Diagnostic Procedure
WARNING: This page is about a different car, the 2005 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.
P0731-GEAR RATIO ERROR IN 1ST DIAGNOSTIC TEST REFERENCE
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 |
NOTE:
Low fluid level can be the cause of many transmission problems. If the fluid level is low locate and repair the leak then check and adjust the fluid level per the Service Information.
NOTE:
Always perform diagnostics with a fully charged battery to avoid false symptoms. With the DRBIII®, read Engine DTC's. Check and repair all Engine DTC's prior to performing any transmission symptom diagnostics.With the DRBIII®, read Transmission DTC's. Record all DTC's and 1 Trip Failures.
NOTE:
Diagnose 1 Trip Failures as a fully matured DTC. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.Repair as necessary.Perform the Shift Lever Position Test. If the test does not pass, refer to Symptom test for P0706 CHECK SHIFTER SIGNAL .For Gear Ratio DTC's, check and record all CVI's.Most DTC's set on start up but some must be set by driving the vehicle such that all diagnostic monitors have run.
NOTE:
Verify flash level of Powertrain Control Module. Some problems are corrected by software upgrades to the Transmission and Engine software.
NOTE:
Check for applicable TSB's related to the problem. Perform this procedure prior to Symptom diagnosis.ContinueGo To 2 |
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| 2 | With the DRBIII®, read Transmission DTC's. If any of these DTC's are present, perform their respective tests first. Are there any Loss of Prime, Line Pressure Sensor and/or Speed Sensor DTCs present? Yes --> Refer to appropriate test in TRANSMISSION CATEGORY . If any of these DTC's are present, they will cause a gear ratio error. Perform the test for Loss of Prime first if it is present. Perform 42RLE (NGC) TRANSMISSION VERIFICATION TEST - VER 1 . No --> Go To 3 |
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| 3 | With the DRBIII®, perform the 1st gear clutch test. Follow the instructions on the DRBIII®. Increase the throttle angle or TPS Degree to 30° for no more than a few seconds.
CAUTION:
Do not overheat the transmission. Did the Clutch Test pass, Input Speed remain at zero? Yes --> Go To 4 No --> Go To 5 |
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| 4 | The conditions to set this DTC are not current at this time. Check the gearshift linkage adjustment. Gear ratio DTC's can be set by problems in the Input and Output Speed Sensor circuits. If the vehicle passes the Clutch Test and still sets Gear Ratio DTC, check the Speed Sensors for proper operation. Remove the Starter Relay.
CAUTION:
Removal of the Starter Relay is to prevent a Transmission, NO RESPONSE, condition and disable the starter. Check the wiring and connectors for the Speed Sensors for a good connection, then perform a wiggle test using the Transmission Simulator, Miller tool #8333 and the Electronic Transmission Adapter kit 8333-1A. This DTC can also be set under extreme temperature conditions, this is usually caused by an internal problem. Verify if the problem is only experienced under extreme hot or cold conditions. With the DRBIII®, check the EATX EVENT DATA to help identify the conditions in which the DTC was set. Were there any problems found? Yes --> Repair as necessary. Perform 42RLE (NGC) TRANSMISSION VERIFICATION TEST - VER 1 . No --> Test Complete. |
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| 5 | If there are no possible causes remaining, view repair. Repair Repair internal Transmission per the Service Information. Check all of the components related to the UD and LR clutches. Inspect the Oil Pump and repair or replace per the Service Information. Perform 42RLE (NGC) TRANSMISSION VERIFICATION TEST - VER 1 . |
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