t m1606 -670C, 670CH, 672CH 770C, 770CH, 772CH Mot or GradersOperat ionand TestTransmission Diagnost ic Trouble Codes F301 - F308Transmission Diagnostic Trouble Codes F301-F308Troubleshooting Tips F301-F308 Transmission Gear Solenoid CodesF301 through F308 diagnostic trouble code. These codes initially occur only when in gear. The diagnostic trouble code maydisplay as shifting into gear but the transmission does not go into neutral until the problem solenoid circuit is used. After this,only one gear will operate after each return to neutral. The grader can still be operated in what is called SOLENOID LIMPHOME MODE. This can be confusing when troubleshooting as different gears work depending on which solenoid failed. TheSOLENOID LIMP HOME MODE is started by shifting to neutral position with the shifter and back into the gear you desire tooperate. You must shift quickly to the desired gear. The transmission will operate in only this gear and movement of the shifterwill not change from this first gear selection in which motion begins. To change to another gear, operator must shift to neutraland back into desired gear.If no diagnostic trouble codes appear and your gear position does not match vehicle motion you may be in Shifter Limp Home.You get much the same machine operation in both these modes. Refer to Shifter Limp Home.The diagnostic trouble code that indicates these solenoid faults stays active and can be checked by pressing the select buttonsix times to see if the fault code is still active. If the code is gone the service condition is cleared and the transmission willreturn to using all gears correctly by canceling the solenoid limp home mode by going into neutral and back into any gear twotimes. It is recommended that the grader is shut off and restarted, then shift into all gears to verify the solenoids are workingcorrectly.The diagnostic trouble code does not display again by shifting in and out of gear. You must push the select button 6 times tosee if code is still active.INTERMITTENT problem. If problem is intermittent you will need to be sure to turn off the grader and restart it to verify theservice error is not present. The diagnostic trouble code will not redisplay on the monitor when the problem clears. If all gearswork correctly the problem is no longer present. If still have loss of some gear positions restart the machine to check forcurrent diagnostic trouble code.Transmission Solenoid Circuit DiagramT120378-19: Transmission Solenoid Circuit Diagram (S.N. -575171)T128604-19: Transmission Solenoid Circuit Diagram (S.N. 575172-)The above diagram can be used to trace the individual wires for the transmission solenoid circuits through the machine. Forexample, to trace the circuit for transmission solenoid 1, first determine which wires energize the solenoid. Transmissionsolenoid 1 contains R22 BLK and T05 BLU. Second find the wires on the left hand side of the diagram where they leave thePgina1 de415/07/2015 file:///C:/ProgramData/Service%20ADVISOR/Temp/tm1606_TXTX17864920470535.htmltransmission controller unit (A1). The boxes represent connectors or components, the wires between the boxes represent theactual harnesses. The numbers inside the boxes signify the pin number within the connector. For the example, R22 BLK takesthe following path. Exits the transmission controller on pin B1 within connector J3. Passes through the side console harness. Passes through the side console harness to platform harness connector (X3) on pin 56. Passes through the platform harness. Passes through the platform harness to transmission harness connector (X13) on pin 10. Passes through the transmission harness to transmission solenoid 1 (not shown).The machine operation column in the chart indicates which gears are possible with each solenoid failure mode.-: Transmission Diagnostic Trouble Codes F301-F308SERVICECODETECH MANUALDESCRIPTION POSSIBLE CAUSEMACHINEOPERATION SOLUTIONF301Displayed tooperator oneachoccurenceTransmissionSolenoid 1Low or zerocurrentSolenoid Unplugged. Neutral: SolenoidLimp Home Gearsare (F-2,4,6) (R-1,2,3,4,5,6)Reset in NeutralCheck connection at solenoid.Broken, open wire, open inY4 solenoid coil, or badconnection. Check WiresT05 BLU and R22 BLK atTCU.Pin J3-A3 and J3-B1.Disconnect connector J3 from TCU.Measure the resistance of the circuitfrom connector J3 (across pins B1 andA3). Resistance should measure 40 5. Make sure wire is making contact tocontroller connector pin.Return wire of Solenoidshorted or connected toground. Check wire R22BLK. (This wire CANNOTbe connected to theframe.)Unplug solenoid connector and TCUbox. Check for continuity to GND ateither TCU or solenoid. Wire should beOPEN (High Ohms to GND).F302Displayed tooperator oneachoccurenceTransmissionSolenoid 2Low or zerocurrentSolenoid Unplugged. Neutral:Solenoid LimpHome Gearsare (F-1,2,3) (R-1,6)Reset in NeutralCheck connection at solenoid.Broken, open wire, open inY5 solenoid coil, or badconnection. Check Wires T04BLU and R01 BLK at TCU.Pin J3-B2 and J3-B3.Disconnect connector J3 from TCU.Measure the resistance of the circuit fromconnector J3 (across pins B3 and B2).Resistance should measure 40 5 .Make sure wire is making contact tocontroller connector pin.Return wire of Solenoidshorted or connected toground. Check wire R01BLK. (This wire CANNOT beconnected to the frame.)Unplug solenoid connector and TCU box.Check for continuity to GND at either TCUor solenoid. Wire should be OPEN (HighOhms to GND).F303Displayed tooperator oneachoccurenceTransmissionSolenoid 3Low or zerocurrentSolenoid Unplugged. Neutral: SolenoidLimp Home Gearsare (F-1,2,3,4,5,6)(R-2,4,6)Reset in NeutralCheck connection at solenoid.Broken, open wire, open in Disconnect connector J3 from TCU.Pgina2 de415/07/2015 file:///C:/ProgramData/Service%20ADVISOR/Temp/tm1606_TXTX17864920470535.htmlY6 solenoid coil, or badconnection. Check WiresT07 BLU and R04 BLK atTCU.Pin J3-C1 and J3-C2.Measure the resistance of the circuit fromconnector J3 (across pins C1 and C2).Resistance should measure 40 5 .Make sure wire is making contact tocontroller connector pin.Return wire of Solenoidshorted or connected toground. Check wire R04BLK. (This wire CANNOT beconnected to the frame.)Unplug solenoid connector and TCU box.Check for continuity to GND at eitherTCU or solenoid. Wire should be OPEN(High Ohms to GND).F304Displayed tooperator oneachoccurenceTransmissionSolenoid 4Low or zerocurrentSolenoid Unplugged. Neutral: SolenoidLimp Home Gearsare (F-1,2,3,4,5,6)(R-1,3,5)Reset in NeutralCheck connection at solenoid.Broken, open wire, open inY7 solenoid coil, or badconnection. Check WiresT06 BLU and R03 BLK atTCU.Disconnect connector J3 from TCU.Measure the resistance of the circuit fromconnector J3 (across pins D1 and C3).Resistance should measure 40 5 .Make sure wire is making contact tocontroller connector pin.Pin J3-C3 and J3-D1.Return wire of Solenoidshorted or connected toground. Check wire R03BLK. (This wire CANNOT beconnected to the frame.)Unplug solenoid connector and TCU box.Check for continuity to GND at eitherTCU or solenoid. Wire should be OPEN(High Ohms to GND).F305Displayed tooperator oneachoccurenceTransmissionSolenoid ASolenoid Unplugged. Neutral:Solenoid LimpHome Gears are(F-3,4,5,6) (R-3,4,5,6)Reset in NeutralCheck connection at solenoid.Low or zerocurrentBroken, open wire, open inY8 solenoid coil, or badconnection. Check WiresT08 BLU and R05 BLK atTCU.Pin J3-D2 and J3-D3.Disconnect connector J3 from TCU.Measure the resistance of the circuit fromconnector J3 (across pins D2 and D3).Resistance should measure 40 5 .Make sure wire is making contact tocontroller connector pin.Return wire of Solenoidshorted or connected toground. Check wire R05BLK. (This wire CANNOT beconnected to the frame.)Unplug solenoid connector and TCU box.Check for continuity to GND at either TCUor solenoid. Wire should be OPEN (HighOhms to GND).F306Displayed tooperator oneachoccurenceTransmissionSolenoid BLow or zerocurrentSolenoid Unplugged. Neutral:Solenoid LimpHome Gears are(F-1,2,3,4) (R-1,2,3,4)Reset in NeutralCheck connection at solenoid.Broken, open wire, open inY9 solenoid coil, or badconnection. Check WiresT09 BLU and R06 BLK atTCU.Disconnect connector J3 from TCU.Measure the resistance of the circuit fromconnector J3 (across pins E1 and E2).Resistance should measure 40 5 .Make sure wire is making contact tocontroller connector pin.Pin J3-E1 and J3-E2. Unplug solenoid connector and TCU box.Pgina3 de415/07/2015 file:///C:/ProgramData/Service%20ADVISOR/Temp/tm1606_TXTX17864920470535.htmlReturn wire of Solenoidshorted or connected toground. Check wire R06BLK. (This wire CANNOT beconnected to the frame.)Check for continuity to GND at either TCUor solenoid. Wire should be OPEN (HighOhms to GND).F307Displayed tooperator oneachoccurenceTransmissionSolenoid CLow or zerocurrentSolenoid Unplugged. Neutral:Solenoid LimpHome Gears are(F-1,2,5,6) (R-1,2,5,6)Reset in NeutralCheck connection at solenoid.Broken, open wire, open inY10 solenoid coil, or badconnection. Check WiresT10 BLU and R07 BLK atTCU.Pin J3-E3 and J3-F1.Disconnect connector J3 from TCU.Measure the resistance of the circuit fromconnector J3 (across pins E3 and F1).Resistance should measure 40 5 .Make sure wire is making contact tocontroller connector pin.Return wire of Solenoidshorted or connected toground. Check wire R07BLK. (This wire CANNOT beconnected to the frame.)Unplug solenoid connector and TCU box.Check for continuity to GND at either TCUor solenoid. Wire should be OPEN (HighOhms to GND).F308Displayed tooperator oneachoccurenceTransmissionSolenoid DLow or zerocurrentSolenoid Unplugged. Neutral: SolenoidLimp Home Gearsare (F-1,2,3,4,5,6)(R-1,2,3,4,5,6)Reset in NeutralCheck connection at solenoid.Broken, open wire, open inY11 solenoid coil, or badconnection. Check WiresT11 BLU and R08 BLK atTCU.Pin J3-F2 and J3-F3.Disconnect connector J3 from TCU.Measure the resistance of the circuitfrom connector J3 (across pins F2 andF3). Resistance should measure 40 5. Make sure wire is making contact tocontroller connector pin.Return wire of Solenoidshorted or connected toground. Check wire R08BLK. (This wire CANNOTbe connected to the frame.)Unplug solenoid connector and TCU box.Check for continuity to GND at eitherTCU or solenoid. Wire should be OPEN(High Ohms to GND).CED,TX17864,1048-19-19990303Pgina4 de415/07/2015 file:///C:/ProgramData/Service%20ADVISOR/Temp/tm1606_TXTX17864920470535.html