LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2012 >> IS 350C >> Repair and Diagnosis >> Transmission >> Automatic Trans >> Automatic Transmission (Diagnostics - Introduction) >> Automatic Transmission System >> Problem Symptoms Table >> Problem Symptoms Table
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Problem Symptoms Table

HINT: 

If a normal code is displayed during the diagnostic trouble code check although the trouble still occurs, check the electrical circuits for each symptom in the order given in the charts on the following information and proceed to information given for troubleshooting.

The Matrix Chart is divided into 2 chapters.

Chapter 1:

Refer to the table below when the trouble cause is considered to be electrical.

If the instruction "Proceed to next circuit inspection shown on matrix chart" is given in the flow chart of each circuit, proceed to the circuit with the next highest number in the table to continue the check.

If the trouble still occurs even though there are no abnormalities in any of the other circuits, check and replace the ECM.

1. CHAPTER 1: ELECTRONIC CIRCUIT MATRIX CHART

Symptom Suspected Area See
No up-shift (1st -> 2nd) 1. Shift solenoid valve (S1) circuit *1 Refer to DTC P0973: Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1); DTC P0974: Shift Solenoid "A" Control Circuit High (Shift Solenoid Valve S1)
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No up-shift (2nd -> 3rd) 1. Shift solenoid valve (S2) circuit *1 Refer to DTC P0976: Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2); DTC P0977: Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No up-shift (3rd -> 4th) 1. Shift solenoid valve (S3) circuit *1 Refer to DTC P0979: Shift Solenoid "C" Control Circuit Low (Shift Solenoid Valve S3); DTC P0980: Shift Solenoid "C" Control Circuit High (Shift Solenoid Valve S3)
2. Engine coolant temp. sensor circuit *1 Refer to DIAGNOSTIC TROUBLE CODE CHART
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No up-shift (4th -> 5th) 1. Shift solenoid valve (S4) circuit *1 Refer to DTC P0982: Shift Solenoid "D" Control Circuit Low (Shift Solenoid Valve S4); DTC P0983: Shift Solenoid "D" Control Circuit High (Shift Solenoid Valve S4)
2. Shift solenoid valve (SR) circuit *1 Refer to DTC P0985: Shift Solenoid "E" Control Circuit Low (Shift Solenoid Valve SR); DTC P0986: Shift Solenoid "E" Control Circuit High (Shift Solenoid Valve SR)
3. Shift solenoid valve (SL1) circuit *1 Refer to DTC P0748: Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1)
4. Shift solenoid valve (SL2) circuit *1 Refer to DTC P0778: Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2)
5. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No up-shift (5th -> 6th) 1. Park/neutral position switch circuit *1 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
2. Engine coolant temp. sensor circuit *1 Refer to DIAGNOSTIC TROUBLE CODE CHART
3. Shift solenoid valve (S2) circuit *1 Refer to DTC P0976: Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2); DTC P0977: Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)
4. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No down-shift (6th -> 5th) 1. Park/neutral position switch circuit *1 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
2. Shift solenoid valve (S2) circuit *1 Refer to DTC P0976: Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2); DTC P0977: Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No down-shift (5th -> 4th) 1. Shift solenoid valve (S4) circuit *1 Refer to DTC P0982: Shift Solenoid "D" Control Circuit Low (Shift Solenoid Valve S4); DTC P0983: Shift Solenoid "D" Control Circuit High (Shift Solenoid Valve S4)
2. Shift solenoid valve (SR) circuit *1 Refer to DTC P0985: Shift Solenoid "E" Control Circuit Low (Shift Solenoid Valve SR); DTC P0986: Shift Solenoid "E" Control Circuit High (Shift Solenoid Valve SR)
3. Shift solenoid valve (SL1) circuit *1 Refer to DTC P0748: Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1)
4. Shift solenoid valve (SL2) circuit *1 Refer to DTC P0778: Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2)
5. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No down-shift (4th -> 3rd) 1. Shift solenoid valve (S3) circuit *1 Refer to DTC P0979: Shift Solenoid "C" Control Circuit Low (Shift Solenoid Valve S3); DTC P0980: Shift Solenoid "C" Control Circuit High (Shift Solenoid Valve S3)
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No down-shift (3rd -> 2nd) 1. Shift solenoid valve (S2) circuit *1 Refer to DTC P0976: Shift Solenoid "B" Control Circuit Low (Shift Solenoid Valve S2); DTC P0977: Shift Solenoid "B" Control Circuit High (Shift Solenoid Valve S2)
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No down-shift (2nd -> 1st) 1. Shift solenoid valve (S1) circuit *1 Refer to DTC P0973: Shift Solenoid "A" Control Circuit Low (Shift Solenoid Valve S1); DTC P0974: Shift Solenoid "A" Control Circuit High (Shift Solenoid Valve S1)
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No lock-up or No lock-up off 1. Shift solenoid valve (SLU) circuit *1 Refer to DTC P2759: Torque Converter Clutch Pressure Control Solenoid Control Circuit Electrical (Shift Solenoid Valve SLU)
2. Stop light switch circuit *1 Refer to DTC P0724: Brake Switch "B" Circuit High
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No lock-up 1. Shift solenoid valve (SLU) circuit *1 Refer to DTC P2759: Torque Converter Clutch Pressure Control Solenoid Control Circuit Electrical (Shift Solenoid Valve SLU)
2. Engine coolant temp. sensor circuit *1 Refer to DIAGNOSTIC TROUBLE CODE CHART
3. Stop light switch circuit *1 Refer to DTC P0724: Brake Switch "B" Circuit High
4. Speed sensor NT circuit *1 Refer to DTC P0717: Turbine Speed Sensor Circuit No Signal
5. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No lock-up off 1. Shift solenoid valve (SLU) circuit *1 Refer to DTC P2759: Torque Converter Clutch Pressure Control Solenoid Control Circuit Electrical (Shift Solenoid Valve SLU)
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Shift point too high or too low 1. Shift solenoid valve (SLT) circuit *1 Refer to DTC P2716: Pressure Control Solenoid "D" Electrical (Shift Solenoid Valve SLT)
2. Speed sensor NT circuit *1 Refer to DTC P0717: Turbine Speed Sensor Circuit No Signal
3. Speed sensor SP2 circuit *1 Refer to DTC P0500: Vehicle Speed Sensor "A"
4. Throttle position sensor circuit *1 Refer to DIAGNOSTIC TROUBLE CODE CHART
5. Pattern select (PWR) switch circuit Refer to Pattern Select Switch Power Mode Circuit
6. ATF temperature sensor circuit *1 Refer to DTC P0712: Transmission Fluid Temperature Sensor "A" Circuit Low Input; DTC P0713: Transmission Fluid Temperature Sensor "A" Circuit High Input
7. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Up-shift to 4th from 3rd while engine is cold 1. Engine coolant temp. sensor circuit *1 Refer to DIAGNOSTIC TROUBLE CODE CHART
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Up-shift to 5th from 4th while engine is cold 1. Engine coolant temp. sensor circuit *1 Refer to DIAGNOSTIC TROUBLE CODE CHART
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No gear change by shifting into "+" or "-" while the shifting lever 1. Transmission control switch circuit Refer to Transmission Control Switch Circuit
2. Shift paddle switch circuit Refer to Shift Paddle Switch Circuit
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Harsh engagement (N -> D) 1. Shift solenoid valve (SLT) circuit *1 Refer to DTC P2716: Pressure Control Solenoid "D" Electrical (Shift Solenoid Valve SLT)
2. Speed sensor NT circuit *1 Refer to DTC P0717: Turbine Speed Sensor Circuit No Signal
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Harsh engagement (Lock-up) 1. Speed sensor NT circuit *1 Refer to DTC P0717: Turbine Speed Sensor Circuit No Signal
2. Speed sensor SP2 circuit *1 Refer to DTC P0500: Vehicle Speed Sensor "A"
3. Shift solenoid valve (SLU) circuit *1 Refer to DTC P2759: Torque Converter Clutch Pressure Control Solenoid Control Circuit Electrical (Shift Solenoid Valve SLU)
4. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Harsh engagement (Any driving position) 1. Throttle position sensor circuit *1 Refer to DIAGNOSTIC TROUBLE CODE CHART
2. Shift solenoid valve (SL1) circuit *1 Refer to DTC P0748: Pressure Control Solenoid "A" Electrical (Shift Solenoid Valve SL1)
3. Shift solenoid valve (SL2) circuit *1 Refer to DTC P0778: Pressure Control Solenoid "B" Electrical (Shift Solenoid Valve SL2)
4. Shift solenoid valve (SLU) circuit *1 Refer to DTC P2759: Torque Converter Clutch Pressure Control Solenoid Control Circuit Electrical (Shift Solenoid Valve SLU)
5. Shift solenoid valve (SLT) circuit *1 Refer to DTC P2716: Pressure Control Solenoid "D" Electrical (Shift Solenoid Valve SLT)
6. Speed sensor NT circuit *1 Refer to DTC P0717: Turbine Speed Sensor Circuit No Signal
7. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Poor acceleration 1. Shift solenoid valve (SLT) circuit *1 Refer to DTC P2716: Pressure Control Solenoid "D" Electrical (Shift Solenoid Valve SLT)
2. Pattern select (SNOW) switch circuit Refer to Pattern Select Switch Snow Mode Circuit
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No engine brake ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
No kick-down ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Engine stalls when starting off or stopping 1. Shift solenoid valve (SLU) circuit *1 Refer to DTC P2759: Torque Converter Clutch Pressure Control Solenoid Control Circuit Electrical (Shift Solenoid Valve SLU)
2. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
ECT SNOW does not operate 1. Shift solenoid valve (SLT) circuit *1 Refer to DTC P2716: Pressure Control Solenoid "D" Electrical (Shift Solenoid Valve SLT)
2. Pattern select (SNOW) switch circuit Refer to Pattern Select Switch Snow Mode Circuit
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Malfunction in shifting 1. Park/neutral position switch circuit *1 Refer to DTC P0705: Transmission Range Sensor Circuit Malfunction (PRNDL Input)
2. Transmission control switch circuit Refer to Transmission Control Switch Circuit
3. ECM Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE
Harsh engagement (1st -> 2nd -> 3rd -> 4th -> 5th) Shift solenoid valve (SR) circuit *1 Refer to DTC P0985: Shift Solenoid "E" Control Circuit Low (Shift Solenoid Valve SR); DTC P0986: Shift Solenoid "E" Control Circuit High (Shift Solenoid Valve SR)
Slip or shudder (5th -> 6th and 6th -> 5th) Shift solenoid valve (SR) circuit *1 Refer to DTC P0985: Shift Solenoid "E" Control Circuit Low (Shift Solenoid Valve SR); DTC P0986: Shift Solenoid "E" Control Circuit High (Shift Solenoid Valve SR)

HINT: 

*1: When the circuit is detective, a DTC may be output.

2. CHAPTER 2: ON-VEHICLE REPAIR AND OFF-VEHICLE REPAIR

Symptom Suspected Area See
Vehicle does not move in any forward position and reverse positions 1. Transmission control rod Refer to ADJUSTMENT
2. Manual valve Refer to COMPONENTS
3. Parking lock pawl Refer to COMPONENTS
4. Rear planetary gear unit Refer to COMPONENTS
5. Torque converter clutch Refer to INSPECTION
Vehicle does not move in R position 1. Valve body assembly Refer to REMOVAL
2. Brake No. 4 (B4) Refer to COMPONENTS
No up-shift (1st -> 2nd) 1. Valve body assembly Refer to REMOVAL
2. Brake No. 3 (B3) Refer to COMPONENTS
3. One-way clutch No. 1 (F1) Refer to COMPONENTS
4. One-way clutch No. 2 (F2) Refer to COMPONENTS
No up-shift (2nd -> 3rd) 1. Valve body assembly Refer to REMOVAL
2. Clutch No. 3 (C3) Refer to COMPONENTS
No up-shift (3rd -> 4th) 1. Valve body assembly Refer to REMOVAL
2. Clutch No. 2 (C2) Refer to COMPONENTS
No up-shift (4th -> 5th) 1. Valve body assembly Refer to REMOVAL
2. Brake No. 1 (B1) Refer to COMPONENTS
No up-shift (5th -> 6th) 1. Valve body assembly Refer to REMOVAL
2. Brake No. 2 (B2) Refer to COMPONENTS
No down-shift (6th -> 5th) Valve body assembly Refer to REMOVAL
No down-shift (5th -> 4th) Valve body assembly Refer to REMOVAL
No down-shift (4th -> 3rd) Valve body assembly Refer to REMOVAL
No down-shift (3rd -> 2nd) Valve body assembly Refer to REMOVAL
No down-shift (2nd -> 1st) Valve body assembly Refer to REMOVAL
No lock-up or No lock-up off 1. Valve body assembly Refer to REMOVAL
2. Torque converter clutch Refer to INSPECTION
Harsh engagement (N -> D) 1. Valve body assembly Refer to REMOVAL
2. C1 accumulator Refer to COMPONENTS
3. Clutch No. 1 (C1) Refer to COMPONENTS
4. One-way clutch No. 3 (F3) Refer to COMPONENTS
5. One-way clutch No. 4 (F4) Refer to COMPONENTS
Harsh engagement (Lock-up) 1. Valve body assembly Refer to REMOVAL
2. Torque converter clutch Refer to INSPECTION
Harsh engagement (N -> R) 1. Valve body assembly Refer to REMOVAL
2. C3 accumulator Refer to COMPONENTS
3. Clutch No. 3 (C3) Refer to COMPONENTS
4. Brake No. 4 (B4) Refer to COMPONENTS
5. One-way clutch No. 1 (F1) Refer to COMPONENTS
Harsh engagement (1st -> 2nd -> 3rd -> 4th -> 5th -> 6th) Valve body assembly Refer to REMOVAL
Harsh engagement (1st -> 2nd) 1. Valve body assembly Refer to REMOVAL
2. B3 accumulator Refer to COMPONENTS
3. Brake No. 3 (B3) Refer to COMPONENTS
4. One-way clutch No. 1 (F1) Refer to COMPONENTS
5. One-way clutch No. 2 (F2) Refer to COMPONENTS
Harsh engagement (2nd -> 3rd) 1. Valve body assembly Refer to REMOVAL
2. C3 accumulator Refer to COMPONENTS
3. Clutch No. 3 (C3) Refer to COMPONENTS
Harsh engagement (3rd -> 4th) 1. Valve body assembly Refer to REMOVAL
2. C2 accumulator Refer to COMPONENTS
3. Clutch No. 2 (C2) Refer to COMPONENTS
Harsh engagement (4th -> 5th) 1. Valve body assembly Refer to REMOVAL
2. B1 accumulator Refer to COMPONENTS
3. Brake No. 1 (B1) Refer to COMPONENTS
Harsh engagement (5th -> 6th) 1. Valve body assembly Refer to REMOVAL
2. B2 accumulator Refer to COMPONENTS
3. Brake No. 2 (B2) Refer to COMPONENTS
Harsh engagement (6th -> 5th) 1. Valve body assembly Refer to REMOVAL
2. C3 accumulator Refer to COMPONENTS
3. Clutch No. 3 (C3) Refer to COMPONENTS
Slip or shudder (Forward and reverse: After warm-up) 1. Valve body assembly Refer to REMOVAL
2. Oil strainer Refer to REMOVAL
3. One-way clutch No. 1 (F1) Refer to COMPONENTS
4. Clutch No. 3 (C3) Refer to COMPONENTS
5. Torque converter clutch Refer to INSPECTION
Slip or shudder (Particular position: Just after engine starts) Torque converter clutch Refer to INSPECTION
Slip or shudder (R position) 1. Brake No. 4 (B4) Refer to COMPONENTS
2. One-way clutch No. 1 (F1) Refer to COMPONENTS
3. Clutch No. 3 (C3) Refer to COMPONENTS
Slip or shudder (1st) 1. Clutch No. 1 (C1) Refer to COMPONENTS
2. One-way clutch No. 3 (F3) Refer to COMPONENTS
3. One-way clutch No. 4 (F4) Refer to COMPONENTS
Slip or shudder (2nd) 1. Clutch No. 1 (C1) Refer to COMPONENTS
2. Brake No. 3 (B3) Refer to COMPONENTS
3. One-way clutch No. 1 (F1) Refer to COMPONENTS
4. One-way clutch No. 2 (F2) Refer to COMPONENTS
5. One-way clutch No. 4 (F4) Refer to COMPONENTS
Slip or shudder (3rd) 1. Clutch No. 1 (C1) Refer to COMPONENTS
2. Clutch No. 3 (C3) Refer to COMPONENTS
3. One-way clutch No. 1 (F1) Refer to COMPONENTS
4. One-way clutch No. 4 (F4) Refer to COMPONENTS
Slip or shudder (4th) 1. Clutch No. 1 (C1) Refer to COMPONENTS
2. Clutch No. 2 (C2) Refer to COMPONENTS
3. One-way clutch No. 4 (F4) Refer to COMPONENTS
Slip or shudder (5th) 1. Clutch No. 2 (C2) Refer to COMPONENTS
2. Clutch No. 3 (C3) Refer to COMPONENTS
3. Brake No. 1 (B1) Refer to COMPONENTS
Slip or shudder (6th) 1. Clutch No. 2 (C2) Refer to COMPONENTS
2. Brake No. 2 (B2) Refer to COMPONENTS
No engine braking (1st +- 4th: S position) Clutch No. 4 (C4) Refer to COMPONENTS
No engine braking (1st: 1 position) 1. Valve body assembly Refer to REMOVAL
2. Brake No. 4 (B4) Refer to COMPONENTS
No engine braking (2nd: 2 position) 1. Valve body assembly Refer to REMOVAL
2. Brake No. 2 (B2) Refer to COMPONENTS
No engine braking (3rd: 3 position) 1. Valve body assembly Refer to REMOVAL
2. Brake No. 1 (B1) Refer to COMPONENTS
No engine braking (4th: 4 position) Valve body assembly Refer to REMOVAL
No kick-down Valve body assembly Refer to REMOVAL
Shift point too high or too low Valve body assembly Refer to REMOVAL
Poor acceleration (All positions) 1. Valve body assembly Refer to REMOVAL
2. Torque converter clutch Refer to INSPECTION
Poor acceleration (6th) 1. Brake No. 2 (B2) Refer to COMPONENTS
2. Clutch No. 2 (C2) Refer to COMPONENTS
3. Front planetary gear unit Refer to COMPONENTS
Engine stalls when starting off or stopping 1. Valve body assembly Refer to REMOVAL
2. Torque converter clutch Refer to INSPECTION
scientia non olet · About LEMON Manuals