Bad Computer?
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Junior Member
Joined: Jul 2013
Posts: 44
Likes: 1
Model: Cherokee
Bad Computer?
Can Some one please help me with this situatuion? Keep getting the same codes. This is the information I got from some OBD software I just got.
1. Using a scan tool, command the purge solenoid to activate. Listen or feel for a clicking coming from the purge solenoid. It should click once, or on some models it may click repeatedly.
2. If it doesn't click with scan tool activation, unplug the connector and examing the solenoid and connector for damage, water, etc. Then check for battery voltage on the feed wire with the key on. If you have battery voltage, then ground the control side manually using a jumper wire and see if the valve clicks. If it does, then you know the solenoid is working properly but there is a problem with the control circuit. If it doesn't click when you manually ground it, replace the purge solenoid.
3. To check for a problem on the control circuit (if the solenoid tests okay and you have voltage to the solenoid) plug the solenoid back in and remove the control circuit (ground) wire from the ECM connector (If you're unsure how to do this, do not attempt). With the ground wire removed from the ECM, turn the key on and then manually ground the Purge valve control wire. The solenoid should click. If it does, then you know there is no problem with the control wire to the solenoid and there is a problem with the ECM purge solenoid driver circuit in the ECM. You'll need a new ECM. However if it doesn't click, then there must be an open in the wiring between the ECM and and the solenoid. You must find it and repair it.
Just need some help with the wiers to check. Cant find any usefull diagrams online.
PS Just replaced the purge solinoid and leak detection pump.
Thanks
Chris
1. Using a scan tool, command the purge solenoid to activate. Listen or feel for a clicking coming from the purge solenoid. It should click once, or on some models it may click repeatedly.
2. If it doesn't click with scan tool activation, unplug the connector and examing the solenoid and connector for damage, water, etc. Then check for battery voltage on the feed wire with the key on. If you have battery voltage, then ground the control side manually using a jumper wire and see if the valve clicks. If it does, then you know the solenoid is working properly but there is a problem with the control circuit. If it doesn't click when you manually ground it, replace the purge solenoid.
3. To check for a problem on the control circuit (if the solenoid tests okay and you have voltage to the solenoid) plug the solenoid back in and remove the control circuit (ground) wire from the ECM connector (If you're unsure how to do this, do not attempt). With the ground wire removed from the ECM, turn the key on and then manually ground the Purge valve control wire. The solenoid should click. If it does, then you know there is no problem with the control wire to the solenoid and there is a problem with the ECM purge solenoid driver circuit in the ECM. You'll need a new ECM. However if it doesn't click, then there must be an open in the wiring between the ECM and and the solenoid. You must find it and repair it.
Just need some help with the wiers to check. Cant find any usefull diagrams online.
PS Just replaced the purge solinoid and leak detection pump.
Thanks
Chris
Last edited by scatgo; Mar 18, 2015 at 05:59 PM.
Thread Starter
Junior Member
Joined: Jul 2013
Posts: 44
Likes: 1
Model: Cherokee
Info is in my signature. Codes are PO443 Evaporative Emission System Purge Control Valve Circuit PO302 Cylinder 2 Misfire Detected PO700 Transmission Control System PO463 Fuel Level Sensor "A" Circuit High
P1495 - Chrysler Type Powertrain - Manufacturer Controlled DTC - Manufacturer Controlled
Description EVAP LDP Solenoid Circuit Conditions
Cause Cold engine startup requirement
It runs great. Never feel a miss fire.
P1495 - Chrysler Type Powertrain - Manufacturer Controlled DTC - Manufacturer Controlled
Description EVAP LDP Solenoid Circuit Conditions
Cause Cold engine startup requirement
It runs great. Never feel a miss fire.
CF Veteran
Joined: Feb 2010
Posts: 12,367
Likes: 23
From: Oroville, CA
Year: 1995
Model: Grand Cherokee
Engine: 4.0 with all of the noise and clatter
Not everybody can see signatures depending on what device is used to see the site.
Have you cleared the codes and see which ones pop up again?
Have you cleared the codes and see which ones pop up again?
Last edited by Bustedback; Mar 18, 2015 at 07:48 PM.
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