SMU for All 2000 S Series Automatic Transaxle Service Manuals Regarding DTCs P0731, P0732, P0733, P0734, and P0741

The purpose of this bulletin is to update all the 2000 S-Series Automatic Transaxle Service Manuals at your location.

Obtain all the 2000 S-Series Automatic Transaxle Service Manuals at your location and update as indicated below.

Cross out the following pages with a marker or pen:

The powertrain control module (PCM) uses the crankshaft position (CKP) sensor, input speed sensor (ISS) and output speed sensor (OSS) to determine engine speed, input shaft speed and output shaft speed. These sensor readings are used to determine the current gear ratio and RPM slip across the torque converter. The PCM uses this information from the sensors to determine if the commanded gear matches the actual gear. During normal driving conditions, the PCM will adapt main line pressure via the pressure control (PC) solenoid to prevent slipping and harsh shifts. First gear clutch is fed fluid directly from the manual valve and is applied in all forward gears. DTC P0731 sets when 1^st clutch still slips after the PCM has commanded high main line pressure.

DTC P0731 will set if the PCM detects an incorrect actual 1^st gear ratio when 1^st gear is commanded ON when:

OR

Important: If input speed sensor DTCs P0716 or P0717 are present, diagnose those DTCs first. These codes can cause a DTC P0731 to set.

Important: If DTC P0745, P0746, P0756, P0758, P0761, P0763, P0766, P0768, or P0789 is set, diagnose that DTC first. A diagnosed PC solenoid, shift solenoid 2, 3 or 4 low/high circuit fault DTC may have caused DTC P0731 to set.

Important: If any shift solenoid performance DTCs P0781, P0782, or P0783 (2^nd , 3^rd or 4^th gear stuck On) are set, diagnose the highest gear first. A gear stuck On will cause no 1^st gear.

Refer to "Test Section Diagnosis" for pressure apply points and for the following component/location description.

Possible causes of no 1^st gear ratio:

Verify VSS and TRANSMISSION ISS read correctly on Scan tool.

Make sure the pressure control, shift 2, shift 3 and shift 4 solenoids are not intermittently sticking. Sticking solenoids may cause 2^nd , 3^rd or 4^th gear to be applied from an initial start causing no 1^st gear. Audible sound should be similar for all solenoids. A muffled tone indicates the need for replacement.

Important: 1^st gear is a mechanical hydraulic apply. Other than line pressure, there is no electrical circuit for 1^st gear.

The powertrain control module (PCM) uses the crankshaft position (CKP) sensor, input speed sensor (ISS) and output speed sensor (OSS) to determine engine speed, input shaft speed and output shaft speed. These sensor readings are used to determine the current gear ratio and RPM slip across the torque converter. The PCM uses this information from the sensors to determine if the commanded gear matches the actual gear. During normal driving conditions, the PCM will adapt main line pressure via the pressure control (PC) solenoid to prevent slipping and harsh shifts. Shift solenoid 2 is used to apply or release second gear clutch. The PCM controls 2^nd gear by controlling the ground for shift solenoid 2. The PCM will turn the solenoid Off (open the driver circuit) when second gear is commanded On to apply 2^nd clutch. Shift solenoid 2 is supplied ignition voltage from the fuel pump relay whenever the PCM commands the fuel pump relay On. DTC P0732 sets when 2^nd clutch still slips after the PCM has commanded high main line pressure.

DTC P0732 will set if the PCM detects an incorrect actual 2^nd gear ratio when 2^nd gear is commanded On when:

DTC P0732 diagnostic runs continuously once the above conditions have been met.

DTC P0732 is a type A DTC

Important: If DTCs P0745, P0746, P0756, P0758, P0761, P0763, P0766, P0768 or P0789 is set, diagnose that DTC first. A diagnosed PC solenoid, shift solenoid 2, 3 or 4 low/high circuit fault DTC may have caused DTC P0732 to set.

Important: If any shift solenoid performance DTCs P0782 or P0783 3^rd or 4^th gear stuck On) are set, diagnose the highest gear first. A 3^rd or 4^th gear stuck On may cause no 2^nd gear.

Refer to "Test Section Diagnosis" for pressure apply points and for the following component/location description.

Possible causes of no 2^nd gear are listed in the flowchart on the succeeding page.

Verify VSS and TRANSMISSION ISS read correctly on Scan tool.

Make sure the pressure control, shift 2, shift 3 and shift 4 solenoids are not intermittently sticking. Sticking shift solenoid 3 or 4 may cause 3^rd or 4^th gear to be applied from an initial start causing no 2^nd gear. Audible sound should be similar for all solenoids. A muffled tone indicates the need for replacement.

Important: There are different cases and different fwd/rev servo pistons for different model years. Incorrect use of these parts may result in no 2^nd gear.

The powertrain control module (PCM) uses the crankshaft position (CKP) sensor, input speed sensor (ISS) and output speed sensor (OSS) to determine engine speed, input shaft speed and output shaft speed. These sensor readings are used to determine the current gear ratio and RPM slip across the torque converter. The PCM uses this information from the sensors to determine if the commanded gear matches the actual gear. During normal driving conditions, the PCM will adapt main line pressure via the pressure control (PC) solenoid to prevent slipping and harsh shifts. Shift solenoid 3 is used to apply or release third gear clutch. The PCM controls 3^rd gear by controlling the ground for shift solenoid 3. The PCM will turn the solenoid OFF, open the driver circuit, when 3^rd gear is commanded On to apply 3^rd clutch. Shift solenoid 3 is supplied ignition voltage from the fuel pump relay whenever the PCM commands the fuel pump relay ON. DTC P0733 sets when 3^rd clutch still slips after the PCM has commanded high main line pressure.

DTC P0733 will set if the PCM detects an incorrect actual 3^rd gear ratio when 3^rd gear is commanded On when:

DTC P0733 diagnostic runs continuously once the above conditions have been met.

DTC P0733 is a type A DTC

Important: If DTCs P0745, P0746, P0756, P0758, P0761, P0763, P0766, P0768 or P0789 is set, diagnose that DTC first. A diagnosed PC solenoid, shift solenoid 2, 3 or 4 low/high circuit fault DTC may have caused DTC P0733 to set.

Important: If a shift solenoid performance DTC P0783, 4th gear stuck ON, is set, diagnose that DTC first. A 4th gear stuck ON may cause no 3^rd gear, no 2^nd gear, or TCC stuck Off.

Refer to "Test Section Diagnosis" for pressure apply points and for the following component/location description.

Possible causes of no 3^rd gear are listed in the flowchart on the succeeding page.

Verify VSS and TRANSMISSION ISS read correctly on Scan tool.

Make sure the pressure control, shift 2, shift 3 and shift 4 solenoids are not intermittently sticking. A sticking shift solenoid 4 may cause 4^th gear to be applied from an initial start resulting in no 3^rd gear. Audible sound should be similar for all solenoids. A muffled tone indicates the need for replacement.

The powertrain control module (PCM) uses the crankshaft position (CKP) sensor, input speed sensor (ISS) and output speed sensor (OSS) to determine engine speed, input shaft speed and output shaft speed. These sensor readings are used to determine the current gear ratio and RPM slip across the torque converter. The PCM uses this information from the sensors to determine if the commanded gear matches the actual gear. During normal driving conditions, the PCM will adapt main line pressure via the pressure control (PC) solenoid to prevent slipping and harsh shifts. Shift solenoid 4 is used to apply or release 4^th gear clutch. The PCM controls 4^th gear by controlling the ground for shift solenoid 4. The PCM will turn the solenoid OFF, open the driver circuit , when 4^th gear is commanded ON to apply 4^th clutch. Shift solenoid 4 is supplied ignition voltage from the fuel pump relay whenever the PCM commands the fuel pump relay On. DTC P0734 sets when 4^th clutch still slips after the PCM has commanded high main line pressure.

DTC P0734 will set if the PCM detects an incorrect actual 4^th gear ratio when 4^th gear is commanded On when:

DTC P0734 diagnostic runs continuously once the above conditions have been met.

DTC P0734 is a type A DTC

Important: If DTC P0745, P0746, P0756, P0758, P0761, P0763, P0766, P0768 or P0789 is set, diagnose that DTC first. A diagnosed PC solenoid, shift solenoid 2, 3 or 4 low/high circuit fault DTC may have caused DTC P0734 to set.

Refer to "Test Section Diagnosis" for pressure apply points and for the following component/location description.

Possible causes of no 4^th gear are listed in the flowchart on the succeeding page.

Verify VSS and TRANSMISSION ISS read correctly on Scan tool.

Ensure that the pressure control, shift 2, shift 3 and shift 4 solenoids are not intermittently sticking. Audible sound should be similar for all solenoids. A muffled tone indicates the need for replacement.

The torque converter clutch (TCC) solenoid is used to apply and release TCC. The TCC can be applied in all forward gears. The powertrain control module (PCM) controls TCC by pulse width modulating an internal driver that pulls solenoid circuit to ground. When the TCC solenoid is commanded ON, circuit grounded, TCC is applied, which works opposite to all other four transaxle solenoids. The TCC solenoid circuit is monitored for low and high voltage faults. The PCM uses the crankshaft position sensor (CKP) and input speed sensor (ISS) to calculate RPM slip acros torque converter. The PCM will use this information to determine torque converter clutch (TCC) slip. DTC P0741 sets when the TCC solenoid is commanded ON and engine speed does not equal input shaft speed, indicating TCC slip.

DTC P0741 will set if speed difference across torque converter is greater than 280 RPM, indicating TCC stuck OFF when:

DTC P0741 diagnostic runs continuously when the above conditions have been met.

DTC P0741 is a type A DTC

Important: If DTCs P0705, P0706, P0708, P0740, P0743, P0745, or P0789 is set, diagnose that DTC first. A diagnosed TCC solenoid circuit, shift solenoid circuit or low main line pressure DTC may have caused DTC P0741 to set.

Refer to "Test Section Diagnosis" for pressure apply points and for the following component/location description.

Make sure TCC solenoid is not intermittently sticking. Audible sound should be similar for all solenoids. A muffled tone indicates the need for replacement.

An intermittent open anywhere in the circuit or short to voltage on circuit 422 will cause no TCC. Use Scan tool to command TCC SOLENOID ON (PWM) by performing SOLENOID AUDIBLE CHECK. Wiggling wires while performing test may locate a problem.

The TCC will not apply if clutch priority valve is moving to make a shift due to 2nd, 3rd or 4th gear stuck On. DTC P0741 will be set.

The TCC solenoid resistance: 3.8-7.2 ohms

Nominal value: 4.5 ohms at 68°F