Can you please explane the process for resetting the evap monitor following system repair
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2004 Jeep Grand Cherokee Question: drive cycle
Answer #1mastertech154 November 01, 2009, 14:31Journeyman
EVAP LDP MONITOR DRIVE CYCLE INSTRUCTIONS
Do not turn off the ignition switch during the test procedure.
All Onboard System Readiness codes are cleared if the battery is disconnected or when the Powertrain Control Module (PCM) is cleared with the scan tool.
This drive cycle can be used to determine if the Readiness code for this Monitor will run and complete, and if the Malfunction Indicator Lamp (MIL) will remain off after the vehicle is driven.
Operating Ranges: Whenever a range of values is provided, try to operate the vehicle in the middle of the range. For example, if the vehicle speed range is from 45-65 MPH, operate the vehicle at as close as possible to 55 mph. If the Short Term fuel trim range is -20% to +20%; try to operate the vehicle near 0%.
Scan Tool Data: There are certain Parameter Identification (PID) values that must be within range before this Monitor will "run". It can be helpful to pull up those PID items on the scan tool so an assistant can view them during the test.
This information is a representation of a Drive Cycle, and may vary due to software revisions to the PCM.
EVAP LEAK DETECTION PUMP (LDP) MONITOR PRETEST CONDITIONS
Cold engine startup (requires a key-off period of 8-10 hours).
MIL is off.
No emission related diagnostic trouble codes (DTC's) are present.
Ambient temperature between 40-90ºF at startup.
BARO signal range from 22.1-31.0" Hg.
BTS signal range between 21-130ºF at startup.
ECT signal within 18ºF of the BTS signal at startup.
Fuel level between 15-85%.
EVAP LEAK DETECTION PUMP (LDP) MONITOR ENABLING CONDITIONS
Battery voltage range from 10.5-15.5v.
Vacuum range from 4.9-31.0" Hg.
Vehicle speed from 0-10 MPH.
Connect the scan tool to the data link connector (DLC), and bring up the Readiness code for the EVAP Leak Detection Pump (LDP) Monitor.
Engine started (cold) with the BTS signal between 21-130ºF.
Accelerate at part-throttle to a speed of 0-10 mph and maintain that steady speed for several minutes. Bring the vehicle to a stop in a safe place, but do not turn off the ignition key.
Check the status of the Readiness code for the EVAP LDP Monitor. It should change to YES or COMPLETE when the test is done. If it does, return to the service bay and turn off the ignition key. If it does not, check for any temporary codes. If no temporary codes are set, return to step 1 and repeat the test procedure.
HELLO , IF YOU MADE YOUR REPAIRS AND HINK THAT THE VEHICLE IS FIXED , JUST CLEAR THE CODES FROM THE COMPUTER AND DRIVE THE VEHICHLE AS YOU NORMALLY DO , IF THE REPAIRS DID NOT FIX THE CAR , THEN THE COMPUTER WILL TURN BACK ON THE CHECK ENGINE LIGHT , IF THE SAME CODE IS PRESENT THEN YOU HAVE ANOTHER ISSUE
Answer #2Visitor, December 17, 2010, 12:03
What are the steps to reset the drive cycle in a 2003 Jeep Grand Cherokee Laredo