Neon L4-2.0L SOHC (1995)
PROM - Programmable Read Only Memory: Customer Interest
PCM - MIL ON/IAC DTC Set
NO: 18-03-95
GROUP: Vehicle Performance
EFFECTIVE DATE: Feb. 3, 1995
SUBJECT:
Check Engine Light On "Vacuum Leak Found (IAC Fully Seated)"
MODELS:
1995 (PL) Neon
NOTE:
THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 2.0L SOHC ENGINE AND AUTOMATIC TRANSAXLE.
SYMPTOM/CONDITION:
Check Engine Light is on, Diagnostic Trouble Code "Vacuum Leak Found (IAC Fully Seated)".
DIAGNOSIS:
Using the Mopar Diagnostic System (MDS) or the Scan Tool (DRBIII) and appropriate Diagnostic Procedure Manual, verify that all engine systems are
functioning correctly. If Diagnostic Trouble Codes (DTC's) other than "Vacuum Leak Found (IAC Fully Seated)" are present, record them on the repair
order for future reference and repair as necessary.
NOTE:
THE IAC WILL BE FULLY SEATED ONLY WITH A GROSS VACUUM LEAK. THE DIAGNOSTIC ROUTINE IN THE PCM DOES NOT
USE IAC DATA IN SETTING THIS FAULT. IF THE IAC CONTROLS THE IDLE SPEED PROPERLY, DO NOT REPLACE IT.
Verify that a gross vacuum leak does not exist. With the engine at normal operating temperatures, transmission selector in neutral, using MDS and/or
DRBIII, the idle speed should not exceed the target value by more than 50 RPM for more than 10 seconds. If the idle speed is within this limit and only
the "Vacuum Leak Found (IAC fully Seated)" DTC is present, proceed with the following repair.
EQUIPMENT1PARTS REQUIRED:
1
CH6OOO
Scan Tool (DRBIII )
1
CH7035
General Purpose Interface Bus Cable (GPIB)
1
CH7OOO
J1962 Cable
1
4669020
Label - Authorized Software Update
1
4275086
Label - Authorized Modification
REPAIR PROCEDURE:
This bulletin involves selectively erasing and reprogramming the Powertrain Control Module with new software (calibration change).
NOTE:
MDS AND DRBIII ARE REQUIRED TO PERFORM THE FOLLOWING REPAIR. MDS MUST BE OPERATING WITH RELEASE 16 OR
HIGHER INSTALLED.
1.
Connect the MDS (Mopar Diagnostic System) and DRBIII (Scan Tool) to the vehicle and power them up.
2.
Use the arrow keys and select # 2 MDS DIAGNOSTICS on the DRBIII MAIN MENU Screen.
3.
Use the arrow keys and select DIAGNOSTIC MENU on the MDS, then press NEXT MENU.
4.
Use the arrow keys and select CONTROLLER PROGRAMMING on the MDS, then press NEXT MENU.
5.
Use the arrow keys and select PROGRAM CONTROLLER PART on the MDS, then press NEXT MENU.
6.
Follow the steps presented on the MDS and DRBIII which will allow the DRBIII to obtain the current part number of the controller.
7.
The MDS will display the part number of the controller on the vehicle and the appropriate replacement part number, then press NEXT MENU to
begin programming.
If the controller on the vehicle has already been updated or programmed, a NO UPDATES AVAILABLE message will be displayed. Check the
part number of the controller on the vehicle and compare it to the part number displayed. If the controller has already been updated, then the DTC
"Vacuum Leak Found (IAC Fully Seated)" actually exists and should be corrected.
8.
The MDS and DRBIII will prompt the operator for any action needed during the remainder of the programming process.
NOTE:
THE FOLLOWING STEPS ARE REQUIRED BY LAW.
