Check Engine Light - Code P0340 & B1676

1999 Ford Explorer XLT 5.0L 302cu.in. V8 AWD

Truck seems to run fine, was having hard start issues before the fuel pump went out but doesn't seem as bad now that the fuel pump has been replaced?

I noticed what sounded like a belt squeal during take off or acceleration about a week or two ago, it was sporadic, and I didn't think too much of it since I had just replaced the serpentine belt a couple of months ago when I replaced the passenger side exhaust manifold (On a side note I had to replace the fuel pump last month and did the filter too at the same time.). Now a couple of days ago my check engine light came on and I was right by an Autozone so I stopped in and had them run a diagnostic code scan for me. It found two codes, a B1676 which said it was "battery pack voltage out of range" and a P0340 which he said he would have to look up inside the store to figure out what it meant. He looked it up and said it was the cam sensor and it needed replaced. I told him I would hold off till payday, not that I needed to I really just wanted to do more research to make sure it was the right diagnosis.

So there is the story, I looked online and read about the Camshaft synchronizer causing a squeal and when they do they usually have destroyed the cam sensor at the same time too, that's why when you buy the synchronizer you get the sensor too as a complete assembly.

Question? Can I just unscrew and pull the sensor off(just the black cap, not the synchro) and inspect it and just screw it back on without any problem? In other words still be able to drive it after I pull it off to check it out, it won't throw timing off or I won't need to do anything special when I put it back on will I?

Also how does the B1676 code fit in? The code B1676 is related to the ABS system from what I have found. The ABS light has come on and gone off multiple times in the last 5 or so years? The light goes off when the truck has been shut off then restarted

I did have to use a battery charger to start the truck a few times this winter and the battery is about 6 years old. I am wondering if that could be the issue from what I have read both those codes can stem from a weak battery?

http://www.engine-codes.com/B1676.html

there's an alignment tool you can borrow from AutoZone to help you install the camshaft synchronizer. I think there's a grey colored one and a black one (depending on your model year). I've heard it can be done w/out it, but I won't risk it. if you search the forum, you'll find threads on this subject (example below).

http://www.explorerforum.com/forums/showthread.php?t=89670

I don't see what one problem would have to do with the other.

On the 2 wire cam sensors used from 99-up, there has been issues of cam sensor codes displayed, but the cause was a "dirty" alternator-voltage regulator. This makes me wonder if the bad cam sensor signal might have tripped the charge fault code?

You can pull the sensor cap off for a look. Use a 4.5mm socket on a swivel and a long 1/4" drive extension. It is keyed to go back in the very same position.

The housing is the piece that needs to be "timed" with the tool.

Good luck. I'd like to know what you find in there. You might take a couple of pictures for us.

Turdle said:

On the 2 wire cam sensors used from 99-up, there has been issues of cam sensor codes displayed, but the cause was a "dirty" alternator-voltage regulator. This makes me wonder if the bad cam sensor signal might have tripped the charge fault code?

Click to expand...

What part is that? and what do you mean by dirty? As in I need to clean it or the connections or that it is producing what is sometimes referred to as a dirty current of electricity?

Turdle said:

You can pull the sensor cap off for a look. Use a 4.5mm socket on a swivel and a long 1/4" drive extension. It is keyed to go back in the very same position. The housing is the piece that needs to be "timed" with the tool.

Click to expand...

Ok I will be pulling it off today then. Thank you for the bolt head size! I didn't want to pull the housing/synchronizer, and that is what I thought(it needing the tool to reinsert it).

Turdle said:

Good luck. I'd like to know what you find in there. You might take a couple of pictures for us.

Click to expand...

I will take a couple of pics and post them, Thanks for the help!

I was merely reaching for a connection between the 2 trouble codes. By "dirty" I meant a bad or noisy signal from the alternator. This has been documented to cause a cam sensor fault code.

If the cam sensor checks out, then look at the alternator. Both parts might squeak when going bad.

Just had O'Reilly's run a check on the battery and the alternator. They both tested good. So now it's time to pull the camshaft sensor off and inspect it.

Ughh, it is snowing heavy and 10 degrees outside, looks like this will have to wait till the weather eases up a bit..........

Today was the day!!!

40 degrees outside......15-20 mph winds......slushy wet snow on the ground......
wahh wahhh wahhh

Member Turdle saved me a massive headache by teaching me a method of finding TDC without pulling the #1 spark plug or having to look at the marks on the harmonic balancer/crank pulley.

Here's how it worked:

Remove battery ground for safety.

Unplug the sensor and remove two 5.5mm bolts to remove old sensor off the synchronizer that's going to be replaced, before removing the sychronizer, turn the motor with a 1/2" drive wratchet-24mm deep well socket on the crankshaft bolt until the alignment tool fits on the sychronizer(that is when the tab that spins is in the center of the cutout on the synchronizer housing), mark position on engine(the arrow on the alignment tool on mine straight toward the front bumper), now if the alignment tool sits flush on the old synchronizer then you are now at TDC and can remove the ratchet from the crankshaft bolt(I did it from underneath the truck) and DO NOT TURN THE MOTOR, leave the alignment tool on until it is being removed from the truck, here I had to remove the three nuts that held the coil pack bracket(one on each side and one in back, easy to get to with 3/8" ratchet, long extension, swivel/universal, and 12mm or 1/2" socket) and one nut on the left side that held the throttle cable bracket, unplug the coil packs( small screwdriver to spread clips on each side) so you can lift the bracket up, then loosen/remove the hold down bolt(3/8" ratchet, long extension, swivel/universal, and 12mm or 1/2" socket) and remove the old synchronizer(here I had to take the alignment tool off and it took some maneuvering to find a spot to get it out from under the coil pack bracket, be patient and remember how it came out so you can put it back in the same way in reverse), lube the new synchronizer(5 or 10w 30or40 is fine, put some on the O-rings,the gear, the shaft and in the hole on the end of the shaft), put the alignment tool on(DO NOT TAKE IT OFF) and drop it in so it sits just like the original one did(mine had the arrow on the alignment tool facing straight toward me/the front bumper, if you have to pull it out and turn it and try again until it is just like it was when you pulled the old one out) and lines up with the mark you made(LEAVE THE TOOL ON), replace hold down bolt, NOW remove alignment tool, install new sensor, plug in electrical and reinstall the coil pack bracket nuts and plugs, reattach any wires to the bracket you may have had to remove to get it up high enough to get the synchronizer out.


My old sychronizer still had the metal tab and looked ok, but it was hard to turn. And I still have the chirping noise???? Maybe the belt tensioner? And the check engine light did go off!! So I have that going for me........

Thank you Turdle! It wouldn't have been as easy without that trick!