is suspected. Any other suggestions appreciated. And an explanation why the fuse blows. All other fuses in both boxes are good.
You can buy a short length of modified loom that replaces the existing loom to the alternator. Costs around £11+vat from Ford.
This is for broken wires which are very common on all Fords with this system. A fuse blowing is a direct short which points towards a live broken wire touching earth.
Checked the loom last night and followed the wiring up to first block connector right againt engine block on left hand sidea Found problem wire which had burnt through plastic coating and exposed wires shorting on engine block ! Had obviously been a previous problem as a different type of fuse had orginally been replaced in the fusebox & the wire had been heavily taped up before but tape slid down to reveal exposed wire. Retapped it, replaced fuse and light finally is off and stayed off. THe heated from Windscreen which we thought wasn't working as the button wasn't lit is now lit and working too so good fix all round !!At last !!