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P0731-GEAR RATIO ERROR IN 1ST (CONTINUED) Diagnostic Test 1. DETERMINING IF RELATED DTC’S ARE PRESENT With the scan tool, check for other transmission DTC’s If any of these DTC’s are present, perform their respective tests first. Are there any Transmission; solenoid, line pressure, speed sensor, and/or loss of prime DTC’s present? Yes >> Refer to the Transmission category and perform the appropriate symptom. If any of these DTCs are present, they may cause a Speed Ratio Error. Perform the test for P0944 first if it is present. Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. No >> Go To 2 2. CHECK TO SEE IF DTC P0731 IS CURRENT With the scan tool, perform the 1st Gear Clutch Test. Follow the instructions on the scan tool. 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 3 No >> Go To 4 3. CHECK FOR INTERMITTENT OPERATION The conditions to set this DTC are not currently present. With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set. - If the DTC Event Data shows fault P0731 was set in Park, Reverse, or Neutral, replace the Powertrain Control - If the DTC Event Data shows fault P0731 set with input RPM = zero, check the input speed sensor and related - If the DTC Event Data shows fault P0731 set with line pressure significantly below desired line pressure, check for - If the DTC Event Data shows fault P0731 set with the UD pressure switch open (but line pressure matches Check the gearshift linkage adjustment. Intermittent Gear Ratio DTCs can be set by problems in the Input and Output Speed Sensor circuits and/or Speed Remove the Starter Relay. NOTE: Failure to remove the Starter Relay can cause a Transmission - No Response condition. Wiggle wiring and connectors while checking for intermittent operation with the Transmission Simulator. Gear ratio DTC’s can also be set under extreme temperature conditions. Verify if the problem is only experienced under extreme hot or cold conditions. Were there any problems found. Yes >> Repair as necessary. Perform 45RFE/545RFE TRANSMISSION VERIFICATION TEST - VER 1. No >> Test Complete. HB AUTOMATIC TRANSMISSION 545RFE - ELECTRICAL DIAGNOSTICS 21 - 401 |