4-Speed Models

Turn ignition off. Install scan tool. Turn ignition on. Using scan tool, monitor A/T control relay output voltage. Is battery voltage present? If so, go to next step. If not, see DTC 54 (P1751): A/T CONTROL RELAY CIRCUIT OPEN/SHORTED TO GROUND under DIAGNOSTIC TESTS.
Place gearshift lever in "P" position. Turn ignition on, engine off. Using scan tool, monitor PNP switch while moving gearshift lever to each position. Does gearshift lever position match scan tool display? If so, go to next step. If not, see DTC 27 (P0705): PARK/NEUTRAL POSITION SWITCH CIRCUIT - OPEN and DTC 28 (P0705): PARK/NEUTRAL POSITION SWITCH CIRCUIT - SHORT under DIAGNOSTIC TESTS.
Using scan tool, monitor throttle position while slowly depressing and releasing accelerator pedal. Is the voltage displayed 535-735 millivolts with accelerator fully closed and gradually increases to 4500-5500 millivolts with accelerator fully open? If so, go to next step. If not, inspect using the following DTC tests under DIAGNOSTIC TESTS:
Using scan tool, monitor stoplight switch while depressing and releasing brake pedal. Does scan tool display ON when brake pedal is depressed and OFF when released. If so, go to next step. If not, see DTC 26: STOPLIGHT SWITCH CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
With gearshift lever in "P" position, attempt to start engine. If engine starts, repeat procedure with gearshift lever in "N" position. Does engine start in both gearshift lever positions? If so, go to next step. If not, see appropriate STARTERS article in STARTING & CHARGING SYSTEMS.
Using scan tool, monitor transmission fluid temperature. Drive vehicle for 15 minutes. Does scan tool indicate transmission fluid temperature gradually increases to 158-176°F (70-80°C)? If so, go to next step. If not, see DTC 15 (P0713): TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT - OPEN and DTC 16 (P0712): TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT - SHORTED under DIAGNOSTIC TESTS.
With engine idling and gearshift lever in "N" position, repeat procedure in step 4 . If okay, go to next step.
Using scan tool, monitor dual pressure switch while turning A/C on and off. Does scan tool indicate ON and OFF? If so, go to next step. If not, see TEST O: VEHICLE SHIFTS DIFFERENTLY WITH A/C ENGAGED under SYMPTOM TESTS.
Using scan tool, monitor engine speed with accelerator depressed and released. Does engine tachometer and scan tool display the same RPM? If so, go to next step. If not, see DTC 21: CRANKSHAFT POSITION SENSOR CIRCUIT - OPEN under DIAGNOSTIC TESTS.
With engine idling and gearshift lever in "N" position, move gearshift lever from "N" to "D" position and then from "N" to "R" position. There should be no abnormal shift shock or time delay when engaging (shift engagement should occur within 2 seconds). Are shift engagements as specified? If so, go to next step. If not, see appropriate symptom in SYMPTOM TESTS.
Road test vehicle on a flat straight road under the following conditions:
- With engine idling, gearshift lever in "L" position and vehicle stopped. Scan tool should indicate that MPH is zero. If not, see DTC 29: VEHICLE SPEED SENSOR CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
- Drive vehicle at a constant speed of 6 MPH with gearshift lever in "L" position. Scan tool should indicate the following:
  1. Transmission in 1st gear.
  2. Low-reverse solenoid valve duty percentage is zero percent. If not, see DTC 31 (P0753): LOW-REVERSE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  3. Underdrive solenoid valve duty percentage is zero percent. If not, see DTC 32 (P0758): UNDERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  4. Second solenoid valve duty percentage is 100 percent. If not, see DTC 33 (P0763): SECOND SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  5. Overdrive solenoid valve duty percentage is 100 percent. If not, see DTC 34 (P0768): OVERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
- Drive vehicle at a constant speed of 19 MPH with gearshift lever in "2" position. Scan tool should indicate the following:
  1. Transmission is in 2nd gear.
  2. Low-reverse solenoid valve duty percentage is 100 percent. If not, see DTC 31 (P0753): LOW-REVERSE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  3. Underdrive solenoid valve duty percentage is zero percent. If not, see DTC 32 (P0758): UNDERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  4. Second solenoid valve duty percentage is zero percent. If not, see DTC 33 (P0763): SECOND SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  5. Overdrive solenoid valve duty percentage is 100 percent. If not, see DTC 34 (P0768): OVERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
- Drive vehicle at a constant speed of 31 MPH with gearshift lever in "3" position. Scan tool should indicate the following:
  1. Transmission is in 3rd gear.
  2. Low-reverse solenoid valve duty percentage is 100 percent. If not, see DTC 31 (P0753): LOW-REVERSE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  3. Underdrive solenoid valve duty percentage is zero percent. If not, see DTC 32 (P0758): UNDERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  4. Second solenoid valve duty percentage is 100 percent. If not, see DTC 33 (P0763): SECOND SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  5. Overdrive solenoid valve duty percentage is zero percent. If not, see DTC 34 (P0768): OVERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  6. Vehicle speed is 31 MPH. If not, see DTC 29: VEHICLE SPEED SENSOR CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  7. Input shaft speed is 1400-1700 RPM. If not, see DTC 22 (P0715): INPUT SHAFT SPEED SENSOR CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  8. Output shaft speed is 1400-1700 RPM. If not, see DTC 23 (P0720): OUTPUT SHAFT SPEED SENSOR CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
- With gearshift lever in "D" position, drive vehicle at a constant speed of 31 MPH. Scan tool should indicate the following:
  1. Transmission is in 4th gear.
  2. Low-reverse solenoid valve duty percentage is 100 percent. If not, see DTC 31 (P0753): LOW-REVERSE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  3. Underdrive solenoid valve duty percentage is 100 percent. If not, see DTC 32 (P0758): UNDERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  4. Second solenoid valve duty percentage is zero percent. If not, see DTC 33 (P0763): SECOND SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
  5. Overdrive solenoid valve duty percentage is zero percent. If not, see DTC 34 (P0768): OVERDRIVE SOLENOID VALVE CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
With gearshift lever in "3" position, road test vehicle on a flat straight road under the following:
- Drive vehicle at 31 MPH in 3rd gear. Scan tool should indicate the following:
  1. TCC solenoid valve duty percentage is 70-90 percent.
  2. TCC slippage is -10 to 10 RPM.
- Drive vehicle at 31 MPH in 3rd gear. Release accelerator pedal. Scan tool should indicate the following:
  1. TCC solenoid valve duty percentage is 70-90 percent and then zero percent when accelerator pedal is released.
  2. TCC slippage is -300 to -100 RPM and then to 300 RPM when accelerator pedal is released.
    If TCC solenoid valve duty percentage and/or TCC slippage is not as specified, inspect using the following DTC tests under DIAGNOSTIC TESTS:
Using scan tool, turn off the INVECS-II function. Using scan tool, monitor TP sensor voltage and output shaft speed. Road test vehicle on a flat straight road with gearshift lever in "D" position as follows:
- Accelerate to 4th gear using TP sensor output of 1.5 volts (accelerator opening angle of 30 percent).
- Slowly decelerate to a stop.
- Accelerate to 4th gear using TP sensor output of 2.5 volts (accelerator opening angle of 50 percent).
Ensure the shift points correspond with the scan tool display and the TP sensor voltage and output shaft speed, which are shown in the standard shift pattern. See SHIFT SPEED SPECIFICATIONS . If any of the following occurs, see corresponding repair reference:
- Malfunction when shifting - See TEST I: SHIFT SHOCK & SLIPPING under SYMPTOM TESTS.
- Does not shift according to instructions - See TEST J: INCORRECT SHIFT POINTS (ALL GEARS) or TEST K: INCORRECT SHIFT POINTS (SOME GEARS) under SYMPTOM TESTS.
- Does not shift - See DTC 22 (P0715): INPUT SHAFT SPEED SENSOR CIRCUIT - OPEN/SHORTED and DTC 23 (P0720): OUTPUT SHAFT SPEED SENSOR CIRCUIT - OPEN/SHORTED under DIAGNOSTIC TESTS.
Using scan tool, monitor indicated transmission gear. Road test as follows:
- While driving vehicle at 37 MPH and gearshift lever in "D" position, move gearshift lever to "3" position. Transmission should perform 4-3 shift. If not, inspect using the following DTC tests under DIAGNOSTIC TESTS:
- While driving vehicle at 25 MPH and gearshift lever in "3" position, move gearshift lever to "2" position. Transmission should perform 3-2 shift. If not, inspect using the following DTC tests under DIAGNOSTIC TESTS:
- While driving vehicle at 12 MPH and gearshift lever in "2" position, move gearshift lever to "L" position. Transmission should perform 2-1 shift. If not, inspect using the following DTC tests under DIAGNOSTIC TESTS:
Using scan tool, monitor input and output shaft speed. Move gearshift lever to "R" position. Drive vehicle at constant speed of 6 MPH. The ratio between input and output shaft speed should be the same as the gear ratio (2.720:1). If not, inspect using the following DTC tests under DIAGNOSTIC TESTS: