2000 XJ throwing a code

XJumpmaster · Jan 10, 2009

Hey OEM Gods,
My 2000 XJ started throwing a code yesterday.

P 1493 : Ambient/battery temp sensor input voltage too low.

My questions are:

Where the hell is this sensor located? How hard is it to fix? Is there a work around for this?(answer this last one via PM please)

Of course Murphy is firmly camped out at my place as my inspestions are due this month.:twak: My electronic copy of the FSM is not complete and does not include section 8A.

Help a brother out!

Josh

McQue · Jan 10, 2009

Well, the sensor should be under the battery, mounted to your battery tray/box...

Check it out...maybe sensor is bad or loose connection...bad wire....

lazyxj · Jan 10, 2009

XJumpmaster said:
Hey OEM Gods,
My 2000 XJ started throwing a code yesterday.
P 1493 : Ambient/battery temp sensor input voltage too low.
My questions are:
Where the hell is this sensor located? How hard is it to fix? Is there a work around for this?(answer this last one via PM please)

The sensor is located in the bottom of the battery tray. It looks like a round button with the wires coming out from under it.
Before replacing it, check for a bad connection or broken wire. I have found that most of my electrical problems have been due to poor connections.
Dielectric grease is your friend.

I have no idea how to bypass it.

winterbeater · Jan 10, 2009

2000 FSM says that sensor has 5 volt input from PCM. So if you check with voltmeter at plug to sensor under battery, you should get 5 volts. Sounds like it's not the sensor from that. It's probably the plug contact. I'd plug and unplug it a few times to scrape out the connection and see what happens. I guess that then you'd have to disconnect the battery to reset the codes? If you don't get 5 volts at the plug, trace the wire back to the PCM looking for other plugs or wire damage.

Extra info: As the battery temperature increases, the resistance decreases.

lazyxj · Jan 10, 2009

winterbeater said:
Extra info: As the battery temperature increases, the resistance decreases.

Any idea what the sensor's resistance range is?
If the sensor is defective, it might be possible to fool the ECM by replacing the battery sensor with the appropriate sized resistor.

garr · Jan 10, 2009

P 1493 : Ambient/battery temp sensor input voltage too low.

That code used to come up on a buddy of mine's Jeep when it was extremely cold out (Below "0").
Why, I have no Idea!!

birchlakeXJ · Jan 10, 2009

Doesn't come up a lot but when it does, if memory serves me correctly, it's generally a plug/contact issue.

As mentioned before, check that and use dielectric grease.

XJumpmaster · Jan 10, 2009

Thanks all for the quick responses. I will pull the battery tonight and check it out. Unfortunately, I have already purchased a replacement as it a stealer only item or special order from Checker. It's only $50. I just didn't know where it was located. I couldn't see it from up top.

Thanks, again,

Josh

winterbeater · Jan 11, 2009

lazyxj said:
Any idea what the sensor's resistance range is?
If the sensor is defective, it might be possible to fool the ECM by replacing the battery sensor with the appropriate sized resistor.

Yeah, you could, but that info is not in FSM. So, no I don't know.

winterbeater · Jan 11, 2009

Sorry, can't resist preaching about this for electircal problems:

90% connections, but everyone keeps throwing parts on their Heeps! And the scariest thing is that the parts they put on are probably not as good as the one's that were put on in the factory. The used car I don't want to buy is the one "with many new parts".

:soapbox:

2000 XJ throwing a code

XJumpmaster

NAXJA Forum User

McQue

NAXJA Forum User

lazyxj

NAXJA Member #1310

winterbeater

NAXJA Forum User

lazyxj

NAXJA Member #1310

garr

NAXJA Forum User

birchlakeXJ

NAXJA Forum User

XJumpmaster

NAXJA Forum User

winterbeater

NAXJA Forum User

winterbeater

NAXJA Forum User

Similar threads