97 Cher Sport Check Eng Light Code 12
 

97 Cherokee Sport 170K auto 4wd

Keep getting a CEL code 12 (battery disconnected) error. Then it will go
away for a day, but it keeps coming back. 12 55.

Also, some times the auto trans will not shift into 4th gear. Presuming the
throttle position sensor here, but why no error on that? That symptom goes
away after restarting.

Only other flaky thing is the neutral safety switch. Always starts in
neutral, but not alw3ays in Park.

ANy ideas?

Re: 97 Cher Sport Check Eng Light Code 12
 

Rich D wrote:

> 97 Cherokee Sport 170K auto 4wd
>
> Keep getting a CEL code 12 (battery disconnected) error. Then it will go
> away for a day, but it keeps coming back. 12 55.
>
> Also, some times the auto trans will not shift into 4th gear. Presuming the
> throttle position sensor here, but why no error on that? That symptom goes
> away after restarting.
>
> Only other flaky thing is the neutral safety switch. Always starts in
> neutral, but not alw3ays in Park.
>
> ANy ideas?

Sounds like an open ground circuit to me. I've seen this happen on big
trucks; symptoms included PCM errors, intermittant starter failure, dim
lighting, sensor-to-ground failures, stuff like that. Check the
integrity of your negative battery cable, specifically where it bolts to
the frame and engine block.

Re: 97 Cher Sport Check Eng Light Code 12
 

Rich D wrote:

> 97 Cherokee Sport 170K auto 4wd
>
> Keep getting a CEL code 12 (battery disconnected) error. Then it will go
> away for a day, but it keeps coming back. 12 55.
>
> Also, some times the auto trans will not shift into 4th gear. Presuming the
> throttle position sensor here, but why no error on that? That symptom goes
> away after restarting.
>
> Only other flaky thing is the neutral safety switch. Always starts in
> neutral, but not alw3ays in Park.
>
> ANy ideas?

Sounds like an open ground circuit to me. I've seen this happen on big
trucks; symptoms included PCM errors, intermittant starter failure, dim
lighting, sensor-to-ground failures, stuff like that. Check the
integrity of your negative battery cable, specifically where it bolts to
the frame and engine block.

Re: 97 Cher Sport Check Eng Light Code 12
 

Rich D wrote:

> 97 Cherokee Sport 170K auto 4wd
>
> Keep getting a CEL code 12 (battery disconnected) error. Then it will go
> away for a day, but it keeps coming back. 12 55.
>
> Also, some times the auto trans will not shift into 4th gear. Presuming the
> throttle position sensor here, but why no error on that? That symptom goes
> away after restarting.
>
> Only other flaky thing is the neutral safety switch. Always starts in
> neutral, but not alw3ays in Park.
>
> ANy ideas?

Sounds like an open ground circuit to me. I've seen this happen on big
trucks; symptoms included PCM errors, intermittant starter failure, dim
lighting, sensor-to-ground failures, stuff like that. Check the
integrity of your negative battery cable, specifically where it bolts to
the frame and engine block.

Re: 97 Cher Sport Check Eng Light Code 12
 

Rich D wrote:
> 97 Cherokee Sport 170K auto 4wd
>
> Keep getting a CEL code 12 (battery disconnected) error. Then it
> will go away for a day, but it keeps coming back. 12 55.
>
> Also, some times the auto trans will not shift into 4th gear. Presuming the throttle position sensor here, but why no error on
> that? That symptom goes away after restarting.

Something is confusing the computer and putting things in limp mode.

> Only other flaky thing is the neutral safety switch. Always starts in
> neutral, but not alw3ays in Park.

The NSS is high on the transmission and a real bugger to get at.
It might need replacement or the harness might have been damaged
somehow.

> ANy ideas?

Always. ^_^

Check your battery terminals and cables, they may be loose
or corroded. I've even seen loose battery terminals.

check the engine ground strap and examine all the wire looms
and runs for any snags or melts.

Assuming you have the I6, check the O2 sensor wire where
it runs along the oil pan and is held to the block with a
clamp. If the shield has melted it can short out and cause
all sorts of problems.

--
DougW

Re: 97 Cher Sport Check Eng Light Code 12
 

Rich D wrote:
> 97 Cherokee Sport 170K auto 4wd
>
> Keep getting a CEL code 12 (battery disconnected) error. Then it
> will go away for a day, but it keeps coming back. 12 55.
>
> Also, some times the auto trans will not shift into 4th gear. Presuming the throttle position sensor here, but why no error on
> that? That symptom goes away after restarting.

Something is confusing the computer and putting things in limp mode.

> Only other flaky thing is the neutral safety switch. Always starts in
> neutral, but not alw3ays in Park.

The NSS is high on the transmission and a real bugger to get at.
It might need replacement or the harness might have been damaged
somehow.

> ANy ideas?

Always. ^_^

Check your battery terminals and cables, they may be loose
or corroded. I've even seen loose battery terminals.

check the engine ground strap and examine all the wire looms
and runs for any snags or melts.

Assuming you have the I6, check the O2 sensor wire where
it runs along the oil pan and is held to the block with a
clamp. If the shield has melted it can short out and cause
all sorts of problems.

--
DougW

Re: 97 Cher Sport Check Eng Light Code 12
 

Rich D wrote:
> 97 Cherokee Sport 170K auto 4wd
>
> Keep getting a CEL code 12 (battery disconnected) error. Then it
> will go away for a day, but it keeps coming back. 12 55.
>
> Also, some times the auto trans will not shift into 4th gear. Presuming the throttle position sensor here, but why no error on
> that? That symptom goes away after restarting.

Something is confusing the computer and putting things in limp mode.

> Only other flaky thing is the neutral safety switch. Always starts in
> neutral, but not alw3ays in Park.

The NSS is high on the transmission and a real bugger to get at.
It might need replacement or the harness might have been damaged
somehow.

> ANy ideas?

Always. ^_^

Check your battery terminals and cables, they may be loose
or corroded. I've even seen loose battery terminals.

check the engine ground strap and examine all the wire looms
and runs for any snags or melts.

Assuming you have the I6, check the O2 sensor wire where
it runs along the oil pan and is held to the block with a
clamp. If the shield has melted it can short out and cause
all sorts of problems.

--
DougW

Re: 97 Cher Sport Check Eng Light Code 12
 

You (the group) might be on to something. The negative pole was fine -
clean and dry, but the poisitve pole, while looking clean, when I took it
off was moist. Probably wicked up from one of those anti-corrosive pads
insatlled with the battery 2 years ago.

So far (12 hours) the CEL is off.

"DougW" <post.replies@invalid.address> wrote in message
news:ZObYg.35077$iA5.14705@dukeread11...
> Rich D wrote:
>> 97 Cherokee Sport 170K auto 4wd
>>
>> Keep getting a CEL code 12 (battery disconnected) error. Then it
>> will go away for a day, but it keeps coming back. 12 55.
>>
>> Also, some times the auto trans will not shift into 4th gear. Presuming
>> the throttle position sensor here, but why no error on
>> that? That symptom goes away after restarting.
>
> Something is confusing the computer and putting things in limp mode.
>
>> Only other flaky thing is the neutral safety switch. Always starts in
>> neutral, but not alw3ays in Park.
>
> The NSS is high on the transmission and a real bugger to get at.
> It might need replacement or the harness might have been damaged
> somehow.
>
>> ANy ideas?
>
> Always. ^_^
>
> Check your battery terminals and cables, they may be loose
> or corroded. I've even seen loose battery terminals.
>
> check the engine ground strap and examine all the wire looms
> and runs for any snags or melts.
>
> Assuming you have the I6, check the O2 sensor wire where
> it runs along the oil pan and is held to the block with a
> clamp. If the shield has melted it can short out and cause
> all sorts of problems.
>
> --
> DougW
>

Re: 97 Cher Sport Check Eng Light Code 12
 

Spoke too soon. The CEL is back on with a Code 45 now attached. Can't even
find a ref for that. Going to go get the OBDi checked for the real codes.

"Rich D" <brainiax@hvc.rr.com> wrote in message
news:bz8Yg.3377$Ct3.3301@news-wrt-01.rdc-nyc.rr.com...
> 97 Cherokee Sport 170K auto 4wd
>
> Keep getting a CEL code 12 (battery disconnected) error. Then it will go
> away for a day, but it keeps coming back. 12 55.
>
> Also, some times the auto trans will not shift into 4th gear. Presuming
> the throttle position sensor here, but why no error on that? That symptom
> goes away after restarting.
>
> Only other flaky thing is the neutral safety switch. Always starts in
> neutral, but not alw3ays in Park.
>
> ANy ideas?
>

Re: 97 Cher Sport Check Eng Light Code 12
 

You (the group) might be on to something. The negative pole was fine -
clean and dry, but the poisitve pole, while looking clean, when I took it
off was moist. Probably wicked up from one of those anti-corrosive pads
insatlled with the battery 2 years ago.

So far (12 hours) the CEL is off.

"DougW" <post.replies@invalid.address> wrote in message
news:ZObYg.35077$iA5.14705@dukeread11...
> Rich D wrote:
>> 97 Cherokee Sport 170K auto 4wd
>>
>> Keep getting a CEL code 12 (battery disconnected) error. Then it
>> will go away for a day, but it keeps coming back. 12 55.
>>
>> Also, some times the auto trans will not shift into 4th gear. Presuming
>> the throttle position sensor here, but why no error on
>> that? That symptom goes away after restarting.
>
> Something is confusing the computer and putting things in limp mode.
>
>> Only other flaky thing is the neutral safety switch. Always starts in
>> neutral, but not alw3ays in Park.
>
> The NSS is high on the transmission and a real bugger to get at.
> It might need replacement or the harness might have been damaged
> somehow.
>
>> ANy ideas?
>
> Always. ^_^
>
> Check your battery terminals and cables, they may be loose
> or corroded. I've even seen loose battery terminals.
>
> check the engine ground strap and examine all the wire looms
> and runs for any snags or melts.
>
> Assuming you have the I6, check the O2 sensor wire where
> it runs along the oil pan and is held to the block with a
> clamp. If the shield has melted it can short out and cause
> all sorts of problems.
>
> --
> DougW
>