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code P1633

11K views 13 replies 3 participants last post by  cosworth  
#1 ·
Code P1633 comes up as KAM voltage too low. Apparently when the brain detects less than 9v it throws this code.

Battery has been greased up with dielectric grease as well as the brain connectors under the pollen filter. Everything is dry and clean.

Battery terminals read 13.7v when idling.

Stumped on this one. I'm usually pretty good at electric faults but I can;t determine this one. Since the voltage is spot on I don't suspect the alternator. Help? 2000 S 4.0 sport.
 
Discussion starter · #3 ·
Yeah I got the connectivity covered. The dieletric grease is smothered on.

The battery is of an unknown age. Bought the car a year ago and the voltage seems fine. Whomever installed it did not mark the little calendar on top of it. Dummy. Alternator it's not since it will chuck this code out with KOEO (key on engine off).

A battery is a $130 gamble but at this point I might take it. Multimeter says it's fine. I think the Jag electrics could be pretty fussy about the battery though.

I did have the alternator off in the spring to do the cam tensioners, but it's been doing this since may sporadically and now it's solid with the code reader unable to clear the code. A degrading battery fits the bill, but the voltage indicates otherwise.

Maybe I'll try Wal-Mart, buy a battery and if it's not the problem take it back and say it doesn't fit my car. Most places don't take battery returns though. Not cheap, I just don't see the value in having a perfectly good battery laying there.
 
Discussion starter · #5 ·
No dancing sadly, battery tested fine. Stumper.

I can see the bill at Jag now. 7 hours diag, no cause for fault found. Code not cleared and not repaired. $900 dollars please.
 
Discussion starter · #9 ·
The brain is behind the glove box. Appears to be a real bugger to get out. Removed the connectors requires removal of the wipers, the wiper cowl the the pollen filter/holder/trumpet then the 3 connectors are uncovered.

Now as far as I know, the battery is the actual main battery for KAM. I've never heard of a small ECU battery fitted like on a motherboard. Ever.
 
Discussion starter · #11 ·
I've noticed that the light is off when started, but the engine light come son after about 15-20 seconds after it has started.

13.7v idling, 12.2v first thing on the morning on the terminals.

Funny, can't find anything wrong with it.
 
Discussion starter · #12 ·
Well I tried a brand new battery. Still the code persists.

Interesting though, the new battery I guess was sitting on a shelf for some time. It was reading 10.3 volts. So I drove around a bit. If you turned off the engine for say 10 seconds then did a KOEO test the code would clear. KOER test, the code came back right away. After I charged it up to 12.5v after a 20 minute drive, the code would not clear at all (KOEO or KOER) and the idling voltage was the same at 13.7. that was weird.

At this point I think the PCM is dead. NOT a cheap fix.
 
Discussion starter · #14 ·
Ha!. Stealers reset the code for free on my oil change. Seems my little code reader can't kill off all codes successfully.

Jaguar/Land Rover of Richmond comes through. Saved me $200 for a new ECU that I didn't need.