Diagnostic Test

WARNING: This page is about a different car, the 2006 Dodge Magnum, 2006 Dodge Charger, and 2006 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

1) CHECK IF PINION FACTOR IS PROGRAMMED
With the scan tool, check if the pinion factor has been programmed in the FCM.

NOTE: If the Pinion Factor is not properly programmed, a Gear Ratio DTC may set.

Was the Pinion Factor properly programmed for the actual tire size and axle ratio of the vehicle?

Yes
1. Go To step 2).
No
1. With the scan tool, properly program the Pinion Factor in the FCM.
2. Perform NAG1 TRANSMISSION VERIFICATION TEST .
2) CHECK FOR OTHER TRANSMISSION DTCS
With the scan tool, check transmission DTCS

Are there any solenoid and/or solenoid supply voltage DTCs present?

Yes
1. Perform appropriate DTC test(s) in this article.
No
1. Go To step 3).
3) CHECK TRANSMISSION FLUID LEVEL
Check the transmission fluid level per the Service Information. (Refer to TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1/FILTER - STANDARD PROCEDURE)

Is the fluid level correct?

Yes
1. Go To step 4).
No
1. Properly adjust the fluid level per the Service Information. (Refer to TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1/FILTER - STANDARD PROCEDURE)
2. Perform NAG1 TRANSMISSION VERIFICATION TEST .
4) CHECK IF DTC IS CURRENT
With the scan tool, record the Environmental Data and erase Transmission DTCs.

NOTE: If the TCM detects and stores a DTC, the TCM also stores the vehicles operating conditions under which the DTC originally set and is located in scan tool under Environmental Data. Before erasing any stored DTCs, record any available data to assist in duplicating the conditions in which the DTC originally set.

Using the Environmental Data recorded earlier, test drive the vehicle while trying to duplicate the conditions in which the DTC originally set.

Did the DTC P0731-GEAR RATIO ERROR IN 1ST reset?

Yes
1. Repair internal transmission as necessary per the Service Information. (Refer to TRANSMISSION/TRANSAXLE/AUTOMATIC - NAG1 - REMOVAL)
2. Perform NAG1 TRANSMISSION VERIFICATION TEST .
No
1. Go To step 5).
5) INTERMITTENT WIRING AND CONNECTORS
The conditions necessary to set this DTC are not present at this time.

Using the schematics as a guide, inspect the wiring and connectors specific to this circuit.

Wiggle the wiring and connectors while checking for any possible open or shorted circuits.

Check for any Service Information Tune-ups or Technical Service Bulletins that may apply.

Were there any problems found?

Yes
1. Repair as necessary.
2. Perform NAG1 TRANSMISSION VERIFICATION TEST .
No
1. Test Complete.