Engine, A/T Controls - MIL ON/Underhood Tapping Noises
NUMBER: 18-012-11 REV. AGROUP: Vehicle Performance
DATE: March 29, 2011
THIS BULLETIN SUPERSEDES SERVICE BULLETIN 18-012-11, DATED FEBRUARY 24, 2011, WHICH SHOULD BE REMOVED FROM YOUR FILES. THIS ISA COMPLETE REVISION AND NO ASTERISKS HAVE BEEN USED TO HIGHLIGHT REVISIONS.
HELP USING THE wiTECH DIAGNOSTIC APPLICATION FOR FLASHING AN ECU IS AVAILABLE BY SELECTING "HELP" THEN "HELP CONTENTS" AT THE TOP OF THE wiTECH DIAGNOSTIC APPLICATION WINDOW.
THE wiTECH SOFTWARE LEVEL MUST BE AT RELEASE 11.03 OR HIGHER TO PERFORM THIS PROCEDURE.
SUBJECT:
Flash: MIL Illumination Or lapping Sound Heard Under Hood At Key Up Or After Key Off With Driveability And Transmission Improvements
OVERVIEW:
This bulletin involves flash reprogramming the Powertrain Control Module (PCM) and then the Transmission Control Module (TCM) with new software and then performing a TCM module initialization.
NOTE:
A "Initialize EGS" (TCM module initialization) must be performed after the reprograming of the PCM and TCM for WK Bodies built before December 20, 2010 to take full advantage of the new software features. If Service Bulletin 18-012-11 has already been performed then a TCM module initialization is not necessary.
MODELS:
2011 (WD) Durango
2011 (WK) Grand Cherokee
NOTE:
This Service Bulletin applies to vehicles equipped with a 3.6L engine (Sales Code ERB) and NAG1 transmission (Sales Code DGJ) built before March 6, 2011 (MDH 0306XX).
SYMPTOM/CONDITION:
Some customers may notice any of the following;
MIL Illumination
Upon further investigation the Technician may find that any of the following Diagnostic Trouble Codes (DTC) have been set:
a. P0344 - Camshaft Position Sensor Intermittent - Bank 1 Sensor 1 (WK Body only)
b. P0349 - Camshaft Position Sensor Circuit Intermittent - Bank 2 Sensor 1 (WK Body only)
c. P0369 - Camshaft Position Sensor Intermittent - Bank 1 Sensor 2 (WK Body only)
d. P0394 - Bank 2 Camshaft Position Sensor 2/2 Circuit Intermittent (WK Body only)
e. PO5OB - Cold Start Ignition Timing Performance (WK Body only)
f. P0730 - Incorrect Gear Ratio (WK Body only)
g. P0219 - Engine Overspeed (WK Body only)
h. P0108 - Manifold Absolute Pressure Sensor Circuit High (WK/WD Bodies)
i. P0522 - Engine Oil Pressure Sensor Circuit Low (WK/WD Bodies)
j. PO6DD - Engine Oil Pressure Control Circuit Stuck Off (WK/WD Bodies)
k. P0298 - Engine Oil Temperature Too High (WK/WD Bodies)
Driveability Improvements or Tapping Sound WK Body only
a. A slight tapping sound is heard from under the hood. This could also be described as a rattle or clicking sound also. This condition can be heard when the ignition key is turned to accessory or start or right after ignition key has been turned off. This condition was caused by a cleaning routine of the cam actuator controller by the PCM. To correct this condition a calibration change was made to modify the duty cycle and frequency of the PCM controlled cleaning routine of the cam actuator.
b. At a light throttle tip in (2 to 6%) the RPM may oscillate slightly (+1-200 rpm). If the throttle tip in is increased then the issue is not present.
c. Lacks Performance. Some driving conditions can produce circumstances where some customers may perceive more pedal effort is required to get the Powertrain to accelerate the vehicle as desired. The PCM calibration for pedal vs. torque relationship was changed to allow for more torque delivery at less pedal effort/travel. In accordance with this PCM calibration change, the TCM was re-calibrated to provide optimal performance and fuel economy. The combined PCM and TCM software improvements will translate into a feeling of improved performance to the driver.
d. Customer describes a temporary "Loss of Power" event due to transmission going to Neutral during a heavy throttle 4-3 downshift. This may happen when driving at moderate speed, 35 to 70 MPH (56 to 112 KPH) when the driver accelerates with pedal input from 40-100% triggering a 4-3 downshift. The may set the P0730 - Incorrect Gear Ratio DIG along with the MIL light ON and cause a Neutral condition within the transmission. This will typically be described as a "Loss of Power" complaint. The MIL for the P0730 will clear after 3 consecutive ignition cycles without setting another P0730 DTC. The P0730 DTC will remain stored in the TCM for 40 consecutive "good" ignition cycles and then be cleared. To correct this condition the TCM pressure control and torque management were re-calibrated improve the 4-3 downshift control during these conditions.
Transmission Improvements WK Body only:
a. Lack of performance feeling during low vehicle speed turning or cornering maneuvers. To correct this condition a new TCM feature was developed to detect when the vehicle is in a turn and will then not perform an upshift.
b. Harsh 3-4-3 change mind shift. This happens when driving at moderate speed of 30 to 50 mph (48 to 80 kmh) when the driver reduces accelerator pedal input to 5-10%. The TCM then schedules a 3-4 upshift. When the driver accelerates rapidly, pedal input from 40-100% this will CANCEL the 3-4 upshift and trigger a "change mind" shift and revert back to 3rd gear. The TCM "change mind" pressure control and torque management were re-calibrated to smooth the shift control during this maneuver.
c. Noticeable higher engine RPM during low speed driving. This condition will be noticed during parking lot or city traffic low speed driving. The TCM logic was refined to keep the upshift inhibit more linear vs. vehicle speed.
d. Engagement shudder when transmission is shifted into DRIVE or REVERSE immediately after the vehicle is starting. This shudder is caused by a lack of hydraulic prime in the transmission pump which requires a higher pressure demand to the applying clutch to avoid the shudder during the engagement. The TCM logic was changed to detect an engagement to DRIVE or REVERSE immediately after the engine starting which will then utilizing a special pressure apply rate ONLY during these conditions.
e. More pedal effort to maintain speed while towing trailer during HOT ambient conditions of greater than 100° F (37° C). The TCM logic was optimized to improve this feeling.
f. Overall Improved shift quality. TCM calibrations were changed to deliver optimal shift quality during all driving conditions.
g. Poor shift quality when using autostick (-) lever to initiate a transmission down shift. This will be notice when tapping lever (-) minus around 35 to 45 MPH (56 to 72 KPH) with a light accelerator pedal input of 5 to 10%. This was caused by B2 clutch apply pressure being calibrated too high for the 4-3 downshift. The TCM calibration was changed to lower the B2 clutch apply pressure during this maneuver.
DIAGNOSIS:
Using a Scan Tool (wiTECH(TM)) with the appropriate Diagnostic Procedures available in TechCONNECT, verify no DTC's are set. If DTC's are present other then the one listed above record them on the repair order and repair as necessary before proceeding further with this bulletin.
If the above condition is present, perform the Repair Procedure.
PARTS REQUIRED:
REPAIR PROCEDURE:
NOTE:
Install a battery charger to ensure battery voltage does not drop below 13.2 volts. Do not allow the charging voltage to climb above 13.5 volts during the flash process.
NOTE:
If this flash process is interrupted/aborted, the flash should be restarted.
1. Reprogram the PCM with the latest software. Help using the wiTECH diagnostic application for flashing an ECU is available by selecting "Help" then "Help Contents" at the top of the wiTECH diagnostic application window.
2. Is the vehicle a WD body?
a. Yes >>> proceed to Step # 8
b. No >>> proceed to Step # 3
3. Has Service Bulletin 18-012-11 been performed?
a. Yes >>> proceed to Step # 8
b. No >>> proceed to Step # 4
4. Connect wiTECH to the vehicle.
5. Select the "Home Screen".
6. Is the TCM up to date?
a. Yes >>> proceed to Step # 8
b. No >>> proceed to Step # 7
7. Reprogram the TCM with the latest software. Help using the wiTECH diagnostic application for flashing an ECU is available by selecting "Help then "Help Contents at the top of the wiTECH diagnostic application window. After TCM reprogramming, the following must be performed:
a. From the "Misc Function" tab at the TCM home page Performing a "Initialize EGS" (TCM module initialization)..
NOTE:
A "Initialize EGS" (TCM module initialization) must be performed after the reprograming of the PCM and TCM for WK Bodies built before December 20, 2010 to take full advantage of the new software features. If Service Bulletin 18-012-11 has already been performed then a TCM module initialization is not necessary.
8. Reprogram the PCM with the latest software. Help using the wiTECH diagnostic application for flashing an ECU is available by selecting "Help" then "Help Contents" at the top of the wiTECH diagnostic application window. After PCM reprogramming, the following must be performed:
a. Clear any DTC's that may have been set in other modules due to reprogramming. The wiTECH application will automatically present all DTCs after the flash and allow the tech to clear them.
9. Type the necessary information on the "Authorized Modification Label" and attach it near the VECI label.
NOTE:
Clear any DTC's that may have been set in other modules due to reprogramming. The wiTECH application will automatically present all DTCs after the flash and allow the tech to clear them.
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE:
FAILURE CODE:
Disclaimer:
This bulletin is supplied as technical information only and is not an authorization for repair.