For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### DTC Descriptors

DTC P2759: Brake Band Pressure Control Solenoid Valve Control Circuit Shorted
DTC P2762: Brake Band Pressure Control Solenoid Valve Performance
DTC P2763: Brake Band Pressure Control Solenoid Valve Control Circuit Low Voltage
DTC P2764: Brake Band Pressure Control Solenoid Valve Control Circuit High Voltage

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
Signal | P2763 | P2764 | P2764 | P2759, P2762
Low Reference | -- | P2759, P2762, P2764 | P2759, P2762, P2764 | P2759, P2762, P2764

### Typical Scan Tool Data

Circuit | Short to Ground | Open | Short to Voltage
--- | --- | --- | ---
Operating Conditions: Engine running, normal operating temperature Parameter Normal Range: 0.1 A to 1.1 A
Signal | 0 A | 2.55 A | 2.55 A
Low Reference | -- | 2.55 A | 1
1. Internal TCM damage may occur if shorted to B+

### Circuit/System Description

Based on input speed and output speed signals, signals from the engine control module (engine speed and throttle opening) and vehicle speed, smooth lock-up control and slip is performed through the lock-up control solenoid (SLU). The SLU is linearly turned ON and OFF. The lock-up clutch inside the torque converter is operated, and the pump impeller and turbine runner are connected. Through this, the engine and the automatic transmission are coupled and engine output is connected directly to the automatic transmission, eliminating transmission loss. By sliding the lock-up clutch when lock-up is in the OFF range, extends the lock-up range to low vehicle speeds. It also suppresses a rise in engine speed and increases transmission efficiency, improving fuel economy and at the same time, through the sliding of the lockup clutch, engine vibration can be absorbed by the torque converter.

### Conditions for Running the DTC

#### P2759

• | The ignition voltage is between 10.2 V and 15.5 V.

• | The engine speed is greater than 400 RPM for 2 seconds.

• | The transmission is not in emergency mode.

• | Driving in D range.

• | TCM communication is normal.

• | DTCs P2763 and P2764 are not set.

#### P2762

• | The ignition voltage is between 10.2 V and 15.5 V.

• | The engine speed is greater than 400 RPM for 2 seconds.

• | The transmission is not in emergency mode.

• | Driving in D range.

• | TCM communication is normal.

• | The Automatic Transmission Fluid Temperature is more than 20°C (68°F)

• | SLU current is more than 0.85 A.

• | SLU target current is not changed.

#### P2763

• | The ignition voltage is between 10.2 V and 15.5 V.

• | The engine speed is greater than 400 RPM for 2 seconds.

• | The transmission is not in emergency mode.

• | Driving in D range.

• | TCM communication is normal.

• | DTC P2764 is not set.

#### P2764

• | The ignition voltage is between 10.2 V and 15.5 V.

• | The engine speed is greater than 400 RPM for 2 seconds.

• | The transmission is not in emergency mode.

• | Driving in D range.

• | TCM communication is normal.

• | DTC P2763 is not set.

### Conditions for Setting the DTC

#### P2759

Deviation between commanded current and feedback current.

#### P2762

The TCM detects the error current more than 80 mA for 2.75 ms.

#### P2763

The TCM detects at least 5 times less than 23 mA current consumption of the SLU control circuit for 100 ms.

#### P2764

The TCM detects at least 5 times more than 1.333 A current consumption of the SLU control circuit for 100 ms.

### Action Taken When the DTC Sets

#### P2759, P2762

• | DTC P2759 and P2762 are Type B DTC.

• | The TCM turns OFF all solenoids.

• | The TCM allows the vehicle to operate only in second gear and "R" range after a stop.

#### P2763, P2764

• | DTCs P2763 and P2764 are Type B DTCs.

• | No self learning function.

• | The TCM turns OFF all solenoids.

• | The TCM allows the vehicle to operate only in second gear and "R" range after a stop.

### Conditions for Clearing the DIC/DTC

#### P2759, P2762

• | DTC P2759 and P2762 are Type B DTC.

• | The TCM detects the error current less than 50 mA for 2.75 ms.

#### P2763, P2764

• | DTCs P2763 and P2764 are Type B DTCs.

• | The current consumption of the SLU control circuit is between 0.1 A and 1.1 A for 500 ms.

### Diagnostic Aids

When attempting to set solenoid electrical DTCs, ensure the TCM is warmed up and the transmission is operated in 2nd gear long enough to ensure a 3°C (5°F) increase in TCM substrate temperature. This will place the TCM in the optimal condition to test solenoid electrical DTCs.

### Reference Information

#### Schematic Reference

Automatic Transmission Controls Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Description and Operation

Transmission Component and System Description

#### DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ensure the transmission fluid temperature is between 50-80°C (122-176°F).
2. Operate the vehicle in 2nd gear long enough to ensure at least a 3°C (5°F) rise in transmission fluid temperature, then operate the vehicle in Park for 5 s.
3. Observe the scan tool data TCC PC Solenoid Valve Current parameter, the reading should be between 0.1-1.1 A.

### Circuit/System Testing

Command the TCC Solenoid Valve increase and decrease with a scan tool. The value should rise from 0.1 A - 1.1 A and return to 0.1 A.

⇒ | If the value does not change, turn ignition OFF, remove the K71 Transmission Control Module (TCM). Connect a test lamp between the low reference circuit terminal 4 (X2) at the K71 Transmission Control Module (TCM) and the voltage supply component circuit terminal 9 (X2) at the K71 Transmission Control Module (TCM). Command the TCC Solenoid Valve increase and decrease with a scan tool. The test lamp has to illuminate brighter with increasing current.

⇒ | If the test lamp always illuminates or always does not illuminate, replace the K71 Transmission Control Module (TCM).

### Component Testing

#### Static Test

1. Ignition OFF, remove the K71 Transmission Control Module (TCM).
2. Test for 5-5.6 Ω at 20°C (68°F) between the low reference circuit terminal 4 (X2) and the voltage supply circuit terminal 9 (X2).

⇒ | If less than the specified range, test the wiring harness for internal short. If the circuit test normal, replace the Q27C Pressure Control (PC) Solenoid Valve.

3. Test for infinite resistance between each terminal and the low reference circuit terminal 4 (X2) and also to the voltage supply circuit terminal 9 (X2).

⇒ | If less than the specified range, replace the wiring harness.

4. If all circuit test normal, perform the control solenoid valve inspection Control Solenoid Valve Inspection.

⇒ | If the inspection test normal, replace the control valve body.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Control valve body replacement. Refer to Control Valve Body Replacement for replacement, setup and programming.

• | TCM, refer to Control Module References for replacement, setup and programming.

⇒ | Perform the Transmission Adaptive Functions.

• | Wiring harness, refer to Automatic Transmission Wiring Harness Replacement for replacement