check engine on, but no codes.

4x4 XJ

NAXJA Forum User

Location

Carson, CA

• Jun 2, 2015

• #1

I have a 99 XJ manual tranny 4.0L engine.

So the check engine is on with no codes. When I try erasing the codes while the engine is running I can't do it. But if I have the key on ACC position I can erase the CEL, but it comes back on the next time I start the car.
Today I was able to pull code P0443, when I ran a second scan it came back as no codes.
I swap the purge solenoid with another one and CEL still on. I checked all the vacuum lines on the engine and all the way back to charcol canister and no cracks.


Anyone have any idea what the problem could be.. i need the CEL off to have it smogged.
Thank you

 

Last edited: Jun 3, 2015

L

Luke95

NAXJA Forum User

Location

CT

• Jun 2, 2015

• #2

Did you open the hood to make sure the engine is still there?

My xj does this pulling the battery cables and holding them together resets it normally.

 

4x4 XJ

NAXJA Forum User

Location

Carson, CA

• Jun 3, 2015

• #3

Yes I drive the xj all the time..
I disconnected the batt for 15 min and nothing...

 

Last edited: Jun 3, 2015

J

Jays siik xj

NAXJA Forum User

Location

Redlands/Highland

• Jun 3, 2015

• #4

Gas cap.... its always the gas cap. hahaha

 

sidewaysstarion

Coffee Drinker

NAXJA Member

Location

Torrance, CA

• Jun 3, 2015

• #5

If you're up for a drive, you can cruise over here to Torrance, I have 2 spare ecus (auto but I can fix that) and a fancy code reader.

 

4x4 XJ

NAXJA Forum User

Location

Carson, CA

• Jun 3, 2015

• #6

sidewaysstarion said:

If you're up for a drive, you can cruise over here to Torrance, I have 2 spare ecus (auto but I can fix that) and a fancy code reader.

Click to expand...

When are you available.

 

sidewaysstarion

Coffee Drinker

NAXJA Member

Location

Torrance, CA

• Jun 3, 2015

• #7

Tomorrow and Thursday after 4pm and most of the day Sunday.

 

4x4 XJ

NAXJA Forum User

Location

Carson, CA

• Jun 3, 2015

• #8

Also I just checked my jeep and it has not LDP, I am guessing I have a federal emissions jeep???

 

JohnX

Sarge

NAXJA Member

Location

Williams AZ

• Jun 3, 2015

• #9

Underhood sticker will tell you its compliance to state or federal.

 

4x4 XJ

NAXJA Forum User

Location

Carson, CA

• Jun 3, 2015

• #10

Yup just saw the sticker is a Federal....

 

ParadiseXJ

NAXJA Forum User

Location

Paradise, CA 95969

• Jun 4, 2015

• #11

Did you investigate the code you pulled? EVAP purge solenoid? Number 2 in this diagram. Google it.

I had a Nissan with a persistent code that neither me nor my mechanic could pin down. I repaired (replaced the supposed part) it, but the code kept coming back. Every 40-50 miles it would reset and pop on. A real pisser. I replaced the ECU, code went away...forever. It's worth trying to run down the cause of the code...but if that fails maybe the computer is lying. Good luck.

 

sidewaysstarion

Coffee Drinker

NAXJA Member

Location

Torrance, CA

• Jun 5, 2015

• #12

Last night I met up with 4x4 XJ and hooked up my DRB, I found the P0443. I ran an EVAP activation test, found the solenoid didn't buzz. I swapped it with a known good solenoid, still no buzzing. Swapping the ECU for a known good one, still no buzz. I checked the connector and found the EVAP solenoid had no power. We replaced fuse #10 in the kick panel and now the EVAP solenoid works and the code shouldn't come back.

I also married his keyfob to his RKE while I had the DRB out.

 

O

Owenclemmons

NAXJA Forum User

Location

Sunnyvale

• Sep 7, 2019

• #13

Dude - just wanted to say thanks I had the same problem and it turned out to be the fuse. Was almost pulling out my hair before I found this post.