Bought Grand Cherokee. Have a few problems. - Page 2 -
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > Bought Grand Cherokee. Have a few problems.

Win this 2015 Jeep !!The Morris 4x4 Center Holiday Gift ShopSuperchips Tuning Products - 10% 0ff INSTANTLY!!

Unread 12-31-2003, 07:26 AM   #16
Registered User
Join Date: Dec 2003
Posts: 94
Originally Posted by RockPaws
If its neither the IAC or TPS, I would take it some where and have the computer checked. I do not like throwing parts at a problem to see what fixes it. (we call it "Shotgun Maintenance").

Here is what the PCM looks at idle mode, at operating temp (closed loop). Inputs to the PCM:
1) A/C select signal
2) A/C request signal
3) Battery voltage
4) Crankshaft position sensor
5) Eng coolant temp sensor
6) Intake manifold air temp sensor
7) Manifold absolute pressure (MAP) sensor
8) TPS - throttle pos sensor
9) Camshaft position sensor (is distributor)
10) Park/neutral switch
11) O2 sensors
Based on these inputs - voltage is applied to the fuel injectors with the ASD relay via the PCM. The PCM wil them control injection sequence and injector pulse width by turning on and off voltage to each injector, thru its ground circuit.

The PCM monitors the O2 sensorsinput and adjusts air fuel ratio by injector pulse width. It also adjs eng idle speed thru the idle air control (IAC motor).
The PCM also adjs ignition timing by inc or dec spark advance.
Well I would rater place a couple sensors that are at 118,000 miles then adjust the idle least yet. I do know that should all be controlled with the computer that rec. the data from the if there is a bad sensor it is sending faulty data to the computer which in turn is not letting it adle correctly. I already bought the TPS sensor so I will replace it then I will take it to a stealership so they can charge me $50 to put there comptuer on it.


rollerbones is offline   Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools

Suggested Threads

Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. is not in any way associated with Jeep or the Chrysler Corp.