Comments on: OBD Codes

By: Chris

Chris — Sat, 04 Apr 2009 18:18:47 +0000

I have the same problem 000-999, but than no code. Autozone said “303″ misfire in cyl #3, and gave me a list of possibilities, but it’s still cool to know that my Jeep can diagnoes it’s self. In theory.

By: Head Mechanic

Head Mechanic — Fri, 27 Mar 2009 05:58:34 +0000

I think if your still having problems with the methods here, if you have an Autozone or auto parts store they should be able to scan the codes for free through the diagnostic port. That will give you plain answers quickly.

By: Andrea

Andrea — Mon, 23 Mar 2009 13:56:25 +0000

Thanks for the info. Alas, I tried both the methods you suggest on my 1998 Cherokee but neither works: the on-off method simply doesn’t do anything; with the Trip Reset button method I see the odometer counting from 000000 to 999999 while the lights and gauges do fancy stuff, but after 999999 I just see the current mileage, and the Check Engine light is on. Am I missing something?

By: Head Mechanic

Head Mechanic — Sat, 21 Feb 2009 22:22:51 +0000

Rob-

With the 3 codes your getting, it sounds like this Jeep has been in an accident.
340 No camshaft signal being received by the computer
1388 Auto shutdown relay circuit problems?
1389 No Z1 or Z2 voltage seen by the computer when the auto shutdown relay is used.

The camshaft signal could be a simple sensor bad or unplugged. This is located at the front of the motor. The other 2 lead me to believe it has a issue with trying to save itself. The auto shutdown is usually a “rollover” sensor to cut all power to fuel and spark in the event it becomes a turtle.

If you have more details about the rig, let me know. I’m curious if you get power to the dash, accessories, dome light, etc.

By: Rob

Rob — Sat, 21 Feb 2009 21:23:59 +0000

Hi i have a jeep grand cherokee limitted 4.7L
and it will not start, so i checked the codes and it gave me p0340-p1388-p1389, so how can i fix this problam, dont tell me to go to a dealer they just make it worse.

By: Ned

Ned — Thu, 26 Jun 2008 20:44:52 +0000

I have 04 Grand Cherokee and error codes are P1489 and P1490. What could be causing it. Car does not idle.

By: tony

tony — Sat, 17 May 2008 18:45:41 +0000

Hello, I have a 2005 Jeep Wrangler 4.0 ltr the code reads P0112 Air IntakeTemperature Sensor below normal voltage. Should i just replace the sensor or are there other issues?

Thanks

By: admin

admin — Fri, 25 Apr 2008 20:20:43 +0000

Dan-

Sounds like you have a bad injector which is causing the misfire. Both are coming from #5 cylinder. I would start with inspecting the injector. See if it’s leaking or has a bad wiring connection at the harness. If both of those seem good, try to locate another injector to swap out in the testing (NAXJA or NAGCA websites). Injectors can and do fail sometimes. Remember to clear your codes when swapping another injector in.

By: Dan Hatt

Dan Hatt — Fri, 25 Apr 2008 19:50:12 +0000

Hi,I have a 03 Grand Cherokee with the 4.0L and it is listing both a 205 and 305 code.How’d you fix your’s?????