Engine Controls - Hesitation/Low Power on Tip-In
NUMBER: 18-035-03GROUP: Vehicle Performance
DATE: October 3, 2003
THIS BULLETIN IS BEING PROVIDED IN ADVANCE. THE SOFTWARE WILL BE AVAILABLE ON TechCONNECT ON OR AFTER OCTOBER 28, 2003.
SUBJECT:
Hesitation On Throttle Tip-In After Prolonged Closed Throttle
OVERVIEW:
This bulletin involves erasing and reprogramming the Powertrain Control Module (PCM) with new software.
MODELS:
2003 (ZB) Viper
SYMPTOM/CONDITION:
The customer may describe a hesitation or reduced power after completing an upshift during moderate acceleration and/or after a prolonged closed throttle event. The engine must be hot, coolant temperature greater than 90°C (194°F) and ambient temperature greater than 27°C (80°F). The hesitation is most noticeable after completing a first to second upshift.
A condition exists where the spark retards to 0° during prolonged closed throttle. Spark will remain retarded at 0° during the initial throttle tip-in from closed throttle, causing the hesitation. Spark then returns to its normal operating value. The simultaneous conditions required to trigger the hesitation are: Coolant temperature greater than 90°C (194°F), air charge temperature greater than 45°C (113°F) and closed throttle deceleration fuel shut off. This condition will not set Diagnostic Trouble Codes (DTC's).
DIAGNOSIS:
Using a Scan Tool (DRBIII(R)) with the appropriate Diagnostic Procedures Manual, verify all engine systems are functioning as designed. If DTC's are present record them on the repair order and repair as necessary before proceeding further with this bulletin.
If the customer describes, or the technician experiences the Symptom/Condition, perform the Repair Procedure.
PARTS REQUIRED
SPECIAL TOOLS/EQUIPMENT REQUIRED
NOTE:
An updated J1962 cable has been released. This cable has a red colored connector at the DRBIII(R) connection. Use this cable whenever a flash is being performed.
REPAIR PROCEDURE:
NOTE:
Whenever a controller is programmed, the software in the DRBIII(R), must be programmed with the latest revision level available.
NOTE:
If this flash process is interrupted/aborted, the flash should be restarted and then follow the directions on the DRBIII(R).
1. With the ignition switch in the "RUN" position, determine the original part number of the PCM currently in the vehicle. Using the DRBIII(R) select:
a. "DRBIII(R) Standalone"
b. "1998 - 2004 Diagnostics"
c. "All (Except Below)"
d. "Engine"
e. "Module Display"
f. Record the first ten (10) characters of the "PCM part #" on the repair order for later reference.
NOTE:
If the PCM is not operational, the part number can be obtained from the label on the old controller. If the label on the controller is not legible, proceed to next step.
2. Page back to the "Main Menu"
3. Open the hood, install a battery charger and verify battery state is above 11.5 volts.
4. If the old "PCM part #" is known, proceed to step 10. If the old "PCM part #" is not known, proceed to next step.
5. On DealerCONNECT select the "Service" tab.
6. Select "Vehicle Information Plus".
7. Manually enter the VIN and mileage and select "Enter".
8. Select the "Vehicle Option" tab.
9. Under the "Vehicle Option" window, identify and record:
a. Engine.
b. Emissions (Federal or California)
c. Transmission (Automatic, 5-speed manual, etc.).
10. Connect the DRBIII(R) to TechCONNECT and the vehicle. Open TechTOOLS and verify that the "DRBIII(R) Status: Connected" message is in the upper right corner of the TechTOOLS screen.
11. TechTOOLS should automatically populate the VIN in the "Vehicle Criteria" area and the available updates. If not, manually enter the VIN then TechTOOLS will populate the available updates.
12. Determine the proper calibration:
a. If the old "PCM part #" is known, enter the part number of the old controller in the "Parts Criteria" pin window. Proceed to step 13.
b. If the old "PCM part #" is not known, select the correct calibration based on the information that was recorded from "Vehicle Options" in step 9. Proceed to step 14.
13. Select the correct calibration.
14. Select the "Download/Update" button.
15. Monitor the "Flash Download/Update Progress" window on the TechCONNECT and follow the instructions on TechCONNECT/DRBIII(R). When the flash process is completed, proceed to next step.
16. Enter the VIN in the PCM. Using the DRBIII(R) select:
a. "DRBIII(R) Standalone"
b. "1998 - 2004 Diagnostics"
c. "All"
d. "Engine"
e. "Miscellaneous"
f. "Check VIN"
g. Enter the VIN as requested by the DRBIII(R).
17. Update the PCM mileage. Using the DRBIII(R) select:
a. "DRBIII(R) Standalone"
b. "1998 - 2004 Diagnostics"
c. "All (Except Below)"
d. "Engine"
e. "Miscellaneous"
f. "Check PCM Odometer"
g. "NO"
h.Enter the current odometer mileage and then press "Enter".
I. Cycle the ignition key to the OFF position and back to the ON position and then press "Enter".
NOTE:
Due to the PCM programming procedure, a DTC may be set in other modules (TCM, BCM, MIC, SKIM, etc.) within the vehicle, if so equipped. Some DTC's may cause the MIL to illuminate. Check all modules using "Module Scan", record the DTC's, and erase these DTC's prior to returning the vehicle to the customer. Erase any DTC's in the PCM only after all other modules have had their DTC's erased.
NOTE:
The following step is required by law.
18. Type the necessary information on the "Authorized Modification Label" p/n 04275086AB and attach near the VECI label (Fig. 1).
POLICY:
Reimbursable within the provisions of the warranty.
TIME ALLOWANCE
FAILURE CODE