Improper Ratio

P0730 - IMPROPER RATIO





When Monitored and Set Condition

- When Monitored: Engine speed greater than 450 RPM, output speed greater than 180 RPM, no N2 - N3 input speed sensor errors present, no gear selector lever errors present, no ABS system errors, and all wheel speeds above 450 RPM.
- Set Condition: No shifting operation and detected gear is not the actual gear. No shifting operation - detected (calculated) gear is less than actual (expected) gear, no plausible gear is calculated, actual turbine speed - calculated turbine speed >300 RPM or calculated transmission ratio is above threshold. During an Upshift - detected (calculated) gear is less than actual (expected) gear-1. During Downshift - detected (calculated) gear is less than actual (expected) gear.





For a complete Transmission Control Module Circuit Diagram, [1][2]Automatic Transmission/Transaxle.

Diagnostic Test

1. PRE-DIAGNOSTIC CHECK OUT
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.

NOTE: Always perform diagnostics with a fully charged battery to avoid false symptoms.

With the scan tool, read Engine DTCs. Check and repair all engine DTCs prior to performing transmission symptom diagnostics.
With the scan tool, read and record all Transmission DTCs.

NOTE: Check connectors - Clean/repair as necessary. Poor pin to terminal connections can set DTCs.

Using the wiring diagram/schematic as a guide, inspect the wiring and connectors. Repair as necessary.
Most DTCs set on start up but some must be set by driving the vehicle such that all diagnostic monitors have run.

NOTE: Check for any Technical Service Bulletins that may apply.

Perform this procedure prior to Symptom diagnosis.

Continue

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2. TRANSMISSION MECHANICAL PROBLEM
Determine if there are any Transmission Mechanical problems present.
Remove the Transmission Oil Pan and inspect for debris or a plugged Transmission Oil Filter.

Is there any debris, plugged Transmission Oil Filter, or signs of an internal transmission problem?

Yes

- Refer to Transmission for the proper repair procedure. Pay particular attention to the valve body components and stuck solenoids.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test

No

- Replace the Transmission Control Module. Transmission Control Module - Removal.
- Perform NAG1 TRANSMISSION VERIFICATION TEST. Transmission Verification Test