P0730

Diagnostic Chart:

Circuit Description
The Vehicle Control Module (VCM) calculates the gear ratio based on the Automatic Transmission Input Shaft Speed (A/T ISS) and Output Shaft Speed (OSS) Sensor readings. The VCM compares the known transmission ratio calibration values to the calculated ratio.

If the VCM detects an unknown ratio, then Diagnostic Trouble Code (DTC) P0730 sets. DTC P0730 is a type D DTC.

Conditions for Setting the DTC
The following conditions are met for 10 seconds.

^ No TP DTCs P0121, P0122, or P123.
^ No OSS DTC P0502.
^ No A/T ISS DTCs P0716 or P0717.
^ No TFP Val. Position Sw. DTC P1810.
^ No Four Wheel Drive Lo DTC 1875.
^ The Four Wheel Drive Lo fail counters are clear.
^ The Vehicle Speed is greater than 11 km/h (7 mph).
^ The TP Angle is greater than 25%.
^ The Transmission Fluid Temperature (TFT) is greater than 20°C (88°F).
^ 10 seconds must have elapsed since the last gear range change.
^ The engine torque is 100 Nm (80 lb. ft) to the following:

- 470 Nm (375 lb. ft).

^ The engine is running for greater than 5 seconds and is not in fuel cut off.
^ The engine vacuum is 0-105 kPa.
^ The Gear Ratio is one of the following:

- Greater than 2.63 or less than 2.38.
- Greater than 1.58 or less than 1.43.
- Greater than 1.05 or less than 0.95.
- Greater than 0.80 or less than 0.70.
- Greater than 2.17 or less than 1.97.

Action Taken When the DTC Sets
^ The VCM commands maximum line pressure.
^ The VCM freezes shift adapts.

Conditions for Clearing the DTC

1. A scan tool can clear the DTC from the VCM history. The VCM clears the DTC from the VCM history if the vehicle completes 40 warm-up cycles without a failure reported.
2. The VCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the VCM.

Diagnostic Aids

^ Inspect the wiring for poor electrical connections at the VCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following problems:

- A bent terminal.
- A backed out terminal.
- A damaged terminal.
- Poor terminal tension.
- A chafed wire.
- A broken wire inside the insulation.

^ When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change.
^ First diagnose and clear any engine DTCs or TP Sensor codes that are present. Then inspect for any transmission DTCs that may have reset.

^ A false or incorrect A/T OSS or A/T ISS signal can set DTC P0730.
^ Sticking or contaminated shift valves may cause intermittent incorrect gear ratios.
^ Inspect for any improperly installed after-market equipment.
^ Refer to the Shift Solenoid Valve State and Gear Ratio table. Shift Solenoid Valve State and Gear Ratio

Test Description
The numbers below refer to the step numbers on the diagnostic table.

3. This Step tests the indicated range signal to the actual selected range. A faulty TFP Val. Position Sw. could set DTC P1810.
4. This step tests for proper ratios in each commanded gear state.