P0730

P0730-INCORRECT GEAR RATIO

For a complete wiring diagram refer to Diagrams/Electrical. Electrical Diagrams


Theory of Operation


The Transmission Control Module (TCM) constantly calculates what the output shaft speed should be in any given gear based on the input speed sensor, output speed sensor and the current gear state.



When Monitored:
- Output rpm is greater than 250 rpm, Transmission is in Drive, no electrical DTCs present, transmission not currently in a gear shift.

Set Condition:
- If the calculated ratio does not match the predetermined ratio for the current gear for more than 2.5 seconds, this DTC will set.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. AS68RC Pre-Diagnostic Troubleshooting Procedure



Diagnostic Test


1. CHECK FOR INTERNAL TRANSMISSION PROBLEM

Determine if there are any Transmission mechanical problems present.

Remove the Transmission Oil Pan and inspect for excessive debris or a plugged Transmission Oil Filter.

Inspect valve body for foreign material.

Is there any Transmission mechanical problems present?

Yes

- Repair as necessary.
- Perform AS68RC VERIFICATION TEST. Verification Tests

No

- Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM.
- Perform AS68RC VERIFICATION TEST. Verification Tests