Automatic Transaxle Diagnosis - 4t40-e & 4t45-e Chevrolet Malibu V рестайлинг

APPLICATION

TRANSAXLE APPLICATION

Transaxle has a metal identification plate attached to rear face of transaxle case. (Scheme 50)

Scheme 50

DESCRIPTION & OPERATION

Note. For additional information on transaxle operation, see appropriate OVERHAUL article.

INTRODUCTION

The 4T40-E/4T45-E is a fully automatic front wheel drive electronically controlled transaxle. The transaxle provides four forward ranges including overdrive and one reverse gear range. The Powertrain Control Module (PCM) controls shift points by means of two shift solenoids. A vane type pump supplies the oil pressure. The PCM regulates oil pressure by means of the Pressure Control (PC) solenoid.

You can operate the transaxle in any one of the following seven modes

1. P - Park position prevents the vehicle from rolling either forward or backward. For safety reasons, use the parking brake in addition to the Park position.
2. R - Reverse allows the vehicle to be operated in a rearward direction.
3. N - Neutral allows the engine to be started and operated while driving the vehicle. If necessary, you may select this position to restart the engine with the vehicle moving.
4. D - Overdrive is used for all normal driving conditions. Overdrive provides four gear ratios plus a converter clutch operation. Depress the accelerator to downshift for safe passing.
5. 3 - Drive position is used for city traffic and hilly terrain. Drive provides three gear ranges, and drive range prevents the transaxle from operating in 4th gear. Depress the accelerator to downshift.
6. 2 - Manual 2nd provides two gear ratios under most operating conditions. Manual 2nd provides acceleration and engine braking. Select this range at any vehicle speed, but the transaxle will not downshift into 2nd gear until the vehicle speed drops below approximately 62 MPH.
7. 1 - Manual Low provides maximum engine braking. You may also select this range at any vehicle speed, but the transaxle will not downshift into 1st gear until the vehicle speed drops below approximately 37 MPH.

TRANSAXLE COMPONENTS & SYSTEMS

Note. For transaxle electronic component locations (Scheme 51)

The mechanical components of this unit are as follows

1. A torque converter with a Torque Converter Clutch (TCC).
2. A drive link assembly.
3. Intermediate-4th and low-reverse friction band assemblies.
4. Forward, coast, 2nd, reverse, and direct multiple disc clutch assemblies.
5. Two planetary gear sets: input and reaction.
6. Two roller clutches: low and 2nd.
7. One sprag clutch.
8. One vane type oil pump.
9. One control valve assembly.
10. A final drive and differential assembly.

The electrical components of this unit are as follows

1. Two shift solenoid valves: 1-2 and 2-3.
2. A Torque Converter Clutch Pulse Width Modulated (TCC PWM) solenoid valve.
3. A Pressure Control (PC) solenoid valve.
4. A Transmission Fluid Temperature (TFT) sensor.
5. Two speed sensors: input and output speed sensor.
6. A Transmission Fluid Pressure (TFP) manual valve position switch assembly.
7. A transaxle internal wiring harness assembly.
8. A Park/Neutral Position (PNP) switch.

Scheme 51

Torque Converter Clutch Pulse Width Modulated Solenoid Valve

The Torque Converter Clutch (TCC) solenoid valve is a normally closed, Pulse Width Modulated (PWM) solenoid used to control the apply and release of the converter clutch. The PCM operates the solenoid with a negative duty cycle at a fixed frequency of 42 Hz to control the rate of TCC apply and release. The solenoid's ability to ramp the TCC apply and release pressures results in smoother TCC operation.

When vehicle operating conditions are appropriate to apply the TCC, the PCM immediately increases the duty cycle to about 42 percent. The PCM then ramps the duty cycle up to about 90 percent to achieve full TCC apply pressure. The rate at which the PCM increases the duty cycle controls the TCC apply. Similarly, the PCM also ramps down the TCC solenoid duty cycle to control the TCC release.

Some operating conditions prevent or enable the TCC apply under various conditions. Also if the PCM receives a high voltage signal from the brake switch, indicating that the brake pedal is depressed, the PCM immediately releases the TCC.

Pressure Control Solenoid Valve

The Pressure Control (PC) solenoid valve is a precision electronic pressure regulator that controls the line pressure. This control is based on the flow of current through the coil windings of the valve. As the flow of current is increased, the magnetic field which is produced by the coil moves the solenoid's plunger further away from the exhaust port. Opening the exhaust port decreases the output fluid pressure regulated by the PC solenoid valve, which ultimately decreases line pressure.

The PCM controls the PC solenoid valve based on various inputs, including throttle position, fluid temperature, MAP sensor, and gear state.

The PCM controls the PC solenoid valve on a positive duty cycle at a fixed frequency of 614 Hz. Duty cycle is defined as the percent of time current is flowing through the solenoid coil during each cycle. A higher duty cycle provides a greater current flow through the solenoid. The high, positive, side of the PC solenoid valve electrical circuit at the PCM controls the PC solenoid valve operation. The PCM provides a ground path for the circuit, monitors average current and continuously varies the PC solenoid valve duty cycle to maintain the correct average current flowing through the PC solenoid valve. See PC SOLENOID VALVE DUTY CYCLE table.

PC SOLENOID VALVE DUTY CYCLE

1-2 & 2-3 Shift Solenoid Valves

The shift solenoid valves are two identical, electronic exhaust valves that control upshifts and downshifts in all forward gear ranges. These valves are normally open. The shift solenoid valves work together in a combination of on and off sequences to control the positions of the 1-2, 2-3, and 3-4 shift valve trains. The PCM monitors numerous inputs to determine the appropriate solenoid state combination and transaxle gear for the vehicle operating conditions.

The PCM energizes the shift solenoid valves by providing a ground to the solenoid's electrical circuit. This sends current through the coil winding of the solenoid, thereby creating a magnetic field. The magnetic field repels the plunger inside the solenoid. This seats the solenoid metering ball against the fluid inlet port. This action prevents the exhaust of fluid through the solenoid. It then provides an increase in fluid pressure at the end of the shift valves. This fluid pressure initiates an upshift by moving the shift valves.

The shift solenoid valves should energize when the voltage is greater than 7.5 volts and de-energize when the voltage is less than one volt.

SHIFT SOLENOID OPERATION

Transmission Fluid Pressure Manual Valve Position Switch Assembly

The Transmission Fluid Pressure (TFP) manual valve position switch assembly is attached to the control valve body. This assembly contains six fluid pressure switches and the transmission fluid temperature sensor.

Five of the fluid pressure switches are normally open. These are used to indicate the position of the manual valve. The PCM uses this information to control line pressure, TCC apply and release, and shift solenoid operation.

The release pressure switch is used as a diagnostic tool to confirm that the TCC is actually off when it has been commanded off by the PCM. This switch is normally closed.

Each fluid pressure switch produces either an open or a ground to the PCM depending on the presence of fluid pressure at the switches. The sequence of open and closed switches produces a combination of voltage readings. The PCM monitors these readings.

The PCM measures TFP manual valve position switch signal voltage from each pin to ground, and compares the voltage to a TFP manual valve position switch combination table stored in the PCM memory. If the PCM does not recognize the switch sequence, a Diagnostic Trouble Code (DTC) will be set as a result. A DTC may also set if the TFP manual valve position switch sequence indicates a gear range selection that conflicts with other sensory inputs to the PCM.

Valid combinations for circuits "A", "B", and "C" are shown in the table. LOW means that the switch is grounded with a resistance less than 50 ohms at zero volts; HI means that the switch is open with a resistance greater than 50 k/ohms at 12 volts. See TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC table.

Resistance of switch should be measured with the engine running. When the transaxle's pass through connector is disconnected from the vehicle harness while the engine is running, multiple DTCs will set. Clear these DTCs when you are finished with this procedure.

TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC

Vehicle Speed Sensor

The Output Speed Sensor (OSS) is a magnetic inductive pickup that relays information relative to vehicle speed to the PCM. Vehicle speed information is used by the PCM to control shift timing, line pressure, and TCC apply and release.

The OSS mounts in the case at the speed sensor rotor which is pressed onto the differential. An air gap of 0.011-0.062" (0.27-1.57 mm) is maintained between the sensor and the teeth on the speed sensor rotor. The sensor consists of a permanent magnet surrounded by a coil of wire. As the differential rotates, an AC signal is induced in the OSS. Higher vehicle speeds induce a higher frequency and voltage measurement at the sensor.

Input Speed Sensor

The Input Speed Sensor (ISS) is a magnetic inductive pickup that relays information about the transaxle input speed to the PCM. The PCM uses this information to control the line pressure, TCC apply and release, and the transaxle shift patterns. This information is also used to calculate the appropriate operating gear ratios and TCC slippage.

The ISS mounts on the transaxle case under the channel plate next to the drive sprocket. An air gap of 0.010-0.114" (0.26-2.90 mm) is maintained between the sensor and the teeth of the drive sprocket. The sensor consists of a permanent magnet surrounded by a coil of wire. As the drive sprocket is driven by the turbine shaft, an AC signal is induced in the ISS. Higher engine speeds induce a higher frequency and voltage measurement at the sensor.

Transmission Fluid Temperature Sensor

The Transmission Fluid Temperature (TFT) sensor is a negative temperature coefficient thermistor that provides information to the PCM regarding transmission fluid temperature. The TFT sensor is integrated in the TFP manual valve position switch assembly which is bolted to the control valve body. The sensor monitors main line pressure from the inside of the control valve body to determine the operating temperature of the transmission fluid. The sensor uses an "O" ring seal to maintain fluid pressure in the control valve body.

The internal electrical resistance of the sensor varies in relation to the operating temperature of the transmission fluid. The PCM sends a 5-volt reference signal to the sensor. This measures the voltage drop in the electrical circuit. A lower fluid temperature creates a higher resistance in the TFT sensor, thereby measuring a higher voltage signal.

The PCM measures this voltage as another input to help control line pressure, shift schedules and TCC apply. When the transmission fluid temperature reaches 284°F (140°C), the PCM enters hot mode. Above this temperature, the PCM modifies the shift schedules and TCC apply in an attempt to reduce fluid temperature by reducing the amount of heat generated by the transaxle. During hot mode, the PCM applies TCC at all times in 3rd and 4th gears. Also, the PCM performs the 2-3 and the 3-4 shifts earlier to help reduce the generation of fluid heat. (Scheme 97)

Park/Neutral Position Switch

The Transaxle Range (TR) switch is part of the Park/Neutral Position (PNP) and back-up lamp switch assembly, which is externally mounted on the transaxle manual shaft. The TR switch contains four internal switches that indicate the gearshift lever position. The PCM supplies ignition voltage to each switch circuit. By grounding one or more of the switch circuits, the PCM detects the selected gear range by the state change of the switch input. See TRANSAXLE RANGE SWITCH LOGIC table.

TRANSAXLE RANGE SWITCH LOGIC (1)

Transaxle Electrical Connector

The transaxle electrical connector is an important part of the transaxle operating system. Any interference with the electrical connection can cause the transaxle to set Diagnostic Trouble Codes (DTC) or affect proper operation.

The following items can affect the electrical connection

1. Bent pins in the connector from rough handling during connection and disconnection.
2. Wires backing away from the pins or coming uncrimped (in either the internal or the external wiring harness).
3. Dirt contamination entering the connector when disconnected.
4. Pins in the internal wiring connector backing out of the connector or pushed out of the connector during reconnection.
5. Excessive transmission fluid leaking into the connector, wicking up into the external wiring harness and degrading the wire insulation.
6. Moisture intrusion in the connector.
7. Low pin retention in the external connector from excessive connection and disconnection of the wiring connector assembly.
8. Pin corrosion from contamination.
9. Damaged connector assembly.

Remember the following points

1. To remove the connector, squeeze the two tabs toward each other and pull straight up without pulling by the wires.
2. Limit twisting or wiggling the connector during removal. Bent pins can occur.
3. Do not pry the connector off with a screwdriver or other tool.
4. Visually inspect the seals to ensure that they are not damaged during handling.
5. To reinstall the external wiring connector, first orient the pins by lining up the arrows on each half of the connector. Push the connector straight down into the transaxle without twisting or angling the mating parts.
6. The connector should click into place with a positive feel and/or noise.
7. Whenever the transaxle external wiring connector is disconnected from the internal harness and the engine is operating, DTCs will set. Clear these DTCs after reconnecting the external connector.

ELECTRONIC CONTROL SYSTEM

PCM constantly monitors all electrical circuits. If PCM detects circuit faults or sensors out of range, it will record a Diagnostic Trouble Code (DTC). If fault continues for a predetermined time, Malfunction Indicator Light (MIL) will illuminate.

If MIL is on all the time, DTC(s) are currently being detected. If MIL is off, but PCM had detected a circuit or sensor fault, DTC(s) will be stored in computer memory.

Stored DTCs may be retrieved from PCM memory using a scan tool. DTCs CANNOT be retrieved by grounding 16-pin Data Link Connector (DLC).

Note. Faulty engine sensors and actuators may cause transaxle related DTCs or driveability problems. Engine faults and related DTCs must be diagnosed and repaired before transaxle DTCs are repaired. For additional information on diagnosing and repairing engine related PCM DTCs, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

POWERTRAIN CONTROL MODULE

On"J" body models, PCM is located forward of right front wheel housing, behind front fascia cavity splash shield. On "N" body models, PCM is located below left side of instrument panel, near steering column. PCM utilizes two harness connectors. See CONNECTOR IDENTIFICATION . PCM controls ignition, fuel and emission devices related to engine and transaxle upshifts and downshifts.

PCM receives electronic signals from sensors and switches. These signals help PCM determine when to operate various relays and solenoids related to engine and transaxle control.

LIMP-IN MODE

If sensor input signals are missing or inadequate for transaxle operation, PCM will output preset operating signals to transaxle. Limp-in mode will keep vehicle operational and allow it to be driven with reduced transaxle function and performance, to a repair facility. Malfunction Indicator Light (MIL) will illuminate if malfunction occurs. Vehicle should not be driven for extended periods in limp-in mode.

SHIFT INTERLOCK SYSTEM

Note. For system description and repair information, see appropriate SHIFT INTERLOCK SYSTEMS article.

TROUBLE SHOOTING

Note. Any diagnosis should begin with confirming the customer's complaint. If possible, road test vehicle first, and note transaxle performance for future reference during diagnosis.

PRELIMINARY INSPECTION

Transaxle malfunctions may be caused by poor engine performance, improper adjustments or failure of hydraulic, mechanical or electronic components. Prior to diagnosing transaxle concerns, always begin by checking fluid level, fluid condition and shift cable adjustment. Ensure engine starts with gearshift lever in Park and Neutral to ensure proper adjustment of park/neutral position switch. Ensure all system-related fuses are okay. Check wire harnesses for proper routing. Verify all harness and component connections are clean and tight. See WIRING DIAGRAMS . If area of fault cannot be located or repaired during preliminary inspection, check self-diagnostic system. See SELF-DIAGNOSTIC SYSTEM . Repair as necessary.

Perform road test to determine if problem has been corrected. See ROAD TEST under PERFORMANCE TESTS. If problem still exists, diagnose by symptom. See SYMPTOM DIAGNOSIS .

SYMPTOM DIAGNOSIS

Note. Perform PRELIMINARY INSPECTION prior to diagnosing by symptom.

Note. Use the following symptoms to aid in preliminary diagnosis. (Scheme 52)- (Scheme 88). If a listed symptom matches the customer's concern, check the applicable items for possible cause.

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CLUTCH & BAND APPLICATIONS

CLUTCH & BAND APPLICATIONS

PERFORMANCE TESTS

Note. Adaptive parameters should be reset if one of the following repairs have been performed: Transaxle replacement. Replacement of any line pressure actuator. Transaxle overhaul when new clutch plates are installed. Replacing control valve body. To reset adaptive parameters, connect scan tool to Data Link Connector (DLC). Follow prompts on scan tool.

The following test provides a method of evaluating the condition of the automatic transaxle. The test is structured so that most driving conditions would be achieved. The test is divided into the following parts

1. Electrical Function Check
2. Upshift Control and Torque Converter Clutch (TCC) Apply
3. Part Throttle Detent Downshifts
4. Full Throttle Detent Downshifts
5. Manual Downshifts
6. Coasting Downshifts
7. Manual Gear Range Selection

Before the road test, ensure the following

1. The engine is performing properly.
2. Transmission fluid level is correct.
3. Tire pressure is correct.

During the road test

1. Perform the test only when traffic conditions permit.
2. Operate the vehicle in a controlled, safe manner.
3. Observe all traffic regulations.
4. View the scan tool data while conducting this test. Take along qualified help to operate the vehicle safely.
5. Observe any unusual sounds or smells.

After the road test, check the following

1. DTCs that may have set during the testing.
2. Scan tool data for any abnormal readings or data.

Electrical Function Check

Note. If any of the following checks do not perform properly, record the result for reference after completion of the road test.

Perform this check first, to ensure the electronic transaxle components are connected and functioning properly. If these components are not checked, a simple electrical condition could be mis-diagnosed.

1. Connect the scan tool.
2. Ensure the gearshift lever is in Park and set the parking brake.
3. Start the engine.
4. Verify that the following scan tool data can be obtained and is functioning properly. Data that is questionable may indicate a concern. Engine Speed Transaxle Input Speed (Turbine) Transaxle Output Speed Vehicle Speed Transmission Fluid Pressure (TFP) Manual Valve Position Switch Transaxle Range Commanded Gear (current gear) Pressure Control (PC) Solenoid Reference Current PC Solenoid Actual Current PC Solenoid Duty Cycle Brake Switch Engine Coolant Temperature Transmission Fluid Temperature Throttle Angle Ignition Voltage 1-2 Shift Solenoid 2-3 Shift Solenoid TCC Solenoid Duty Cycle TCC Slip Speed
5. Monitor the brake switch signal while depressing and releasing the brake pedal. The scan tool should display: Closed when the brake pedal is released. Open when the brake pedal is depressed.
6. Harsh engagement may be caused by any of the following conditions: High idle speed. Compare engine idle speed to desired idle speed. Commanded low PC solenoid current. Compare PC solenoid reference current to PC solenoid actual current. A default condition caused by certain DTCs that result in maximum line pressure to prevent slippage.
7. Soft or delayed engagement may be caused by any of the following conditions: Low idle speed. Compare engine idle speed to desired idle speed. Low transmission fluid level. Commanded high PC solenoid current. Compare PC solenoid reference current to PC solenoid actual current. Cold transmission fluid. Check for low transmission fluid temperature.
8. Check the garage shifts. Apply the brake pedal and ensure the parking brake is set. Move the gearshift lever through the following ranges: Park to Reverse, Reverse to Neutral, Neutral to Drive. Pause 2 to 3 seconds in each gear position. Verify the gear engagements are immediate and not harsh.
9. Monitor transaxle range on the scan tool. Apply the brake pedal and ensure the parking brake is set. Move the gearshift lever through all ranges. Pause 2-3 seconds in each range. Return gearshift lever to Park. Verify that all selector positions match the scan tool display.
10. Check throttle angle input. Apply the brake pedal and ensure the parking brake is set. Ensure the gearshift lever is in Park. Monitor throttle angle while increasing and decreasing engine speed with the throttle pedal. The scan tool throttle angle should increase and decrease with engine speed.

Upshift Control & Torque Converter Clutch Apply

The PCM calculates the upshift points based primarily on two inputs: throttle angle and vehicle speed. When the PCM determines that conditions are met for a shift to occur, the PCM commands the shift by closing or opening the ground circuit for the appropriate solenoid.

1. Choose a throttle position of 12, 25 or 50 percent. See «SHIFT SPEED SPECIFICATIONS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . All throttle angles shown should be tested to cover the normal driving range.
2. Monitor the following scan tool parameters: Throttle Angle Vehicle Speed Engine Speed Commanded Gear Slip Speed Solenoid States
3. Place the gearshift lever in the "D" (Overdrive) position.
4. Accelerate the vehicle using the chosen throttle angle. Hold the throttle steady.
5. As the transaxle upshifts, note the vehicle speed when the shift occurs for each gear change. There should be a noticeable shift feel or engine speed change within 1 to 2 seconds of the commanded gear change.
6. Compare the shift speeds to the shift speed chart. See «SHIFT SPEED SPECIFICATIONS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . Shift speeds may vary slightly due to transmission fluid temperature or hydraulic delays in responding to electronic controls. Note any harsh, soft or delayed shifts or slipping. Note any noise or vibration.
7. Repeat steps 1 - 6 to complete all throttle angles.
8. Check for TCC apply in 3rd and 4th gear. Note the TCC apply point. When the TCC applies, there should be a noticeable drop in engine speed and a drop in slip speed to below 100 RPM. If the TCC apply can not be detected, check for DTCs. For TCC apply speeds, see «SHIFT SPEED SPECIFICATIONS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . Lightly tap and release the brake pedal. The TCC will release on most applications.

Part Throttle Detent Downshift

1. Place the gearshift lever in the "D" (Overdrive) position.
2. Accelerate the vehicle to 40-55 MPH in 4th gear.
3. Quickly increase throttle angle to greater than 50 percent.
4. Verify the following: The TCC releases. The transaxle downshifts immediately to 3rd gear.

Full Throttle Detent Downshift

1. Place the gearshift lever in the "D" (Overdrive) position.
2. Accelerate the vehicle to speeds of 40-55 MPH in 4th gear.
3. Quickly increase throttle angle to 100 percent (WOT).
4. Verify the following: The TCC releases. The transaxle downshifts immediately to 2nd gear.

Manual Downshifts

The shift solenoid valves do not control the 4-3 manual downshift. The 4-3 manual downshift is hydraulic. The 3-2 and 2-1 manual downshifts are electronic. The solenoid states will change during or shortly after a 4-3 downshift is selected.

Manual 4-3 Downshift

Place the gearshift lever in the "D" (Overdrive) position. Accelerate the vehicle to 40-55 MPH in 4th gear. Release the throttle while moving the gearshift lever to 3rd. Verify the following

1. The TCC releases.
2. The transaxle downshifts immediately to 3rd gear.
3. The engine slows the vehicle.

Manual 4-2 Downshift

Place the gearshift lever in the "D" (Overdrive) position. Accelerate the vehicle to 40-45 MPH. Release the throttle while moving the gearshift lever to 2nd. Verify the following

1. The TCC releases.
2. The transaxle downshifts immediately to 2nd gear.
3. The engine slows the vehicle.

Manual 4-1 Downshift

Place the gearshift lever in the "D" (Overdrive) position. Accelerate the vehicle to 40 MPH. Release the throttle while moving the gearshift lever to 1st. Verify the following

1. The TCC releases.
2. The transaxle downshifts immediately to 2nd gear.
3. The engine slows the vehicle.
4. The transaxle downshifts to 1st gear at the calibrated speed, typically 30-40 MPH.

Coasting Downshifts

1. Place the gearshift lever in the "D" (Overdrive) position.
2. Accelerate the vehicle to 4th gear with the TCC applied.
3. Release the throttle and lightly apply the brakes.
4. Verify the following: The TCC releases. Downshifts occur at speeds shown in the shift speed chart. See «SHIFT SPEED SPECIFICATIONS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .

Manual Gear Range Selection

Note. Perform the following manual selection tests using 10-15 percent throttle angle.

The shift solenoids control the upshifts in the manual gear ranges.

Reverse

With the vehicle stopped, move the gearshift lever to Reverse. Slowly accelerate the vehicle. Verify that there is no noticeable slip, noise or vibration.

Manual 1st

With the vehicle stopped, move the gearshift lever to 1st. Accelerate the vehicle to 20 MPH. Verify the following

1. No upshifts occur.
2. The TCC does not apply.
3. There is no noticeable slip, noise or vibration.

Manual 2nd

With the vehicle stopped, move the gearshift lever to 2nd. Accelerate the vehicle to 35 MPH. Verify the following

1. The 1-2 shift occurs.
2. The 2-3 shift does not occur.
3. There is no noticeable slip, noise or vibration.

Manual 3rd

With the vehicle stopped, move the gearshift lever to 3rd. Accelerate the vehicle to 40 MPH. Verify the following

1. The 1-2 shift occurs.
2. The 2-3 shift occurs.
3. There is no noticeable slip, noise or vibration.

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TORQUE CONVERTER DIAGNOSIS

The Torque Converter Clutch (TCC) is applied by fluid pressure, which is controlled by a Pulse Width Modulation (PWM) solenoid valve. This solenoid valve is located inside of the automatic transaxle assembly. The solenoid valve is controlled through a combination of computer controlled switches and sensors.

Torque Converter Stator

The torque converter stator roller clutch can have two different malfunctions

1. The stator assembly freewheels in both directions.
2. The stator assembly remains locked up at all times.

Poor Acceleration At Low Speed

If the stator is freewheeling at all times, the car tends to have poor acceleration from a standstill. At speeds above 30-35 MPH, the car may act normally. For poor acceleration, you should first determine that the exhaust system is not blocked, and the transaxle is in 1st gear when starting out.

If the engine freely accelerates to high RPM in Neutral, you can assume that the engine and the exhaust system are normal. Check for poor performance in Drive and Reverse to help determine if the stator is freewheeling at all times.

Poor Acceleration At High Speed

If the stator is locked up at all times, performance is normal when accelerating from a standstill. Engine RPM and car speed are limited or restricted at high speeds. Visual examination of the converter may reveal a blue color from overheating.

If the converter has been removed, you can check the stator roller clutch by inserting a finger into the splined inner race of the roller clutch and trying to turn the race in both directions. You should be able to freely turn the inner race clockwise, but you should have difficulty in moving the inner race counterclockwise or you may be unable to move the race at all.

Noise

Note. Do not confuse this noise with pump whine noise, which is usually noticeable in Park, Neutral and all other gear ranges. Pump whine will vary with line pressure.

You may notice a torque converter whine when the vehicle is stopped and the transaxle is in Drive or Reverse. This noise will increase as you increase the engine RPM. The noise will stop when the vehicle is moving or when you apply the torque converter clutch, because both halves of the converter are turning at the same speed.

Perform a stall test to make sure the noise is actually coming from the converter

1. Place your foot on the brake.
2. Put the gear selector in Drive.
3. Depress the accelerator to approximately 1200 RPM for no more than 6 seconds.

A torque converter noise will increase under this load.

Torque Converter Clutch Shudder

The key to diagnosing TCC shudder is to note when it happens and under what conditions.

TCC shudder which is caused by the transaxle should only occur during the apply or the release of the converter clutch. Shudder should never occur after the TCC plate is fully applied.

If the shudder occurs while the TCC is applying, the problem can be within the transaxle or the torque converter. Something is causing one of the following conditions to occur

1. Something is not allowing the clutch to become fully engaged.
2. Something is not allowing the clutch to release.
3. The clutch is releasing and applying at the same time.

One of the following conditions may be causing the problem to occur

1. Leaking turbine shaft seals.
2. A restricted release orifice.
3. A distorted clutch or housing surface due to long converter bolts.
4. Defective friction material on the TCC plate.

If Shudder Occurs After TCC Has Applied

If shudder occurs after the TCC has applied, most of the time there is nothing wrong with the transaxle.

As mentioned above, the TCC is not likely to slip after the TCC has been applied. Engine problems may go unnoticed under light throttle and load, but they become noticeable after the TCC apply when going up a hill or accelerating. This is due to the mechanical coupling between the engine and the transaxle.

Once TCC is applied, there is no torque converter (fluid coupling) assistance. Engine or driveline vibrations could be unnoticeable before TCC engagement.

Inspect the following components in order to avoid misdiagnosis of TCC shudder. An inspection will also avoid the unnecessary disassembly of a transaxle or the unnecessary replacement of a torque converter.

1. Spark Plugs - Inspect for cracks, high resistance or a broken insulator.
2. Plug Wires - Look in each end. If there is red dust (ozone) or a black substance (carbon) present, then the wires are bad. Also look for a white discoloration of the wire. This indicates arcing during hard acceleration.
3. Coil - Look for a black discoloration on the bottom of the coil. This indicates arcing while the engine is misfiring.
4. Fuel Injector - The filter may be plugged.
5. Vacuum Leak - The engine will not get a correct amount of fuel. The mixture may run rich or lean depending on where the leak occurs.
6. EGR Valve - The valve may let in too much or too little unburnable exhaust gas, and could cause the engine to run rich or lean.
7. MAP/MAF Sensor - Like a vacuum leak, the engine will not get the correct amount of fuel for proper engine operation.
8. Carbon On The Intake Valves - Carbon restricts the proper flow of air/fuel mixture into the cylinders.
9. Flat Cam - Valves do not open enough to let the proper fuel/air mixture into the cylinders.
10. Oxygen Sensor - This sensor may command the engine too rich or too lean for too long.
11. Fuel Pressure - This may be too low.
12. Engine Mounts - Vibration of the mounts can be multiplied by TCC engagement.
13. Axle Joints - Check for vibration.
14. TP Sensor - The TCC apply and release depends on the TP sensor in many engines. If the TP sensor is out of specification, TCC may remain applied during initial engine loading.
15. Cylinder Balance - Bad piston rings or poorly sealing valves can cause low power in a cylinder.
16. Fuel Contamination - This causes poor engine performance.

HYDRAULIC PRESSURE TESTS

Note. Before performing a line pressure check, verify that the pressure control solenoid valve is receiving the correct electrical signal from the PCM.

Note. Scan tool is only able to control pressure control solenoid in Park and Neutral with vehicle stopped. This protects clutches from extremely high or low pressures in Reverse and Drive.

Line Pressure

1. Install a scan tool.
2. Start the engine and set the parking brake.
3. Check for a stored Diagnostic Trouble Code (DTC). See «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
4. Repair the vehicle, if necessary.
5. Check the transmission fluid level. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
6. Check the manual linkage for proper adjustment. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
7. Turn the engine off. Remove the oil pressure test hole plug and install the pressure gauge. (Scheme 94)
8. Place the gearshift lever in Park and set the parking brake.
9. Start the engine and allow the engine to warm up at idle.
10. Access the Pressure Control (PC) solenoid valve control test on the scan tool.
11. Increase the PC solenoid actual current from zero to one amp in 0.1 amp increments. Allow the pressure to stabilize for five seconds after each pressure change. Read the corresponding line pressure on the pressure gauge.
12. Compare the data to the table. See «LINE PRESSURE SPECIFICATIONS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) table.
13. If pressure readings differ greatly from the table, see «SYMPTOM DIAGNOSIS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e__symptom-diagnosis) under TROUBLE SHOOTING.
14. Shut the engine off. Remove the pressure gauge.
15. Apply sealant (GM P/N 12345382) to the oil pressure test hole plug.
16. Install the oil pressure test hole plug. Tighten the plug to 106 INCH lbs. (12 N.m).

LINE PRESSURE SPECIFICATIONS

Scheme 94

CLUTCH & SERVO AIR CHECKS

Note. For additional information, refer to overhaul procedures. See appropriate OVERHAUL article.

Circuit Description

The diagnostic system check is an organized approach to identify a condition created by an automatic transaxle. The diagnostic system check is the diagnostic starting point for an automatic transaxle complaint. The diagnostic system check directs you to the next logical step for diagnosing a transaxle concern. Perform this check only if there is a driveability complaint or if you have been directed here from another service information section.

Test Description

The numbers listed below refer to step numbers in the diagnostic procedure

1. 1 Determines if the scan tool is receiving power through the DLC.
2. 2 MIL should illuminate whenever the ignition is on and the engine is not running.
3. 3 Determines if the PCM is transmitting class 2 serial data to the DLC, and that the Class 2 data circuit is not open or shorted.
4. 4 Determines if a DTC is current or stored in history.

Diagnostic Procedure

Note. Check for applicable service bulletins before proceeding with this diagnostic procedure. Perform this diagnostic procedure only if there is a driveability complaint or if you have been directed to this diagnostic procedure from another section in the service information.

Note. Do not turn the ignition off when performing this diagnostic procedure. Do not clear the DTCs unless instructed by this diagnostic procedure.

1. Turn ignition on, engine off. Does the scan tool turn on? If so, go to next step. If not, diagnose scan tool concern. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
2. Is the MIL on? If so, go to next step. If not, diagnose MIL concern. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
3. Attempt to establish communication with the PCM. Does the scan tool communicate with the PCM? If so, go to next step. If not, diagnose scan tool concern. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.
4. Use the scan tool CAPTURE INFO function to save or capture (store information) any DTC information. Are there any DTCs present? If so, see «DIAGNOSTIC TROUBLE CODE DEFINITIONS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e__diagnostic-trouble-code-definitions) . If not, see «SYMPTOM DIAGNOSIS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e__symptom-diagnosis) .

Diagnostic Aids

Note. Do not clear the DTC unless directed by a diagnostic procedure. Clearing the DTC(s) will erase all freeze frame and failure records stored in PCM memory.

Note. Poor engine performance can sometimes be diagnosed as a transaxle driveability condition. To avoid mis-diagnosis of the automatic transaxle, always perform the powertrain on-board diagnostic system check.

Use a scan tool that is known to function correctly. If necessary, test the scan tool on another vehicle. Ensure the scan tool contains the most current file available. The scan tool will display a loss of communication error message under the following conditions

1. The PCM power is interrupted.
2. The ignition switch is turned off.
3. The battery voltage level is very low.
4. A poor connection at the Diagnostic Link Connector (DLC).

DIAGNOSTIC TROUBLE CODE DEFINITIONS

Note. Only transaxle-related DTCs are listed. For engine-related DTC definitions, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. These DTCs pertain to engine performance and must be repaired first, as engine performance and related component signals will affect transaxle operation and diagnosis.

DIAGNOSTIC TROUBLE CODE DEFINITIONS

CLEARING DIAGNOSTIC TROUBLE CODES

Using scan tool, clear DTCs following scan tool manufacturer's instructions. Do not clear DTCs unless instructed to do so.

SUMMARY

If no hard DTCs are present, and driveability symptoms or intermittent DTCs exist, attempt diagnosis by symptom, or by testing individual components related to system fault. See TROUBLE SHOOTING and/or COMPONENT TESTS . If no problem is found, verify proper electronic control system circuit operation.

Note. Always clear DTCs once repairs are complete. See CLEARING DIAGNOSTIC TROUBLE CODES . Road test vehicle and retrieve DTCs to determine if complaint or DTC is repaired.

DTC P0218: TRANSAXLE OVERHEATING

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Transaxle oil pump is constantly circulating fluid through torque converter. Hot fluid leaving converter flows through transaxle cooler lines to oil cooler located in radiator. Fluid is then routed back to transaxle.

Lube circuit No. 1 is routed through input shaft to lubricate transaxle components in front of transaxle. Lube circuit No. 2 is fed by line pressure at pressure regulator valve. This fluid is routed through oil feed pipes and into forward clutch support. Lube circuit No. 2 provides lubrication to rear of transaxle. DTC P0218 will set when PCM detects a high transmission fluid temperature for long period of time.

Conditions For Running DTC

DTC will run under the following condition

1. DTCs P0711, P0712 or P0713 are not present.

Conditions For Setting DTC

DTC will set under the following condition

1. Transaxle temperature is more than 260°F (130°C) for 10 minutes.

Action Taken By PCM

PCM performs the following if DTC is set

1. Does not illuminate the MIL.
2. Freezes shift adapts from being updated.
3. DTC P0218 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Inspect the transaxle cooling system for air flow restrictions, air flow blockage, debris and damaged cooler lines. Repair as necessary. Did you find and correct a condition? If so, go to step 7 . If not, go to next step.
4. Inspect the valve body for a stuck or leaking pressure regulator valve. Repair as necessary. Did you find and correct a condition? If so, go to step 7 . If not, go to next step.
5. Inspect the oil feed tubes for restrictions and leaking seals. Repair as necessary. Did you find and correct a condition? If so, go to step 7 . If not, go to next step.
6. Inspect the torque converter for stator damage. See appropriate OVERHAUL article. Did you find and correct the condition? If so, go to next step.
7. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Start and idle the engine until it reaches normal operating temperature. Select ENGINE RUN TIME and TRANS. FLUID TEMP. on the scan tool. Drive the vehicle for 15 minutes. Ensure that the transmission fluid temperature has stabilized and is less than 264°F (129°C). Select SPECIFIC DTC. Enter DTC P0218. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Question owner for possible vehicle overloading, exceeding trailer towing limit or towing in Overdrive.

DTC P0502: VSS CIRCUIT LOW INPUT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Note. The Vehicle Speed Sensor (VSS) may also be referred to as the Output Speed Sensor (OSS).

The OSS provides vehicle speed information to the PCM. The OSS is a permanent magnet generator mounted to the transaxle case. The OSS produces an AC voltage as the speed sensor rotor teeth pass through the sensor's magnetic field. The AC voltage level increases as the speed of the vehicle increases. The PCM converts the AC voltage into a digital signal. The PCM uses the vehicle speed signal to determine shift timing, TCC apply, TCC release, and gear ratio calculations.

When the PCM detects a low output speed and the vehicle has a large engine speed in a drive gear, then DTC P0502 sets.

DTC will run under the following conditions

1. No MAP sensor DTCs P0107 or P0108.
2. No TP sensor DTCs P0121, P0122, or P0123.
3. No ISS DTCs P0716 or P0717.
4. No TFP manual valve position switch DTC P1810.
5. The transaxle is in a drive range.
6. The throttle angle is greater than 12 percent.
7. The input speed is greater than 1500 RPM.
8. The engine torque is greater than 50 ft. lbs. (68 N.m).

DTC will set under the following condition

1. Output speed is less than 150 RPM for 3 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. Calculates output speed from input speed, engine speed and commanded gear.
5. DTC P0502 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install scan tool. Turn ignition on, engine off. Using scan tool, record freeze frame and failure records for reference. Clear DTC. Raise and support vehicle. Start engine and let it idle. Place gearshift lever in "D" position. With drive wheels rotating, does transaxle output speed increase when wheel speed increases? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
3. Turn ignition off. Disconnect PCM connectors. Connect DVOM set to AC scale between VSS high signal circuit and VSS low signal circuit terminals at appropriate PCM connector. Turn ignition on, engine off. Rotate right front drive wheel by hand, and observe DVOM. Is voltage more than .5 volt? If so, go to step 14 . If not, go to next step.
4. Turn ignition off. Set DVOM to ohms while still connected to VSS terminals at PCM connectors. Is resistance 1530-1870 ohms? If so, go to step 8 . If not, go to next step.
5. Is resistance more than 1870 ohms? If so, go to step 11 . If not, go to next step.
6. Leave DVOM test leads connected to appropriate PCM connector. Disconnect VSS connector at transaxle. Is resistance less than 1530 ohms? If so, go to next step. If not, go to step 13 .
7. Check for shorted together high and low signal circuits between PCM and VSS. Did you find and correct the condition? If so, go to step 15 .
8. Check for short to ground in VSS high signal circuit between PCM and VSS. Did you find and correct the condition? If so, go to step 15 . If not, go to next step.
9. Reconnect PCM connectors. Set DVOM to DC scale. Connect DVOM to VSS connector terminals. Turn ignition on, engine off. Does DVOM display system voltage? If so, go to next step. If not, go to step 12 .
10. Check for short to voltage in VSS high signal circuit between PCM and VSS. Did you find and correct the condition? If so, go to step 15 .
11. Check for open in VSS high and low signal circuits between PCM and VSS. Did you find and correct the condition? If so, go to step 15 . If not, go to step 13 .
12. Check for incorrect speed sensor, sensor damage, excessive air gap between sensor and rotor, rotor damage or incorrect rotor alignment. Inspect for transaxle case damage. Repair or replace components as necessary. After repairs, go to step 15 .
13. Replace VSS. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 15 .
14. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
15. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle and ensure output speed is greater than 250 RPM for 2 seconds. Select SPECIFIC DTC. Enter DTC P0502. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Condition may be intermittent. Check for loose speed sensor mounting or poor sensor connection. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change. Inspect for damaged speed sensor or transaxle rotor teeth.

DTC P0503: VSS CIRCUIT PERFORMANCE

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Note. The Vehicle Speed Sensor (VSS) may also be referred to as the Output Speed Sensor (OSS).

The Output Speed Sensor (OSS) provides vehicle speed information to the PCM. The OSS is a permanent magnet generator mounted to the transaxle case. The OSS produces an AC voltage as the transaxle speed sensor rotor teeth pass through the sensor's magnetic field. The AC voltage level increases as the speed of the vehicle increases. The PCM converts the AC voltage into a digital signal. The PCM uses the vehicle speed signal to determine shift timing, Torque Converter Clutch (TCC) apply, TCC release, and gear ratio calculations. When the PCM detects a loss of vehicle speed while the vehicle is in motion, then DTC P0503 sets.

DTC will run under the following conditions

1. No TFP manual valve position switch DTC P1810.
2. Time since gearshift lever change is more than 5 seconds.
3. An increase in output speed of 250 RPM or more has not occurred for more than 5 seconds.

DTC will set under the following conditions

1. Output speed drops more than 1200 RPM for 3 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. Calculates output speed from input speed, engine speed and commanded gear.
5. DTC P0503 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Connect scan tool to DLC. Turn ignition on, engine off. Using scan tool, record freeze frame and failure records for reference. Clear DTC. Raise and support vehicle. Start engine and let it idle. Place gearshift lever in "D" position. With drive wheels rotating, does transaxle output speed increase when wheel speed increases? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
3. Turn ignition off. Disconnect PCM connectors. Connect DVOM set to AC scale between VSS high signal circuit and VSS low signal circuit terminals at appropriate PCM connector. Turn ignition on, engine off. Rotate right front drive wheel by hand, and observe DVOM. Can a voltage greater than .5 volt be obtained? If so, go to step 14 . If not, go to next step.
4. Turn ignition off. Leave DVOM connected to VSS circuits at PCM connector and measure resistance of VSS circuit. Is circuit resistance 1530-1870 ohms? If so, go to step 8 . If not, go to next step.
5. Is circuit resistance greater than 1870 ohms? If so, go to step 11 . If not, go to next step.
6. Leave DVOM connected to appropriate PCM connector. Disconnect VSS connector at transaxle. Is circuit resistance less than 1530 ohms? If so, go to next step. If not, go to step 13 .
7. Check for shorted together VSS high and low signal circuits between PCM and VSS. Did you find and correct the condition? If so, go to step 15 .
8. Check for short to ground in VSS high signal circuit between PCM and VSS. Did you find and correct the condition? If so, go to step 15 . If not, go to next step.
9. Reconnect PCM connectors. Set DVOM to DC scale. Connect DVOM to VSS connector terminals. Turn ignition on, engine off. Does DVOM display system voltage? If so, go to next step. If not, go to step 12 .
10. Check for short to voltage in VSS high signal circuit between PCM and VSS. Did you find and correct the condition? If so, go to step 15 .
11. Check for open in VSS high and low signal circuits between PCM and VSS. Did you find and correct the condition? If so, go to step 15 . If not, go to step 13 .
12. Check for incorrect speed sensor, sensor damage, excessive air gap between sensor and rotor, rotor damage or incorrect rotor alignment. Inspect for transaxle case damage. Repair or replace components as necessary. After repairs, go to step 15 .
13. Replace VSS. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 15 .
14. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
15. After repair is complete, select DTC on scan tool. Select CLEAR INFO function. Select SPECIFIC DTC. Road test vehicle and ensure speed sensor is operating. If DTC P0503 is not present, repair is complete. If DTC P0503 is still present, go to step 1 .

Condition may be intermittent. Check for loose speed sensor mounting or poor sensor connection. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change. Inspect for damaged speed sensor or transaxle rotor teeth.

DTC P0705: TRANSAXLE RANGE SWITCH CIRCUIT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Transaxle Range (TR) switch is part of the Park/Neutral and back-up light switch. The PCM supplies ignition voltage to the TR switch on 4 signal circuits ("A", "B", "C" and "P"). Each gearshift lever position grounds one or more of the signal circuits in a unique pattern. To determine the gear range selected by the driver, the PCM compares the voltage combination on the signal circuits to a TR switch combination table stored in memory. When the PCM detects an invalid combination of TR signals, DTC P0705 sets.

DTC will run under the following conditions

1. System voltage is 8-18 volts.
2. Engine run time is more than 5 seconds.
3. Vehicle speed is more than 5 MPH.

DTC will set under the following condition

1. The combination of TR signals is invalid for 5 seconds.

PCM performs the following if DTC is set

1. Does not illuminate MIL.
2. Records operating conditions and stores this information as failure records.
3. DTC P0705 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install scan tool. Turn ignition on, engine off. Using scan tool, observe TR switch display while moving gearshift lever through all positions. Does each selected gearshift lever position match scan tool display? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
3. Inspect the TR switch for damage, loose or missing mounting hardware, and proper adjustment. Inspect the shift cable for damage or improper adjustment. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you find and correct the condition? If so, go to step 16 . If not, go to next step.
4. Using scan tool, observe the TR switch A/B/C/P display. Does the TR switch A/B/C/P display read HI for all ranges? If so, go to step 13 . If not, go to next step.
5. Turn ignition off. Disconnect the TR switch 4-way connector. Turn ignition on. Using scan tool, observe the TR switch A/B/C/P display. Does TR switch A/B/C/P display read HI for all ranges? If so, go to next step. If not, go to step 10 .
6. Measure voltage from TR switch 4-way connector terminals "A", "B", "C" and "D" to ground. Is voltage 10-12 volts at each terminal? If so, go to next step. If not, go to step 11 .
7. Connect a fused jumper wire from TR switch 4-way connector terminal "D" (signal "A" circuit) to ground, while monitoring scan TR switch A/B/C/P parameter. When signal "A" circuit (771) is grounded, do any other signal circuits read LOW? If so, go to step 12 . If not, go to next step.
8. Connect a fused jumper wire from TR switch 4-way connector terminal "B" (signal B circuit) to ground, while monitoring scan TR switch A/B/C/P parameter. When signal "B" circuit (772) is grounded, do any other signal circuits read LOW? If so, go to step 12 . If not, go to next step.
9. Connect a fused jumper wire from TR switch 4-way connector terminal "C" (signal C circuit) to ground, while monitoring scan TR switch A/B/C/P parameter. When signal "C" circuit (773) is grounded, do any other signal circuits read LOW? If so, go to step 12 . If not, go to step 14 .
10. Test the TR switch signal circuits that did not indicate HI for a short to ground. Did you find and correct the condition? If so, go to step 16 . If not, go to step 15 .
11. Test the TR switch signal circuits that did not indicate proper voltage for an open. Did you find and correct the condition? If so, go to step 16 . If not, go to step 15 .
12. Test the affected TR switch signal circuits for a shorted together condition. Did you find and correct the condition? If so, go to step 16 . If not, go to step 15 .
13. Test the TR switch ground circuit (451) for an open. Did you find and correct the condition? If so, go to step 16 . If not, go to next step.
14. Replace the TR switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 16 .
15. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
16. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive vehicle. Select SPECIFIC DTC. Enter DTC P0705. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change. Inspect transaxle wiring harness for ATF.

DTC P0711: TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT OUT OF RANGE

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Transmission Fluid Temperature (TFT) sensor is a negative coefficient thermistor. When the transmission fluid is cold, the sensor resistance is high. As the transmission fluid warms, the sensor resistance decreases. This diagnostic monitors the TFT sensor circuit. The circuit may be functional, but not in the normal operating range. This DTC indicates stuck, erratic, intermittent, or skewed values, indicating poor system performance. The TFT sensor range is -40-305°F (-40-151°C). When the PCM detects an intermittent voltage or no voltage change in the TFT sensor circuit, then DTC P0711 sets.

DTC will run under the following conditions

1. No VSS DTCs P0502 or P0503.
2. No ISS DTCs P0716 or P0717.
3. System voltage is 8-18 volts.
4. Engine run time is greater than 5 minutes.
5. Engine coolant temperature is greater than 158°F (70°C).
6. Engine coolant temperature has changed by greater than 90°F (50°C) since start-up.
7. Transmission fluid temperature at start-up is -40-70°F (-40-21°C).
8. Vehicle speed is more than 5 MPH for 6 minutes and 49 seconds.
9. TCC slip is more than 120 RPM for 6 minutes and 49 seconds.

DTC will set under one of the following conditions

1. Change in transmission fluid temperature is less than 2°F (1.5°C) since start-up for 80 seconds, or change in transmission fluid temperature is greater than 36°F (20°C) within 200 milliseconds, 15 times within 7 seconds.

PCM performs the following if DTC is set

1. Does not illuminate MIL.
2. Freezes shift adapts from being updated.
3. Will calculate default transmission fluid temperature based on engine coolant temperature, manifold air temperature and engine run time.
4. DTC P0711 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Using scan tool, monitor transmission fluid temperature. Drive the vehicle and observe the scan tool for either of the following fail conditions: The transmission fluid temperature does not change greater than 2.7°F (1.5°C) in 80 seconds since start-up. The transmission fluid temperature changes greater than 36°F (20°C) in 200 milliseconds, 15 times within 7 seconds (an unrealistic change). Did either of the fail conditions occur? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
4. Did the scan tool display a condition in which the transmission fluid temperature does not change by more than 2.7°F (1.5°C) in 80 seconds since start-up? If so, go to step 6 . If not, go to next step.
5. Turn ignition off. Disconnect transaxle 20-way connector. Install Jumper Harness (J-44152) on engine side of transaxle 20-way connector. Connect a test light between transaxle 20-way connector terminals "L" and "M". Turn ignition on, engine off. While observing scan tool display, wiggle wiring harness between transaxle 20-way connector and PCM connectors. Does transmission fluid temperature change by greater than 36°F (20°C)? If so, go to step 7 . If not, go to step 8 .
6. Turn ignition off. Disconnect transaxle 20-way connector. Turn ignition on, engine off. Did the scan tool display a condition in which the transmission fluid temperature does not change by greater than 2.7°F (1.5°C) in 80 seconds since start-up? If so, go to step 11 . If not, go to step 10 .
7. Check for intermittent open or short in TFT sensor signal and ground circuits between PCM and transaxle 20-way connector. Did you find and correct the condition? If so, go to step 12 . If not, go to step 11 .
8. Check for intermittent open or short in TFT sensor signal and ground circuits between transaxle 20-way connector and TFP manual valve position switch. If open or short is found in TFT sensor signal or ground circuits, go to next step. If TFT sensor signal and ground circuits are okay, go to step 10 .
9. Replace internal transaxle wire harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 12 .
10. Replace TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 12 .
11. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
12. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle and ensure the transmission fluid temperature changes by greater than 5°F (3°C) for 5 seconds since start-up. The transmission fluid temperature does not change by greater than 36°F (20°C) within 200 milliseconds, 15 times within 7 seconds. Select SPECIFIC DTC. Enter DTC P0711. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. Test TFT sensor at various temperature levels to evaluate possibility of a skewed (mis-scaled) sensor. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change. Inspect transaxle wiring harness for ATF.

DTC P0712: TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT LOW INPUT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Transmission Fluid Temperature (TFT) sensor is a thermistor. The TFT sensor is part of the Transmission Fluid Pressure (TFP) manual valve position switch. The PCM supplies a 5-volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the PCM senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the PCM senses lower voltage. The PCM uses the TFT sensor reading to control the Torque Converter Clutch (TCC), line pressure adjustments, and temperature compensated shifts. When the PCM detects a continuous short to ground in the TFT sensor circuit or the TFT sensor, then DTC P0712 sets.

DTC will run under the following conditions

1. Ignition is on.
2. System voltage is 8-18 volts.

DTC will set under the following condition

1. TFT sensor voltage is less than .33 volt for 10 seconds.

PCM performs the following if DTC is set

1. Does not illuminate MIL.
2. Freezes shift adapts from being updated.
3. Will calculate transaxle temperature based on engine coolant temperature, manifold air temperature and engine run time.
4. DTC P0712 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Select TFT SENSOR on the scan tool. Does the scan tool display a TFT sensor voltage greater than 0.33 volt? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
3. Turn ignition off. Disconnect transaxle 20-way connector. Turn ignition on, engine off. Does scan tool display a transmission fluid temperature voltage greater than 4.92 volts? If so, go to step 5 . If not, go to next step.
4. Check for short to ground in TFT sensor signal circuit between PCM and transaxle 20-way connector. Did you find and correct the condition? If so, go to step 11 . If not, go to step 10 .
5. Install Jumper Harness (J-44152) to transaxle side of transaxle 20-way connector. Measure resistance between jumper harness terminals "L" and "M". Is the resistance 3106-3923 ohms at 68°F (20°C) and 164-190 ohms at 212°F (100°C)? If so, go to next step. If not, go to step 7 .
6. Measure resistance between jumper harness terminal "L" and ground. Is resistance less than 1000 ohms? If so, go to step 9 . If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
7. Disconnect TFP manual valve position switch from transaxle wiring harness. Measure resistance between jumper harness terminal "L" and all other jumper harness terminals. Is the resistance between terminal "L" and any other terminal less than 1000 ohms? If so, go to step 9 . If not, go to next step.
8. Replace TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 11 .
9. Replace transaxle internal wire harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 11 .
10. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
11. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle. Turn ignition on, engine off. The TFT sensor signal voltage must be greater than 0.33 volt for 10 seconds. Select SPECIFIC DTC. Enter DTC P0712. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0713: TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT HIGH INPUT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Transmission Fluid Temperature (TFT) sensor is a thermistor. The TFT sensor is part of the Transmission Fluid Pressure (TFP) manual valve position switch. The PCM supplies a 5-volt reference signal to the sensor. When the transmission fluid is cold, the sensor resistance is high and the PCM senses a high signal voltage. As the transmission fluid warms, the sensor resistance lowers and the PCM senses lower voltage. The PCM uses the TFT sensor reading to control the Torque Converter Clutch (TCC), line pressure adjustments, and temperature compensated shifts. When the PCM detects a continuous open or short to voltage in the TFT sensor circuit or the TFT sensor, then DTC P0713 sets.

DTC will run under the following conditions

1. Ignition is on.
2. System voltage is 8-18 volts.

DTC will set under the following conditions

1. TFT sensor voltage is more than 4.9 volts for 6 minutes and 40 seconds.

PCM performs the following if DTC is set

1. Does not illuminate MIL.
2. Freezes shift adapts from being updated.
3. Will calculate transaxle temperature based on engine coolant temperature, manifold air temperature and engine run time.
4. DTC P0713 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Select TFT sensor on the scan tool. Does the scan tool display a TFT sensor voltage greater than 4.92 volts? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
3. Turn ignition off. Disconnect transaxle 20-way connector. Install Jumper Harness (J-44152) to transaxle side of transaxle 20-way connector. Measure resistance between jumper harness terminals "L" and "M". Is reading less than 100 k/ohms? If so, go to step 7 . If not, go to next step.
4. Test TFT sensor signal circuit and TFT sensor ground circuit for an open between transaxle 20-way connector and the TFT sensor. Did you find an open condition? If so, go to step 8 . If not, go to next step.
5. Measure resistance between jumper harness terminal "L" and all other jumper harness terminals. Is the resistance between terminal "L" and any other terminal less than the 1000 ohms? If so, go to step 10 . If not, go to next step.
6. Test TFT sensor signal circuit for a short to voltage between PCM and the 20-way connector. Did you find and correct the condition? If so, go to step 12 . If not, go to step 9 .
7. Test TFT sensor signal and ground circuits for an open between 20-way connector and PCM. Did you find and correct the condition? If so, go to step 12 . If not, go to step 11 .
8. Replace transaxle internal wire harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 12 .
9. Replace TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 12 .
10. Replace transaxle internal wire harness and TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Go to step 12 .
11. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
12. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle. Turn ignition on, engine off. The TFT sensor signal voltage must be less than 4.92 volts for 6 minutes and 40 seconds. Select SPECIFIC DTC. Enter DTC P0713. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0716: INPUT SPEED SENSOR CIRCUIT PERFORMANCE

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Input Speed Sensor (ISS) provides transaxle input speed to the PCM. The ISS is a permanent magnet generator. The sensor mounts into the transaxle case, and maintains a slight air gap between the sensor and the drive sprocket. The ISS produces an AC voltage as the drive sprocket rotor teeth pass through the sensor's magnetic field. The AC voltage level increases as the turbine shaft speed increases. The PCM converts the AC voltage into a digital signal. The PCM determines actual turbine speed using the digital signal. The PCM uses the input speed to calculate torque converter slip speed and gear ratios. When the PCM detects an unreasonably large change in the input speed, in a very short period of time, then DTC P0716 sets.

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122 or P0123.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTC P0717.
4. No 1-2 shift solenoid DTCs P0751 or P0753.
5. No 2-3 shift solenoid DTC P0758.
6. Engine is running.
7. Throttle angle is greater than 15 percent.
8. Vehicle speed is greater than 5 MPH.

DTC will set under the following condition

1. The input speed changes by greater than 1300 RPM in .8 second.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure reported.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P0716 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Start the engine. Select ISS on the scan tool. Is the input speed greater than 500 RPM? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the transaxle side of the transaxle 20-way connector. Measure the resistance between jumper harness terminals "S" and "V". Is the resistance 615-835 ohms? If so, go to step 7 . If not, go to next step.
4. Is the resistance greater than 835 ohms? If so, go to next step. If not, go to step 6 .
5. Test the ISS high and low signal circuits for a high resistance or an open between the transaxle 20-way connector and the ISS. Did you find a high resistance or open condition? If so, go to step 11 . If not, go to step 12 .
6. Test the VSS high and low signal circuits for being shorted together between the transaxle 20-way connector and the ISS. Did you find the condition? If so, go to step 11 . If not, go to step 12 .
7. Measure resistance between jumper harness terminal "S" and ground. Is the resistance less than 1000 ohms? If so, go to step 11 . If not, go to next step.
8. Measure resistance between jumper harness terminal "S" and all other jumper harness terminals, except terminal "V". Is the resistance between terminal "S" and any other terminal, except terminal "V", less than 1000 ohms? If so, go to step 11 . If not, go to next step.
9. Test the ISS high signal circuit for a high resistance, an open, a short to ground or a short to voltage between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 14 . If not, go to next step.
10. Test the ISS low signal circuit for a high resistance or an open between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 14 . If not, go to step 13 .
11. Replace the transaxle internal wire harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 14 .
12. Replace the ISS. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 14 .
13. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
14. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Place the transaxle in Park. Start the engine. The input speed must be greater than 50 RPM without a speed change greater than 300 RPM within 0.3 second. Select SPECIFIC DTC. Enter DTC P0716. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0717: INPUT SPEED SENSOR CIRCUIT NO SIGNAL

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Input Speed Sensor (ISS) provides transaxle input speed to the PCM. The ISS is a permanent magnet generator. The sensor mounts into the transaxle case, and maintains a slight air gap between the sensor and the drive sprocket. The ISS produces an AC voltage as the drive sprocket rotor teeth pass through the sensor's magnetic field. The AC voltage level increases as the turbine shaft speed increases. The PCM converts the AC voltage into a digital signal. The PCM determines actual turbine speed using the digital signal. The PCM uses the input speed to calculate torque converter slip speed and gear ratios. When the PCM detects a low input speed and the vehicle has a large vehicle speed, then DTC P0717 sets.

DTC will run under the following conditions

1. No VSS DTCs P0502 or P0503.
2. No TFP manual valve position switch DTC P1810.
3. Engine is running.
4. The TFP manual valve position switch indicates the vehicle is not in Park or Neutral.
5. Vehicle speed is greater than 5 MPH.

DTC will set under the following condition

1. Input speed is less than 100 RPM for 5 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with failure reported.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P0717 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Start the engine. Select ISS on the scan tool. Is the input speed greater than 500 RPM? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the transaxle side of the transaxle 20-way connector. Measure the resistance between jumper harness terminals "S" and "V". Is the resistance 615-835 ohms? If so, go to step 7 . If not, go to next step.
4. Is the resistance greater than 835 ohms? If so, go to next step. If not, go to step 6 .
5. Test the ISS high and low signal circuits for a high resistance or an open between the transaxle 20-way connector and the ISS. Did you find a high resistance or open condition? If so, go to step 11 . If not, go to step 12 .
6. Test the ISS high and low signal circuits for being shorted together between the transaxle 20-way connector and the ISS. Did you find the condition? If so, go to step 11 . If not, go to step 12 .
7. Measure resistance between jumper harness terminal "S" and ground. Is the resistance less than 1000 ohms? If so, go to step 11 . If not, go to next step.
8. Measure the resistance between jumper harness terminal "S" and all other jumper harness terminals, except terminal "V". Is the resistance between terminal "S" and any other terminal, except terminal "V", less than 1000 ohms? If so, go to step 11 . If not, go to next step.
9. Test the ISS high signal circuit for a high resistance, an open, a short to ground or a short to voltage between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 14 . If not, go to next step.
10. Test the ISS low signal circuit for a high resistance or an open between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 14 . If not, go to step 13 .
11. Replace transaxle internal wire harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 14 .
12. Replace input speed sensor. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 14 .
13. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
14. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Place the transaxle in Park. Start the engine. The input speed must be greater than 450 RPM for 2 seconds. Select SPECIFIC DTC. Enter DTC P0717. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0719: BRAKE SWITCH CIRCUIT LOW INPUT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The brake switch is used to indicate brake pedal status to PCM. Normally closed brake switch supplies battery voltage to PCM. When brake pedal is applied, brake switch opens, interrupting voltage to PCM. When brake pedal is released, voltage is constant to PCM. When PCM sees zero volts at brake switch input, PCM de-energizes TCC solenoid. DTC P0719 will set when PCM detects an open (stuck on) brake switch during acceleration.

DTC will run under the following conditions

1. Ignition is on.
2. System voltage is 8-18 volts.

DTC will set under the following conditions

1. Ignition is on.
2. PCM detects an open brake switch circuit (zero volts) for 15 minutes and following conditions occur 8 consecutive times: Vehicle speed is less than 5 MPH, then vehicle speed is 5-20 MPH for 3 seconds, then vehicle speed is greater than 20 MPH for 6 seconds.

PCM performs the following if DTC is set

1. Will not light MIL when fault is set.
2. Disregards the brake switch input for TCC scheduling. The PCM then uses throttle position and vehicle speed inputs to determine TCC application and release. Use of these inputs may result in a noticeable harsh apply or abrupt release of the TCC.
3. DTC P0719 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Select BRAKE SWITCH on the scan tool. Disconnect the brake switch connector. Install a fused jumper wire between brake switch connector terminals "A" and "B". Did the brake switch status change from OPEN to CLOSED? If so, go to step 5 . If not, go to next step.
3. Inspect appropriate fuse for brake switch power feed circuit. Is the fuse open? If so, go to next step. If not, go to step 6 .
4. Test brake switch power feed circuit for a short to ground. Repair as necessary. After repairs, go to step 9 .
5. Inspect brake switch for proper adjustment. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did brake switch require adjustment? If so, go to step 9 . If not, go to step 7 .
6. Test brake switch power feed and input circuits for open. Did you find and correct the condition? If so, go to step 9 . If not, go to step 8 .
7. Replace brake switch. See appropriate SHIFT INTERLOCK SYSTEMS article. After repairs, go to step 9 .
8. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
9. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Turn ignition on, engine off. Apply and release the brake pedal. The PCM must receive 12 volts (brake switch closed) on the circuit for 2 seconds. Select SPECIFIC DTC. Enter DTC P0719. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Ask customer about driving habits and/or unusual traffic conditions such as heavy stop and go driving. Check brake switch for proper adjustment. Inspect wiring for poor connections at PCM and at brake switch connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0724: BRAKE SWITCH CIRCUIT HIGH INPUT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The brake switch is used to indicate brake pedal status to PCM. Normally closed brake switch supplies battery voltage to PCM. When brake pedal is applied, brake switch opens, interrupting voltage to PCM. When brake pedal is released, voltage is constant to PCM. When PCM sees zero volts at brake switch input, PCM de-energizes TCC solenoid. DTC P0724 will set when PCM detects a closed (stuck off) brake switch during deceleration.

DTC will run under the following conditions

1. Ignition is on.
2. System voltage is 8-18 volts.

DTC will set under the following conditions

1. PCM detects a closed brake switch circuit (12 volts) during deceleration and following conditions occur 8 consecutive times: Vehicle speed is greater than 20 MPH for 6 seconds, then vehicle speed is 5-20 MPH for 3 seconds, then vehicle speed is less than 5 MPH.

PCM performs the following if DTC is set

1. Does not illuminate the MIL.
2. DTC P0724 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Select BRAKE SWITCH on the scan tool. Disconnect the brake switch connector. Does the brake switch status change from CLOSED to OPEN? If so, go to step 4 . If not, go to next step.
3. Check for short to voltage in brake switch input circuit. Did you find and correct the condition? If so, go to step 6 . If not, go to step 5 .
4. Replace brake switch. See appropriate SHIFT INTERLOCK SYSTEMS article. After repairs, go to step 6 .
5. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
6. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Turn ignition on, engine off. Apply the brake pedal for at least 3 seconds. Select SPECIFIC DTC. Enter DTC P0724. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Ask customer about driving habits and/or unusual traffic conditions such as heavy stop and go driving. Check brake switch for proper adjustment. Inspect wiring for poor connections at PCM and at brake switch connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0730: INCORRECT GEAR RATIO

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

PCM calculates gear ratio based on transaxle input and output speed sensor readings. PCM compares known transaxle gear ratio to calculated ratio for particular gear range selected. DTC P0730 will set when PCM detects an unknown transaxle gear ratio.

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122 or P0123.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTCs P0716 or P0717.
4. No TFP manual valve position switch DTC P1810.
5. Engine is running.
6. TFP manual valve position switch is not indicating Park or Neutral.
7. The time since the gear select lever change is greater than 6 seconds.
8. The transmission fluid temperature is greater than 68°F (20°C).
9. The throttle position is greater than 15 percent.
10. Vehicle speed is more than 5 MPH.

DTC will set when one of the following conditions occurs for 7 seconds

1. Gear ratio is more than 3.13:1.
2. Gear ratio is 2.23:1-2.87:1.
3. Gear ratio is 1.71:1-2.02:1.
4. Gear ratio is 1.07:1-1.54:1.
5. Gear ratio is .72:1-.91:1.
6. Gear ratio is less than .61:1.

PCM performs the following if DTC is set

1. Does not illuminate the MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P0730 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Visually inspect transaxle cooling system for fluid leaks. Repair as necessary. After repairs, go to step 8 . If no leaks are found, go to next step.
3. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
4. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Use the scan tool snapshot mode to record the transaxle gear ratios. Drive the vehicle in gear ranges "1", "2", "3", and "D" with the throttle angle greater than 15 percent, and the vehicle speed greater than 5 MPH. Record each gear. Did the gear ratio match the specified ranges? Reverse - 2.02:1-2.23:1 1st - 2.87:1-3.13:1 2nd - 1.54:1-1.71:1 3rd - 0.91:1-1.07:1 4th - 0.61:1-0.72:1 If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
5. Perform line pressure test. See «HYDRAULIC PRESSURE TESTS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e__hydraulic-pressure-tests) under PERFORMANCE TESTS. After test, go to next step.
6. Check for excessive clutch wear and repair as necessary. See appropriate OVERHAUL article. After repairs, go to next step.
7. Change transaxle fluid and filter. Inspect transaxle fluid for correct level. Add new fluid as necessary. Use scan tool to perform clear TAPS function.
8. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with the throttle angle greater than 15 percent to obtain any one of the following gear ratios for 7 seconds. Reverse - 2.02:1-2.23:1 1st - 2.87:1-3.13:1 2nd - 1.54:1-1.71:1 3rd - 0.91:1-1.07:1 4th - 0.61:1-0.72:1 Select SPECIFIC DTC. Enter DTC P0730. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Check for intermittent input speed sensor or vehicle speed sensor circuit problems, or for possible incorrect calibration.

DTC P0741: TORQUE CONVERTER CLUTCH CIRCUIT STUCK OFF

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Torque Converter Clutch (TCC) solenoid is a Pulse Width Modulated (PWM) solenoid. When vehicle operating conditions are appropriate to apply TCC, PCM begins TCC PWM duty cycle at about 42 percent. PCM then increases duty cycle up to 90 percent to achieve full TCC apply pressure.

When the TCC PWM solenoid valve is de-energized, the solenoid blocks filtered 2-3 drive fluid, and allows TCC signal fluid to exhaust. When energized, the solenoid modulates fluid into the TCC signal fluid circuit. When fully energized, modulation stops, and the solenoid blocks both 2-3 drive fluid and TCC signal fluid exhaust. When the PCM detects a high TCC slip speed when the TCC is commanded on, then DTC P0741 sets.

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122 or P0123.
2. No VSS DTCs P0502 or P0503.
3. No TCC stuck on DTC P0742.
4. No TFP manual valve position switch DTC P1810.
5. The time since the gearshift lever change is greater than 6 seconds.
6. Throttle angle is 8-75 percent.
7. Transmission fluid temperature is 70-266°F (21-130°C).
8. Transaxle Fluid Pressure (TFP) manual valve position switch indicates "2", "3" or "D" position.
9. PCM commands TCC on for greater than 3 seconds.

DTC will set under the following condition

1. The TCC slip speed is greater than 200 RPM for 6 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with first failure reported.
2. Inhibits TCC engagement.
3. Freezes shift adapts from being updated.
4. DTC P0741 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Drive the vehicle at 45 MPH. Using the scan tool, command the TCC PWM solenoid valve on. Monitor the TCC slip speed. Is the slip speed less than 50 RPM? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
4. Drive the vehicle at 45 MPH. Using the scan tool, command the TCC PWM solenoid valve on. Monitor the TCC DUTY CYCLE SHORT TO VOLTS parameter. Does the TCC DUTY CYCLE SHORT TO VOLTS parameter indicate a short to voltage when the TCC is commanded on? If so, go to step 8 of DTC P1860: TCC PWM SOLENOID CIRCUIT ELECTRICAL. If not, go to next step.
5. Inspect for the following conditions: TCC PMW solenoid "O" ring for leaks. TCC PMW solenoid valve filter restriction. Stuck TCC control valve. Stuck TCC regulated apply valve. TCC feed limit valve, binding or stuck due to sediment. Pressure regulator valve, binding or stuck due to sediment. TCC fluid circuits for leaks. Turbine shaft seals for leaks. Repair as necessary. After repairs, go to next step.
6. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position and the throttle angle greater than 8 percent. Obtain 45 MPH. With the TCC commanded on and engaged, the slip speed must be less than 50 RPM for 4 seconds. Select SPECIFIC DTC. Enter DTC P0741. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect transmission fluid level. Transaxle may be in hot mode. Inspect transaxle cooler lines to radiator. Lines may be pinched, plugged or twisted.

DTC P0742: TORQUE CONVERTER CLUTCH CIRCUIT STUCK ON

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Torque Converter Clutch (TCC) solenoid valve is a Pulse Width Modulation (PWM) solenoid. When vehicle operating conditions are appropriate for TCC application, the PCM begins the TCC duty cycle at about 42 percent. The PCM then increases the duty cycle up to 90 percent, to achieve full TCC apply pressure.

When the TCC PWM solenoid valve is de-energized, the solenoid blocks filtered 2-3 drive fluid, and allows TCC signal fluid to exhaust. When energized, the solenoid modulates fluid into the TCC signal fluid circuit. When fully energized, modulation stops, and the solenoid blocks both 2-3 drive fluid and TCC signal fluid exhaust.

The TCC release switch is part of the Transmission Fluid Pressure (TFP) manual valve position switch. The TFP manual valve position switch is attached to the control valve body.

The TCC release switch is a normally closed switch. The switch signals the PCM that the TCC is released. Torque converter release fluid pressure acts on the switch contact, opening the signal circuit. When the voltage on the circuit is high, the PCM recognizes that the TCC is no longer engaged. When the PCM detects that the TCC release switch is closed when the TCC is commanded off, then DTC P0742 sets.

DTC will run under the following conditions

1. No TP DTCs P0121, P0122 or P0123.
2. No TCC release switch DTC P1887.
3. Engine is running.
4. Throttle angle is greater than 12 percent.
5. TCC is commanded off.

DTC will set under the following condition

1. The TCC release switch is closed, release fluid pressure not present, for 4 seconds, 4 times during the same trip.

PCM performs the following if DTC is set

1. Illuminates MIL.
2. TCC will be commanded on.
3. Freezes shift adapts from being updated.
4. DTC P0742 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Select TCC RELEASE PRESSURE on the scan tool. Start the engine. Does the scan tool indicate TCC release pressure is present? If so, go to step 7 . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Does the scan tool indicate TCC release pressure is present? If so, go to step 5 . If not, go to next step.
4. Test the TCC release switch signal circuit for a short to ground between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 11 . If not, go to step 10 .
5. Test the TCC release switch signal circuit for a short to ground between the transaxle 20-way connector and the TFP manual valve position switch. Did you find the condition? If so, go to step 9 . If not, go to next step.
6. Remove the TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Inspect the TCC release switch for a damaged or leaking seal, sediment or debris in the switch, damaged switch contacts or stuck switch contacts. Did you find a condition? If so, go to step 8 . If not, go to next step.
7. Inspect for the following conditions: The TCC PWM solenoid valve for the fluid exhaust being restricted. The TCC regulated apply valve for being stuck in the TCC apply position. The TCC control valve for being stuck in the TCC apply position. The TCC feed limit valve for being stuck. This causes the TCC feed limit pressure, and the TCC release pressure to be low or nonexistent. The pressure regulator valve for being stuck. The TCC fluid circuits for leaks. Abnormally high or low line pressure. Repair any of the above conditions as necessary. Did you find and correct a condition? If so, go to step 11 . If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
8. Replace the TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 11 .
9. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 11 .
10. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
11. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Start the engine. TCC release pressure must be present for 3 seconds. Select SPECIFIC DTC. Enter DTC P0742. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Rapid fluctuation in line pressure could set DTC P0742. Check for pressure regulator malfunction and low or high line pressure. Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. Customer may notice an engine stalling condition. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0748: PRESSURE CONTROL SOLENOID ELECTRICAL

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The PCM uses the Pressure Control (PC) solenoid valve to regulate the transaxle line pressure. The PC solenoid valve consists of an electrical connector, a coil, an armature, a regulating spring, and a poppet valve. The PC solenoid valve is attached to the control valve body. The PCM compares TP sensor voltage, fluid temperature, gear states, and other inputs to determine the line pressure appropriate for a given load. The PCM regulates the pressure by applying a varying amperage to the PC solenoid valve. The applied amperage varies from 0.1 amp for maximum line pressure to 1.1 amps for minimum line pressure. The PCM then monitors the amperage at the return line. When the PCM detects a continuous open, short to ground or short to voltage in the PC solenoid valve circuit, then DTC P0748 sets.

DTC will run under the following condition

1. System voltage is 8-18 volts.

DTC will set under the following condition

1. PC solenoid duty cycle is zero percent or greater than 95 percent.

PCM performs the following if DTC is set

1. Does not illuminate the MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure (zero amps).
4. DTC P0748 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Start the engine. Using the scan tool, apply 0.1 amp through 1.0 amps. Observe the scan tool display. Does the PC SOL. ACTUAL CURRENT amp reading differ from the PC SOL. REF. CURRENT amp reading by no more than 0.16 amp? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the transaxle side of the transaxle 20-way connector. Measure the resistance between jumper harness terminals "C" and "D". Is the resistance 3-7 ohms? If so, go to step 7 . If not, go to next step.
4. Is the resistance between jumper harness terminals "C" and "D" greater than 7 ohms? If so, go to next step. If not, go to step 6 .
5. Test the PC solenoid high and low circuits for an open between the transaxle 20-way connector and the PC solenoid. Did you find a condition? If so, go to step 18 . If not, go to step 19 .
6. Test the PC solenoid high and low circuits for being shorted together between the transaxle 20-way connector and the PC solenoid. Did you find a condition? If so, go to step 18 . If not, go to step 19 .
7. Measure the resistance from jumper harness terminal "C" to ground. Is the resistance less than 1000 ohms? If so, go to next step. If not, go to step 9 .
8. Test the PC solenoid high and low circuits for a short to ground between the transaxle 20-way connector and the PC solenoid. Did you find a condition? If so, go to step 18 . If not, go to step 19 .
9. Measure the resistance between jumper harness terminal "C" and all other jumper harness terminals, except terminal "D". Is the resistance between terminal "C" and any other terminal, except terminal "D", less than 10 ohms? If so, go to step 18 . If not, go to next step.
10. Disconnect the jumper harness from the transaxle side of the transaxle 20-way connector. Install the jumper harness on the engine side of the transaxle 20-way connector. Disconnect PCM connector C2. Additional DTCs may set. Measure the resistance from jumper harness terminal "D" to ground. Is the resistance less than 10 ohms? If so, go to next step. If not, go to step 12 .
11. Test the PC solenoid low circuit for a short to ground between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 21 .
12. Measure the resistance of PC solenoid low circuit between jumper harness terminal "D" and appropriate terminal of PCM connector C2. Is the resistance less than 10 ohms? If so, go to step 14 . If not, go to next step.
13. Test the PC solenoid low circuit for an open between the PCM connector C2 and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 21 .
14. Measure the resistance from jumper harness terminal "C" to ground. Is the resistance less than 10 ohms? If so, go to next step. If not, go to step 16 .
15. Test the PC solenoid highcircuit for a short to ground between the PCM connector C2 and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 21 .
16. Measure the resistance of the PC solenoid high circuit between jumper harness terminal "C" and appropriate terminal of PCM connector C2. Is the resistance less than 10 ohms? If so, go to step 20 . If not, go to next step.
17. Test the PC solenoid high circuit for an open between the PCM connector C2 and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 21 .
18. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 21 .
19. Replace the PC solenoid valve. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 21 .
20. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
21. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Turn ignition on, engine off. Select SPECIFIC DTC. Enter DTC P0748. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. Extended engine cranking with a weak battery could set DTC P0748. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0751: 1-2 SHIFT SOLENOID STUCK OFF

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The 1-2 shift solenoid valve is a normally open exhaust valve that, in conjunction with the 2-3 shift solenoid valve, allows four different shifting combinations. See SHIFT SOLENOID OPERATION table under DESCRIPTION & OPERATION. The 1-2 shift solenoid valve is attached to the control valve body, within the transaxle. The PCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0751 sets if the 1-2 shift solenoid or 1-2 shift valve is stuck off. When the PCM detects a 2-2-3-3 shift pattern, then DTC P0751 sets.

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122, or P0123.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTCs P0716 or P0717.
4. No shift solenoid electrical DTCs P0753 or P0758.
5. No TFP manual valve position switch DTC P1810.
6. The system voltage is 8-18 volts.
7. Engine is running.
8. TFP manual valve position switch is not in Park, Reverse or Neutral.
9. Transmission fluid temperature is greater than 70°F (21°C).
10. Throttle angle is greater than 8 percent.
11. Vehicle speed is greater than 5 MPH.

The following occurs twice during the same trip

1. PCM commands 1st gear and gear ratio is between 1.54-1.71 (2nd gear) for 4 seconds.
2. PCM commands 4th gear and gear ratio is between .91-1.07 (3rd gear) for 4 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. Inhibits TCC engagement.
5. DTC P0751 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record current gear and gear ratio. Drive the vehicle to obtain 1-2, 2-3 and 3-4 shifts with a throttle angle greater than 8 percent. Are the current gear and gear ratio 1st/2nd = 1.54:1-1.71:1 and 3rd/4th = 0.91:1-1.07:1? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
4. Inspect the 1-2 shift circuit for the following conditions: 1-2 shift solenoid valve mechanically stuck off. Damaged 1-2 shift solenoid valve "O" ring. 1-2 shift valve stuck in the released position. Repair the circuit as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
5. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position. Allow the transaxle to shift through all gears. Monitor the current gear and gear ratios. The actual gear ratios must match the commanded gears for 0.75 second, for all gears. Select SPECIFIC DTC. Enter DTC P0751. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Check for stuck throttle position sensor. If DTC P0751 cannot be reset after clearing DTC, check for possible fluid contamination or plugged or restricted oil circuits.

DTC P0752: 1-2 SHIFT SOLENOID VALVE STUCK ON

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The 1-2 shift solenoid valve is a normally open exhaust valve that, in conjunction with 2-3 shift solenoid valve, allows four different shifting combinations. See SHIFT SOLENOID OPERATION table under DESCRIPTION & OPERATION. The 1-2 shift solenoid valve is attached to control valve body, within transaxle. PCM monitors actual gear ratio, and compares actual gear ratio with commanded gear ratio. DTC P0752 sets when PCM detects a 1-1-4-4 shift pattern.

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122, or P0123.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTCs P0716 or P0717.
4. No shift solenoid electrical DTCs P0753 or P0758.
5. No TFP manual valve position switch DTC P1810.
6. The system voltage is 8-18 volts.
7. Engine is running.
8. TFP manual valve position switch is not indicating Park, Reverse or Neutral.
9. Transmission fluid temperature is more than 70°F (21°C).
10. Throttle angle is more than 8 percent.
11. Vehicle speed is more than 5 MPH.

The following occurs twice during the same trip

1. PCM commands 2nd gear and gear ratio is 2.87:1-3.13:1 (1st gear) for 4 seconds.
2. PCM commands 3rd gear and gear ratio is 0.61:1-0.72:1 (4th gear) for 4 seconds.

1. Illuminates MIL after 2 consecutive trips with failure reported.
2. Commands maximum line pressure.
3. Inhibits TCC engagement.
4. Inhibits 3-2 downshifts above 35 MPH.
5. Freezes shift adapts from being updated.
6. DTC P0752 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record current gear and gear ratio. Drive the vehicle with gearshift lever in "D" position to obtain 1-2, 2-3 and 3-4 shifts with a throttle angle greater than 8 percent. Are current gear and gear ratio 1st/2nd = 2.87:1-3.13:1 and 3rd/4th = 0:61:1-0.72:1? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
4. Inspect the 1-2 shift circuit for 1-2 shift solenoid valve mechanically stuck on and 1-2 shift valve stuck in the applied position. Repair the circuit as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
5. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position. Allow the transaxle to shift through all the gears. Monitor the current gear and gear ratios. The actual gear ratios must match the commanded gears for 0.75 second, for all gears. Select SPECIFIC DTC. Enter DTC P0752. Has the test run and passed? If so, system is okay. If not, go to step 1 .

If DTC P0752 cannot be reset after clearing DTC, check for possible fluid contamination or plugged or restricted oil circuits.

DTC P0753: 1-2 SHIFT SOLENOID ELECTRICAL

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The 1-2 shift solenoid is used to control fluid flow acting on 1-2 shift valve. Solenoid is a normally open valve that is used in conjunction with 2-3 shift solenoid to allow 4 different shifting combinations. See SHIFT SOLENOID OPERATION table under DESCRIPTION & OPERATION. Solenoid is attached to control valve body. Ignition voltage is supplied directly to solenoid through fused circuit. PCM commands solenoid on or off by providing a ground path. DTC P0753 will set when PCM detects a continuous open, short to ground or short to voltage in 1-2 shift solenoid circuit.

DTC will run under the following conditions

1. Ignition is on.
2. System voltage is 8-18 volts.

DTC will set under the following conditions

1. PCM commands solenoid on and voltage remains high (battery voltage) for 4.3 seconds.
2. PCM commands solenoid off and voltage remains low (zero volts) for 4.3 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. Inhibits TCC engagement.
5. DTC P0753 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Is DTC P0758 or P1860 also set? If so, go to next step. If not, go to step 8 .
3. Remove ERLS fuse 10-amp ("J" body) from instrument panel fuse block or AUTO TRANS fuse ("N" body) from underhood fuse block and inspect fuse. Replace fuse if necessary. If fuse was open, go to next step. If fuse is okay, go to step 6 .
4. Test the 1-2 shift solenoid power feed circuit for a short to ground between the fuse block and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 . If not, go to next step.
5. Test the 1-2 shift solenoid valve power feed circuit for short to ground between transaxle 20-way connector and 1-2 shift solenoid. Did you find the condition? If so, go to step 23 .
6. Test the 1-2 shift solenoid valve power feed circuit for an open between the fuse block and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 . If not, go to next step.
7. Test the 1-2 shift solenoid valve power feed circuit for an open between the transaxle 20-way connector and the 1-2 shift solenoid valve. Did you find the condition? If so, go to step 23 .
8. Use the scan tool to command the 1-2 shift solenoid valve on and off 3 times. Listen at the transaxle side cover. Does the solenoid click when commanded on and off? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
9. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Install the Jumper Harness (J-44152) on the engine side of the transaxle 20-way connector. Connect a test light between jumper harness terminals "E" and "A". Turn ignition on, engine off. Command the 1-2 shift solenoid valve on and off three times. Is the test light on when you command the solenoid on, and off when you command the solenoid off? If so, go to step 17 . If not, go to next step.
10. Is the test light always on? If so, go to next step. If not, go to step 13 .
11. Turn ignition off. Disconnect PCM connector C2 on 2.2L and 2.4L models, or connector C1 on 3.1L and 3.4L models. Additional DTCs may set. Turn ignition on, engine off. Is the test light on? If so, go to next step. If not, go to step 25 .
12. Test the 1-2 shift solenoid valve control circuit for a short to ground between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 .
13. Is the test light always off? If so, go to next step.
14. Test the 1-2 shift solenoid control circuit for an open between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 . If not, go to next step.
15. Connect a test light from jumper harness terminal "A" to ground. Is the test light on? If so, go to next step. If not, go to step 25 .
16. Test the 1-2 shift solenoid valve control circuit for a short to voltage between the PCM and the transaxle 20-way connector. Repair as necessary. After repairs, go to step 26 .
17. Turn ignition off. Disconnect the jumper harness from the engine side of the transaxle 20-way connector. Install the jumper harness on the transaxle side of the transaxle 20-way connector. Measure the resistance between jumper harness terminals "E" and "A". Is the resistance 19-31 ohms? If so, go to step 20 . If not, go to next step.
18. Is the resistance greater than 31 ohms? If so, go to next step. If not, go to step 20 .
19. Test the 1-2 shift solenoid valve control circuit for an open between the transaxle 20-way connector and the 1-2 shift solenoid valve. Test the 1-2 shift solenoid valve power feed circuit for an open between the transaxle 20-way connector and the 1-2 shift solenoid valve. Did you find a condition? If so, go to step 23 . If not, go to step 24 .
20. Measure the resistance from jumper harness terminal "A" to ground. Is the resistance less than 1000 ohms? If so, go to next step. If not, go to step 22 .
21. Test the 1-2 shift solenoid valve control circuit for a short to ground between the transaxle 20-way connector and the 1-2 shift solenoid valve. Did you find the condition? If so, go to step 23 .
22. Measure the resistance between jumper harness terminal "A" and all other jumper harness terminals, except terminals "B", "E" and "T". Is the resistance between terminal "A" and any other terminal, except terminal "B", "E" and "T", less than 1000 ohms? If so, go to next step. If not, go to step 24 .
23. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 26 .
24. Replace the 1-2 shift solenoid valve. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. After repairs, go to step 26 .
25. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
26. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position. Allow the transaxle to obtain a 1-2, 2-3, and 3-4 upshift. Select SPECIFIC DTC. Enter DTC P0753. Has the test run and passed? If so, system is okay. If not, go to step 1 .

An open in circuit wire between transaxle 20-way connector and fuse can cause multiple DTCs to set. Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P0756: 2-3 SHIFT SOLENOID STUCK ON

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The 2-3 shift solenoid valve is a normally open exhaust valve that, in conjunction with the 1-2 shift solenoid valve, allows four different shifting combinations. See SHIFT SOLENOID OPERATION table under DESCRIPTION & OPERATION. The 2-3 shift solenoid valve is attached to the control valve body, within the transaxle. The PCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0756 sets under two conditions: A stuck on 2-3 shift solenoid valve or a stuck on 2-3 shift valve.

DTC P0756 will set when PCM detects a 4-3-3-4 shift pattern.

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122 or P0123.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTCs P0716 or P0717.
4. No shift solenoid electrical DTCs P0753 or P0758.
5. No engine torque DTC P1644.
6. No TFP manual valve position switch DTC P1810.
7. The system voltage is 8-18 volts.
8. Engine is running.
9. The TFP manual valve position switch is not indicating Park, Reverse, or Neutral.
10. Transmission fluid temperature is greater than 70°F (21°C).
11. Vehicle speed is greater than 5 MPH.
12. Throttle angle is greater than 8 percent.
13. The engine torque is greater than 20 ft. lbs. (27 N.m).

All conditions exist when any one of the following conditions occur

1. The PCM commands 1st gear and the gear ratio is 0.61:1-0.72:1 (4th gear) for 4 seconds.
2. The PCM commands 2nd gear and the gear ratio is 0.91:1-1.07:1 (3rd gear) for 4 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. Commands immediate shift to 2nd gear.
5. Inhibits TCC engagement.
6. DTC P0756 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record current gear and gear ratio. Drive the vehicle with gearshift lever in "D" position to obtain 1-2, 2-3 and 3-4 shifts with a throttle angle greater than 8 percent. Are current gear and gear ratio 1st/4th = 0.61:1-0.72:1 and 2nd/3rd = 0.91:1-1.07:1? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
4. Inspect the 2-3 shift circuit for 2-3 shift solenoid valve mechanically stuck on or 2-3 shift valve stuck in the applied position. Repair the circuit as necessary. After repairs, go to next step.
5. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position. Allow the transaxle to shift through all the gears. Monitor the current gear and gear ratios. The actual gear ratios must match the commanded gears for 0.75 second, for all gears. Select SPECIFIC DTC. Enter DTC P0756. Has the test run and passed? If so, system is okay. If not, go to step 1 .

If DTC P0756 cannot be reset after clearing DTC, check for possible fluid contamination or plugged or restricted oil circuit.

DTC P0757: 2-3 SHIFT SOLENOID STUCK OFF

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The 2-3 shift solenoid valve is a normally open exhaust valve that, in conjunction with the 1-2 shift solenoid valve, allows four different shifting combinations. See SHIFT SOLENOID OPERATION table under DESCRIPTION & OPERATION. The 2-3 shift solenoid valve is attached to the control valve body, within the transaxle. The PCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0757 sets under two conditions: A stuck off 2-3 shift solenoid valve or a stuck off 2-3 shift valve.

DTC P0757 will set when PCM detects a 1-2-2-1 shift pattern.

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122 or P0123.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTCs P0716 or P0717.
4. No shift solenoid electrical DTCs P0753 or P0758.
5. No engine torque DTC P1644.
6. No TFP manual valve position switch DTC P1810.
7. The system voltage is 8-18 volts.
8. Engine is running.
9. The TFP manual valve position switch is not indicating Park, Reverse, or Neutral.
10. Transmission fluid temperature is greater than 70°F (21°C).
11. The input speed is greater than 150 RPM.
12. Vehicle speed is greater than 5 MPH.
13. Throttle angle is greater than 8 percent.

DTC will set when one of the following conditions occur

1. The PCM commands 3rd gear and the gear ratio is 1.54:1-1.71:1 (2nd gear) for 3 seconds.
2. The PCM commands 4th gear and the gear ratio is 2.87:1-3.13:1 (1st gear) for 2 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. Commands immediate shift to 2nd gear.
5. Inhibits TCC engagement.
6. DTC P0757 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record current gear and gear ratio. Drive the vehicle with gearshift lever in "D" position to obtain 1-2, 2-3 and 3-4 shifts with a throttle angle greater than 8 percent. Are current gear and gear ratio 1st/4th = 2.87:1-3.13:1 and 2nd/3rd = 1.54:1-1.71:1? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
4. Inspect the 2-3 shift circuit for 2-3 shift solenoid valve mechanically stuck off, damaged 2-3 shift solenoid valve "O" ring or 2-3 shift valve stuck in the released position. Repair the circuit as necessary. After repairs, go to next step.
5. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position. Allow the transaxle to shift through all the gears. Monitor the current gear and gear ratios. The actual gear ratios must match the commanded gears for 0.75 second, for all gears. Select SPECIFIC DTC. Enter DTC P0757. Has the test run and passed? If so, system is okay. If not, go to step 1 .

If DTC P0757 cannot be reset after clearing DTC, check for possible fluid contamination or plugged or restricted oil circuit.

DTC P0758: 2-3 SHIFT SOLENOID ELECTRICAL

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The 2-3 shift solenoid valve is a normally open exhaust valve that, in conjunction with the 1-2 shift solenoid valve, allows four different shifting combinations. See SHIFT SOLENOID OPERATION under DESCRIPTION & OPERATION. The 2-3 shift solenoid valve is attached to the control valve body, within the transaxle.

The solenoid receives ignition voltage through the fused power feed circuit. The PCM commands the solenoid on or off by providing a ground path.

When the PCM detects a continuous open, short to ground, or short to voltage in the 2-3 shift solenoid valve circuit, then DTC P0758 sets.

DTC will run under the following conditions

1. Ignition is on.
2. System voltage is 8-18 volts.

DTC will set under the following conditions

1. PCM commands solenoid on and voltage remains high for 4.3 seconds.
2. PCM commands solenoid off and voltage remains low for 4.3 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. Commands immediate shift to 2nd gear.
5. Inhibits TCC engagement.
6. DTC P0758 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Is DTC P0753 or P1860 also set? If so, go to next step. If not, go to step 8 .
3. Remove the power feed fuse for the 2-3 shift solenoid. Inspect the fuse for an open. Did you find the condition? If so, go to next step. If not, go to step 6 .
4. Test the 2-3 shift solenoid valve power feed circuit for a short to ground between the fuse block and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 . If not, go to next step.
5. Test the 2-3 shift solenoid valve power feed circuit for a short to ground between the transaxle 20-way connector and the 2-3 shift solenoid valve. Did you find the condition? If so, go to step 23 .
6. Test the 2-3 shift solenoid valve power feed circuit for an open between the fuse block and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 . If not, go to next step.
7. Test the 2-3 shift solenoid valve power feed circuit for an open between the transaxle 20-way connector and the 2-3 shift solenoid valve. Did you find the condition? If so, go to step 23 .
8. Use the scan tool to command the 2-3 shift solenoid valve on and off 3 times. Listen at the transaxle side cover. Does the solenoid click when commanded on and off? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
9. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle 20-way connector. Connect a test light between jumper harness terminal "E" and "B". Turn ignition on, engine off. Command the 2-3 shift solenoid valve on and off three times. Is the test light on when you command the solenoid on, and off when you command the solenoid off? If so, go to step 17 . If not, go to next step.
10. Is the test light always on? If so, go to next step. If not, go to step 13 .
11. Turn ignition off. Disconnect PCM connector C2 on 2.2L and 2.4L models, or connector C1 on 3.1L and 3.4L models. Additional DTCs may set. Turn ignition on, engine off. Is the test light on? If so, go to next step. If not, go to step 25 .
12. Test the 2-3 shift solenoid valve control circuit for a short to ground between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 .
13. Is the test light always off? If so, go to next step.
14. Test the 2-3 shift solenoid valve control circuit for an open between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 . If not, go to next step.
15. Connect a test light from jumper harness terminal "B" to ground. Is the test light on? If so, go to next step. If not, go to step 25 .
16. Test the 2-3 shift solenoid valve control circuit for a short to voltage between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 26 .
17. Turn ignition off. Disconnect the jumper harness from the engine side of the transaxle 20-way connector. Install the jumper harness on the transaxle side of the transaxle 20-way connector. Measure the resistance between jumper harness terminals "E" and "B". Is the resistance 19-31 ohms? If so, go to step 20 . If not, go to next step.
18. Is the resistance greater than 31 ohms? If so, go to next step. If not, go to step 20 .
19. Test the 2-3 shift solenoid valve control circuit for an open between the transaxle 20-way connector and the 2-3 shift solenoid valve. Test the 2-3 shift solenoid power feed circuit for an open between the transaxle 20-way connector and the 2-3 shift solenoid valve. Did you find a condition? If so, go to step 23 . If not, go to step 24 .
20. Measure the resistance from jumper harness terminal "B" to ground. Is the resistance less than 1000 ohms? If so, go to next step. If not, go to step 22 .
21. Test the 2-3 shift solenoid control circuit for a short to ground between the transaxle 20-way connector and the 2-3 shift solenoid valve. Did you find the condition? If so, go to step 23 .
22. Measure the resistance between jumper harness terminal "B" and all other jumper harness terminals, except terminal "A", "E" and "T". Is the resistance between terminal "B" and any other terminal, except terminal "A", "E" and "T", less than 1000 ohms? If so, go to next step. If not, go to step 24 .
23. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 26 .
24. Replace the 2-3 shift solenoid valve. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 26 .
25. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
26. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position. Allow the transaxle to obtain a 1-2, 2-3 and 3-4 upshift. Select SPECIFIC DTC. Enter DTC P0758. Has the test run and passed? If so, system is okay. If not, go to step 1 .

An open in power feed circuit between shift solenoid and fuse can cause multiple DTCs to set. Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P1810: PRESSURE SWITCH ASSEMBLY MALFUNCTION

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Note. Pressure Switch Assembly (PSA) is also referred to as Transmission Fluid Pressure (TFP) manual valve position switch.

The Transmission Fluid Pressure (TFP) manual valve position switch consists of six pressure switches. Five of the switches are normally open, and determine gear range selection. The sixth switch is normally closed, and detects TCC release fluid pressure. The TFP manual valve position switch also contains the Transmission Fluid Temperature (TFT) sensor. These components are combined into one unit, attached to the control valve body.

The PCM provides battery voltage on the three range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the PCM detects the selected gear range. When you disconnect the transaxle 20-way connector and the ignition is on, the ground potential for three range signals from the PCM will be removed, and an invalid gear range will be indicated. See TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC table under DESCRIPTION & OPERATION. DTC P1810 will set when PCM detects an invalid gear status, a drive range indicated at start-up or an incorrect gear ratio.

1. Engine is running.
2. System voltage is 8-18 volts.

Condition No. 1 For Setting DTC

Note. The DTC will set under one of the following three conditions.

Gear range is invalid for 60 seconds. See TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC table under DESCRIPTION & OPERATION.

Condition No. 2 For Setting DTC

1. No VSS DTCs P0502 or P0503.
2. The engine speed is in transition from zero RPM to greater than 600 RPM.
3. The vehicle speed is less than 2 MPH.
4. "D2", "D4" or Reverse is indicated after start-up for 2 seconds.

Condition No. 3 For Setting DTC

1. No TP sensor DTCs P0121, P0122, or P0123.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTCs P0716 or P0717.
4. No shift solenoid DTCs P0751, P0752, P0753, P0756, P0757 or P0758.
5. The TP sensor is 10-25 percent.
6. The vehicle speed is 5 MPH or greater.
7. The engine torque is 10 ft. lbs. (14 N.m) or greater.
8. All of the above conditions are met and one of the following occurs for 5 seconds: The TFP manual valve position switch indicates Park/Neutral when the gear ratio is less than 0.72:1 (4th gear). The TFP manual valve position switch indicates Reverse when the gear ratio is greater than 2.23:1, or less than 2.02:1. The TFP manual valve position switch indicates a Drive range when the gear ratio indicates Reverse.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Increases line pressure.
4. Assumes "D" shift pattern.
5. Inhibits TCC engagement.
6. DTC P1810 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Start the engine and idle at the normal operating temperature. Using scan tool, monitor TFP switch. Apply the brake pedal. Select each transaxle range. Does each selected transaxle range match the scan tool TFP switch display? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
4. Inspect the transaxle linkage from the gearshift lever to the manual valve for proper adjustment. Adjust the linkage as necessary. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did the linkage require adjustment? If so, go to step 17 . If not, go to next step.
5. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Does the scan tool TFP switch A/B/C parameter indicate HI for all range states? If so, go to next step. If not, go to step 10 .
6. Turn ignition off. Install Jumper Harness (J-44152) on the engine side of the transaxle 20-way connector. Turn ignition on, engine off. Measure the voltage from jumper harness terminal "N" to ground. Measure the voltage from jumper harness terminal "R" to ground. Measure the voltage from jumper harness terminal "P" to ground. Does the voltage measure ignition voltage at all three terminals? If so, go to next step. If not, go to step 11 .
7. Connect a fused jumper wire from jumper harness terminal "N" (range "A" circuit) to ground while monitoring the scan tool TFP switch A/B/C parameter. When the range "A" circuit (1224) is grounded, do any other range circuits indicate LOW? If so, go to step 12 . If not, go to next step.
8. Connect a fused jumper wire from jumper harness terminal "R" (range "B" circuit) to ground while monitoring the scan tool TFP switch A/B/C parameter. When the range "B" circuit (1225) is grounded, do any other range circuits indicate LOW? If so, go to step 12 . If not, go to next step.
9. Connect a fused jumper wire from jumper harness terminal "P" (range "C" circuit) to ground while monitoring the scan tool TFP switch A/B/C parameter. When the range "C" circuit (1226) is grounded, do any other range circuits indicate LOW? If so, go to step 12 . If not, go to step 13 .
10. Test the TFP manual valve position switch range circuits that did not indicate HI for a short to a ground between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 17 . If not, go to step 16 .
11. Test the TFP manual valve position switch range circuits that did not indicate ignition voltage for an open between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 17 . If not, go to step 16 .
12. Test the affected TFP manual valve position switch range circuits for a shorted together condition between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 17 . If not, go to step 16 .
13. Test the affected TFP manual valve position switch range circuits for an open or shorted condition between the transaxle 20-way connector and the TFP manual valve position switch. Did you find the condition? If so, go to next step. If not, go to step 15 .
14. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 17 .
15. Replace the TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 17 .
16. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
17. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Start the vehicle and idle in Park for 10 seconds. Drive the vehicle with gearshift lever in "D" position and a throttle angle greater than 10 percent. Allow the transaxle to shift through all gears. Select SPECIFIC DTC. Enter DTC P1810. Has the test run and passed? If so, system is okay. If not, go to step 1 .

A pressure regulator malfunction could set DTC P1810. Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P1811: MAXIMUM ADAPT & LONG SHIFT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The PCM modifies the line pressure through the Pressure Control (PC) solenoid valve to control shift execution time and shift consistency. The PCM monitors various inputs, and modifies the shift execution and timing by applying a calculated duty cycle to the PC solenoid valve. The PCM alters the shifting based on driving habits, transaxle load, and internal transaxle condition. When the PCM detects long shifts that cannot be shortened by shift adapts during the same ignition cycle, then DTC P1811 sets.

DTC will run under the following conditions

1. Shift is adaptable.
2. Shift adapt is at limit.

DTC will set under the following conditions

1. Shift time is greater than .65 second twice during ignition cycle.

PCM performs the following if DTC is set

1. Does not illuminate the MIL.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P1811 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Use the scan tool snapshot mode to record the shift times. Drive the vehicle with gearshift lever in "D" position to obtain 1-2, 2-3, and 3-4 shift times. Record the shift times. Did all the shift times exceed 0.65 second? If so, go to next step. If not, go to step 6 .
4. Perform line pressure check. See «HYDRAULIC PRESSURE TESTS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e__hydraulic-pressure-tests) under PERFORMANCE TESTS. Go to next step.
5. Inspect the transaxle for the following conditions: Low fluid level caused by external leaks. Clogged fluid filter. Out-of-position fluid filter. Internal fluid passage leaks. Casting porosity or damage. Damaged gasket or spacer plate. Out-of-position gasket or spacer plate. Contaminated PC solenoid valve. Damaged PC solenoid valve. Stuck PC solenoid valve. Stuck pressure regulator valve train. Leaking pressure regulator valve train. Stuck torque signal valve train. Leaking torque signal valve train. Leaking oil pump. Damaged oil pump. Inadequate oil pump suction. Oil pump cavitation. Repair any of the above conditions as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to step 12 .
6. Did the 1-2 shift time exceed 0.65 second? If so, go to step 9 . If not, go to next step.
7. Did the 2-3 shift time exceed 0.65 second? If so, go to step 10 . If not, go to next step.
8. Did the 3-4 shift time exceed 0.65 second? If so, go to step 11 .
9. Inspect the 1-2 shift circuit for the following conditions: Leaking 1-2 accumulator piston seals. Rolled 1-2 accumulator piston seals. Cut 1-2 accumulator piston seals. Leaking 2nd clutch piston seals. Rolled 2nd clutch piston seals. Cut 2nd clutch piston seals. Burned 2nd clutch plates. Damaged 2nd clutch plates. Broken 2nd clutch springs. Out-of-position 2nd clutch springs. Damaged 2nd clutch piston. Leaking driven sprocket support seals. Damaged driven sprocket support seals. Internal fluid passage leaks. Casting porosity or damage. Damaged gasket or spacer plate. Out-of-position gasket or spacer plate. Slipping forward clutch. Cracked or damaged driven sprocket support. Damaged sprag clutch, not holding. 2nd roller clutch damaged, not holding. Repair the 1-2 shift circuit as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to step 12 .
10. Inspect the 2-3 shift circuit for the following conditions: Leaking 2-3 accumulator piston seals. Rolled 2-3 accumulator piston seals. Cut 2-3 accumulator piston seals. Leaking direct clutch piston seals. Rolled direct clutch piston seals. Cut direct clutch piston seals. Burned direct clutch plates. Damaged direct clutch plates. Broken direct clutch springs. Out-of-position direct clutch springs. Damaged direct clutch pistons. Leaking driven sprocket support seals. Damaged driven sprocket support seals. Damaged driven sprocket support. Damaged, or not holding, sprag clutch. Internal fluid passage leaks. Casting porosity or damage. Damaged gasket or spacer plate. Out-of-position gasket or spacer plate. Repair the 2-3 shift circuit as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to step 12 .
11. Inspect the 3-4 shift circuit for the following conditions: Leaking 3-4 accumulator piston seals. Rolled 3-4 accumulator piston seals. Cut 3-4 accumulator piston seals. Leaking intermediate-4th servo piston seals. Rolled intermediate-4th servo piston seals. Cut intermediate-4th servo piston seals. Burned intermediate-4th band. Out-of-position intermediate-4th band. Damaged intermediate-4th band. Slipping intermediate-4th band. Internal fluid passage leaks. Casting porosity or damage. Damaged gasket or spacer plate. Out-of-position gasket or spacer plate. Slipping direct clutch. Damaged intermediate-4th servo pin. Seized intermediate-4th servo pin. Damaged intermediate-4th servo piston. Cracked intermediate-4th servo cover. Leaking intermediate-4th servo cover. Repair the 3-4 shift circuit as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
12. Change the transmission fluid and filter. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Use the scan tool to perform the CLEAR TAPS function. Did you complete the procedures? If so, go to next step.
13. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position to obtain 1-2, 2-3, and 3-4 shifts. Shift times must be less than 0.65 second. Select SPECIFIC DTC. Enter DTC P1811. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Question owner about vehicle overloading, exceeding trailer towing limit or towing in overdrive. If after several unsuccessful attempts to gain accurate shift times and an adapt can be made, reset adapts and operate vehicle to assure proper shifting.

DTC P1815: TFP MANUAL VALVE POSITION SWITCH - START IN WRONG RANGE

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Note. Pressure Switch Assembly (PSA) is also referred to as Transmission Fluid Pressure (TFP) manual valve position switch.

The Transmission Fluid Pressure (TFP) manual valve position switch consists of six pressure switches. Five of the switches are normally open, and determine gear range selection. The sixth switch is normally closed, and detects Torque Converter Clutch (TCC) release fluid pressure. The TFP manual valve position switch also contains the Transmission Fluid Temperature (TFT) sensor. These components are combined into one unit, attached to the control valve body.

The PCM provides battery voltage on the three range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the PCM detects the selected gear range. When you disconnect the transaxle 20-way in-line connector and the ignition is on, the ground potential for three range signals from the PCM will be removed, and an invalid gear range will be indicated. See TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC table under DESCRIPTION & OPERATION. When the PCM detects a gear range other than Park/Neutral indicated at start-up, DTC P1815 sets.

DTC will run under the following condition

1. The system voltage is 8-18 volts.

DTC will set under the following conditions

1. No VSS DTCs P0502 or P0503.
2. No ISS DTCs P0716 or P0717.
3. The engine speed is in transition from zero RPM to greater than 600 RPM.
4. The vehicle speed is less than 2 MPH.
5. "D2", "D4" or Reverse is indicated after start-up for 2 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P1815 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Start the engine and idle at the normal operating temperature. Using scan tool, monitor TFP switch. Apply the brake pedal. Select each transaxle range. Does each selected transaxle range match the scan tool TFP switch display? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
4. Inspect the shift linkage from the gearshift lever to the manual valve for proper adjustment. Adjust the linkage as necessary. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did the shift linkage require adjustment? If so, go to step 17 . If not, go to next step.
5. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Does the scan tool TFP switch A/B/C parameter indicate HI for all range states? If so, go to next step. If not, go to step 10 .
6. Turn ignition off. Install the Jumper Harness (J-44152) on the engine side of the transaxle 20-way connector. Turn ignition on, engine off. Measure the voltage from jumper harness terminal "N" to ground. Measure the voltage from jumper harness terminal "R" to ground. Measure the voltage from jumper harness terminal "P" to ground. Does the voltage measure ignition voltage at all three terminals? If so, go to next step. If not, go to step 11 .
7. Connect a fused jumper wire from jumper harness terminal "N" (range "A" circuit) to ground while monitoring the scan tool TFP switch A/B/C parameter. When the range "A" circuit (1224) is grounded, do any other range circuits indicate LOW? If so, go to step 12 . If not, go to next step.
8. Connect a fused jumper wire from jumper harness terminal "R" (range "B" circuit) to ground while monitoring the scan tool TFP switch A/B/C parameter. When the range "B" circuit (1225) is grounded, do any other range circuits indicate LOW? If so, go to step 12 . If not, go to next step.
9. Connect a fused jumper wire from jumper harness terminal "P" (range "C" circuit) to ground while monitoring the scan tool TFP switch A/B/C parameter. When the range "C" circuit (1226) is grounded, do any other range circuits indicate LOW? If so, go to step 12 . If not, go to step 13 .
10. Test the TFP manual valve position switch range circuits that did not indicate HI for a short to a ground between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 17 . If not, go to step 16 .
11. Test the TFP manual valve position switch range circuits that did not indicate ignition voltage for an open between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 17 . If not, go to step 16 .
12. Test the affected TFP manual valve position switch range circuits for a shorted together condition between the PCM and the transaxle 20-way connector. Did you find and correct a condition? If so, go to step 17 . If not, go to step 16 .
13. Test the affected TFP manual valve position switch range circuits for an open or shorted condition between the transaxle 20-way connector and the TFP manual valve position switch. Did you find the condition? If so, go to next step. If not, go to step 15 .
14. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 17 .
15. Replace the TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 17 .
16. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
17. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Road test vehicle. Select SPECIFIC DTC. Enter DTC P1815, P1816, P1817 or P1818 depending on DTC being tested. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P1816: TFP MANUAL VALVE POSITION SWITCH - PARK/NEUTRAL WITH DRIVE RATIO

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Note. Pressure Switch Assembly (PSA) is also referred to as Transmission Fluid Pressure (TFP) manual valve position switch.

The Transmission Fluid Pressure (TFP) manual valve position switch consists of six pressure switches. Five of the switches are normally open, and determine gear range selection. The sixth switch is normally closed, and detects Torque Converter Clutch (TCC) release fluid pressure. The TFP manual valve position switch also contains the Transmission Fluid Temperature (TFT) sensor. These components are combined into one unit, attached to the control valve body.

The PCM provides battery voltage on the three range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the PCM detects the selected gear range. When you disconnect the transaxle 20-way in-line connector and the ignition is on, the ground potential for three range signals from the PCM will be removed, and an invalid gear range will be indicated. See TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC table under DESCRIPTION & OPERATION. When the PCM detects Park/Neutral with a drive gear ratio, DTC P1816 sets.

DTC will run under the following conditions

1. No PSA DTCs P1810, P1815, P1817 or P1818.
2. The vehicle speed is 5 MPH or more.
3. The throttle angle is greater than 10 percent.
4. The engine torque is greater than 10 ft. lbs. (13 N.m).

DTC will set under the following conditions

1. The PCM detects Park/Neutral with a drive ratio less than 3.11 for 5 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P1816 will be stored in PCM history.

Diagnosis Procedure

For diagnosis procedure, see DIAGNOSTIC PROCEDURE under DTC P1815: TFP MANUAL VALVE POSITION SWITCH - START IN WRONG RANGE.

DTC P1817: TFP MANUAL VALVE POSITION SWITCH - REVERSE WITH DRIVE RATIO

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Note. Pressure Switch Assembly (PSA) is also referred to as Transmission Fluid Pressure (TFP) manual valve position switch.

The Transmission Fluid Pressure (TFP) manual valve position switch consists of six pressure switches. Five of the switches are normally open, and determine gear range selection. The sixth switch is normally closed, and detects Torque Converter Clutch (TCC) release fluid pressure. The TFP manual valve position switch also contains the Transmission Fluid Temperature (TFT) sensor. These components are combined into one unit, attached to the control valve body.

The PCM provides battery voltage on the three range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the PCM detects the selected gear range. When you disconnect the transaxle 20-way in-line connector and the ignition is on, the ground potential for three range signals from the PCM will be removed, and an invalid gear range will be indicated. See TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC table under DESCRIPTION & OPERATION. When the PCM detects Reverse with a Drive gear ratio, DTC P1817 sets.

DTC will run under the following conditions

1. No PSA DTCs P1810, P1815, P1816 or P1818.
2. The vehicle speed is 5 MPH or more.
3. The throttle angle is greater than 10 percent.
4. The engine torque is greater than 10 ft. lbs. (13 N.m).

DTC will set under the following conditions

1. The PCM detects Reverse with a Drive gear ratio.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P1817 will be stored in PCM history.

For diagnosis procedure, see DIAGNOSTIC PROCEDURE under DTC P1815: TFP MANUAL VALVE POSITION SWITCH - START IN WRONG RANGE.

DTC P1818: TFP MANUAL VALVE POSITION SWITCH - DRIVE WITHOUT DRIVE RATIO

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Note. Pressure Switch Assembly (PSA) is also referred to as Transmission Fluid Pressure (TFP) manual valve position switch.

The Transmission Fluid Pressure (TFP) manual valve position switch consists of six pressure switches. Five of the switches are normally open, and determine gear range selection. The sixth switch is normally closed, and detects Torque Converter Clutch (TCC) release fluid pressure. The TFP manual valve position switch also contains the Transmission Fluid Temperature (TFT) sensor. These components are combined into one unit, attached to the control valve body.

The PCM provides battery voltage on the three range signal circuits. By grounding one or more of the switches with fluid pressure from the manual shift valve, the PCM detects the selected gear range. When you disconnect the transaxle 20-way in-line connector and the ignition is on, the ground potential for three range signals from the PCM will be removed, and an invalid gear range will be indicated. See TFP MANUAL VALVE POSITION SWITCH ASSEMBLY LOGIC table under DESCRIPTION & OPERATION. When the PCM detects a Drive gear with a Reverse ratio, DTC P1818 sets.

DTC will run under the following conditions

1. No PSA DTCs P1810, P1815, P1816 or P1817.
2. The vehicle speed is 5 MPH or more.
3. The throttle angle is greater than 10 percent.
4. The engine torque is greater than 10 ft. lbs. (13 N.m).

DTC will set under the following conditions

1. The PCM detects a Drive range with a Reverse ratio.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Commands maximum line pressure.
4. DTC P1818 will be stored in PCM history.

For diagnosis procedure, see DIAGNOSTIC PROCEDURE under DTC P1815: TFP MANUAL VALVE POSITION SWITCH - START IN WRONG RANGE.

DTC P1860: TCC PWM SOLENOID CIRCUIT ELECTRICAL

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

Torque Converter Clutch (TCC) Pulse Width Modulated (PWM) solenoid is a normally closed solenoid used to control apply and release of converter clutch. PCM operates TCC PWM solenoid with a negative duty cycle. When vehicle operating conditions are appropriate to apply TCC, PCM immediately increases duty cycle to about 42 percent. PCM then increases duty cycle to about 90 percent to achieve full TCC apply pressure. When solenoid is commanded on, PCM will detect high voltage. When solenoid is commanded off, PCM will detect low voltage. DTC P1860 will set when PCM detects a continuous open, short to ground or short to voltage in TCC PWM solenoid circuit.

DTC will run under the following conditions

1. System voltage is 8-18 volts.
2. Engine has been running for more than 5 seconds, and is not in fuel shut-off mode.
3. TCC duty cycle is less than 10 percent or more than 90 percent.

DTC will set under the following conditions

1. PCM detects an open, short to ground or short to voltage in TCC PWM solenoid circuit for 5 seconds.

PCM performs the following if DTC is set

1. Illuminates MIL.
2. Inhibits TCC engagement.
3. Freezes shift adapts from being updated.
4. DTC P1860 will be stored in PCM history.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC failure records. Clear the DTC. Is DTC P0753 or P0758 also set? If so, go to next step. If not, go to step 8 .
3. Remove appropriate fuse for TCC PWM solenoid valve power feed circuit. Inspect the fuse for an open. Did you find the condition? If so, go to next step. If not, go to step 6 .
4. Test the TCC PWM solenoid valve power feed circuit for a short to ground between the fuse block and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 25 . If not, go to next step.
5. Test the TCC PWM solenoid valve power feed circuit for a short to ground between the transaxle 20-way connector and the TCC PWM solenoid valve. Did you find the condition? If so, go to step 22 .
6. Test the TCC PWM solenoid valve power feed circuit for an open between the fuse block and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 25 . If not, go to next step.
7. Test the TCC PWM solenoid valve power feed circuit for an open between the transaxle 20-way connector and the TCC PWM solenoid valve. Did you find the condition? If so, go to step 22 .
8. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle 20-way connector. Connect a test light between jumper harness terminals "E" and "T". Turn ignition on, engine off. Is the test light on? If so, go to next step. If not, go to step 11 .
9. Turn ignition off. Disconnect the PCM connectors. Additional DTCs may set. Turn ignition on, engine off. Is the test light on? If so, go to next step. If not, go to step 24 .
10. Test the TCC PWM solenoid valve control circuit for a short to ground between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 25 .
11. Using the scan tool, cycle the TCC PWM solenoid valve on and off three times. Does the test light cycle on and off as commanded? If so, go to step 16 . If not, go to next step.
12. Is the test light always off? If so, go to next step.
13. Test the TCC PWM solenoid valve control circuit for an open between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 25 . If not, go to next step.
14. Connect a test light from jumper harness terminal "T" to ground. Is the test light on? If so, go to next step. If not, go to step 24 .
15. Test the TCC PWM solenoid valve control circuit for a short to voltage between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 25 .
16. Turn ignition off. Disconnect the jumper harness from the engine side of the transaxle 20-way connector. Install the jumper harness on the transaxle side of the transaxle 20-way connector. Measure the resistance between jumper harness terminals "E" and "T". Is the resistance 10-15 ohms? If so, go to step 19 . If not, go to next step.
17. Is the resistance greater than 15 ohms? If so, go to next step. If not, go to step 19 .
18. Test the TCC PWM solenoid valve control circuit for an open between the transaxle 20-way connector and the TCC PWM solenoid valve. Test the TCC PWM solenoid valve power feed circuit for an open between the transaxle 20-way connector and the TCC PWM solenoid valve. Did you find a condition? If so, go to step 22 . If not, go to step 23 .
19. Measure the resistance from jumper harness terminal "T" to ground. Is the resistance less than 1000 ohms? If so, go to next step. If not, go to step 21 .
20. Test the TCC PWM solenoid valve control circuit for a short to ground between the transaxle 20-way connector and the TCC PWM solenoid valve. Did you find a condition? If so, go to step 22 .
21. Measure the resistance between jumper harness terminal "T" and all other jumper harness terminals, except terminals "A", "B" and "E". Is the resistance between terminal "T" and any other terminal, except terminals "A", "B" and "E", less than 1000 ohms? If so, go to next step. If not, go to step 23 .
22. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 25 .
23. Replace the TCC PWM solenoid valve. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 25 .
24. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
25. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position. Increase vehicle speed until the TCC is applied. Ensure that the TCC duty cycle is 10-90 percent for more than 5 seconds. Select SPECIFIC DTC. Enter DTC P1860. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Ensure transaxle fluid level is correct. Inspect PCM, transaxle and TCC PWM solenoid connectors for bent, broken or backed out terminals. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. Check for moisture or corrosion. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

DTC P1887: TCC RELEASE SWITCH CIRCUIT

Note. For circuit identification, see CONNECTOR IDENTIFICATION and/or WIRING DIAGRAMS .

The Torque Converter Clutch (TCC) release switch is part of the Transmission Fluid Pressure (TFP) manual valve position switch. The TFP manual valve position switch is attached to the control valve body. The TCC release switch is normally closed.

The switch signals the PCM that the TCC is released. This is accomplished by torque converter release fluid pressure acting on the switch contact, thus opening the switch. When the voltage is high on the circuit, the PCM recognizes that the TCC is no longer engaged. When the PCM determines that the TCC release switch is open, indicating that the TCC is not applied, and the TCC slip speed indicates that the TCC is applied, then DTC P1887 sets.

DTC will run under the following conditions

1. No ISS DTCs P0716 or P0717.
2. No TCC DTCs P0741 or P0742.
3. Engine is running.
4. Transaxle Fluid Pressure (TFP) manual valve position switch is in D4.
5. Engine torque is more than 30 ft. lbs. (41 N.m).
6. TCC is commanded on.
7. TCC slip speed is between -20 RPM and 40 RPM.

DTC will set under the following conditions

1. The TCC release switch is open, release fluid pressure present, for 6 seconds, twice during the same trip.

PCM performs the following if DTC is set

1. Illuminates MIL after 2 consecutive trips with a failure signal.
2. Freezes shift adapts from being updated.
3. Inhibits TCC engagement.
4. DTC P1887 will be stored in PCM history after conditions are met during 2 consecutive trips.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Record the DTC freeze frame and failure records. Clear the DTC. Using scan tool, monitor TCC release pressure. Does the scan tool indicate TCC release pressure is present? If so, go to next step. If not, go to step 6 .
3. Turn ignition off. Disconnect the transaxle 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle 20-way connector. Connect a fused jumper wire from jumper harness terminal "U" to ground. Turn ignition on, engine off. Does the scan tool indicate TCC release pressure is present? If so, go to next step. If not, go to step 5 .
4. Test the TCC release switch signal circuit for an open between the PCM and the transaxle 20-way connector. Did you find and correct the condition? If so, go to step 11 . If not, go to step 10 .
5. Test the TCC release switch signal circuit for an open between the transaxle 20-way connector and the TFP manual valve position switch. Did you find the condition? If so, go to step 8 . If not, go to step 9 .
6. Use the scan tool snapshot mode to record TCC slip speed and TCC release pressure. Operate the vehicle under the following conditions: Drive the vehicle with the gearshift lever in "D" position. Increase the vehicle speed until the TCC is applied. Ensure that slip speed is less than 40 RPM. With the TCC applied and slip speed less than 40 RPM, does the scan tool indicate TCC release pressure is present? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) .
7. Inspect for the following conditions: Leaking torque converter "O" ring seal. Cut torque converter "O" ring seal. Debris or flash blocking the channel plate at the TCC release exhaust passage. Leaking oil pump bearing and seal assembly seal. Cut oil pump bearing and seal assembly seal. Oil pump bearing and seal assembly installed backwards. Misaligned valve body to spacer plate gasket. Misaligned spacer plate to channel plate gasket. Channel plate turbine shaft sleeve installed backwards, or with no press fit. Damaged valve body spacer plate, release exhaust orifice, valve body to spacer plate gasket, or spacer plate to channel plate gasket. Cut turbine shaft to sprocket seal. Missing turbine shaft to sprocket seal. Repair any of the above conditions as necessary. Did you complete the repair? If so, go to step 11 .
8. Replace the transaxle internal wiring harness. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the repair? If so, go to step 11 .
9. Replace the TFP manual valve position switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the repair? If so, go to step 11 .
10. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
11. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle with gearshift lever in "D" position to obtain 45 MPH. With the TCC commanded on and engaged, TCC release pressure must not be present for 3 seconds. Select SPECIFIC DTC. Enter DTC P1887. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections at PCM and transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change.

The Transmission Range (TR) switch is part of the park/neutral position and back-up lamp switch assembly, and is mounted on the transmission manual shaft. The TR switch is a multi-signal switch. The PCM supplies ignition voltage to the TR switch on four signal circuits: "A", "B", "C", and "P". Each gear selector lever position grounds one or more of the signal circuits in a unique pattern. In order to determine the gear range selected by the driver, the PCM compares the voltage combination on the signal circuits to a TR switch combination table stored in memory. See TRANSAXLE RANGE SWITCH LOGIC table under DESCRIPTION & OPERATION.

1. Install a scan tool. Turn ignition on, engine off. Select TR SW. on the scan tool. With the scan tool, observe the TR SW. display while selecting each transaxle range. Does each selected transaxle range match the scan tool TR SW. display? If so, see «DIAGNOSTIC AIDS»(/chevrolet/malibu/v-2000-2003/remont/automatic-trans/#automatic-transaxle-diagnosis-4t40-e-4t45-e) . If not, go to next step.
2. Inspect the PNP switch assembly for damaged, loose or missing mounting hardware and proper adjustment. Inspect the shift cable for damaged or stretched cable and proper adjustment. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you find and correct a condition? If so, go to step 15 .
3. Using scan tool, observe the TR switch A/B/C/P display. Does the scan tool TR switch A/B/C/P parameter indicate HI for all range signal states? If so, go to step 12 . If not, go to next step.
4. Turn ignition off. Disconnect the TR switch 4-way connector. Turn ignition on, engine off. Does the scan tool TR switch A/B/C/P parameter indicate HI for all range signal states? If so, go to next step. If not, go to step 9 .
5. Measure the voltage from TR switch 4-way connector terminal "A" to ground. Measure the voltage from TR switch 4-way connector terminal "B" to ground. Measure the voltage from TR switch 4-way connector terminal "C" to ground. Measure the voltage from TR switch 4-way connector terminal "D" to ground. Does the voltage measure 10-12 volts at all four terminals? If so, go to next step. If not, go to step 10 .
6. Connect a fused jumper wire from TR switch 4-way connector terminal "D" (signal "A" circuit) to ground while monitoring the scan tool TR switch A/B/C/P parameter. When the signal "A" circuit (771) is grounded, do any other signal circuits indicate LOW? If so, go to step 11 . If not, go to next step.
7. Connect a fused jumper wire from the TR switch 4-way connector terminal "B" (signal "B" circuit) to ground while monitoring the scan tool TR switch A/B/C/P parameter. When the signal "B" circuit (772) is grounded, do any other signal circuits indicate LOW? If so, go to step 11 . If not, go to next step.
8. Connect a fused jumper wire from the TR switch 4-way connector terminal "C" (signal "C" circuit) to ground while monitoring the scan tool TR switch A/B/C/P parameter. When the signal "C" circuit (773) is grounded, do any other signal circuits indicate LOW? If so, go to step 11 . If not, go to step 13 .
9. Test the TR switch signal circuit or circuits that did not indicate HI for a short to ground. Did you find and correct the condition? If so, go to step 15 . If not, go to step 14 .
10. Test the TR switch signal circuit or circuits that did not indicate proper voltage for an open. Did you find and correct the condition? If so, go to step 15 . If not, go to step 14 .
11. Test the affected TR switch signal circuits for a shorted together condition. Did you find and correct the condition? If so, go to step 15 . If not, go to step 14 .
12. Test the TR switch ground circuit for an open. Did you find and correct the condition? If so, go to step 15 . If not, go to next step.
13. Replace the TR switch. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did you complete the replacement? If so, go to step 15 .
14. Replace PCM. After replacement, program PCM. See appropriate REMOVAL, OVERHAUL & INSTALLATION article in ENGINE PERFORMANCE. After repairs, go to next step.
15. Turn ignition on, engine off. Using the scan tool, observe the TR switch display while selecting each transaxle range. Does each selected transaxle range match the scan tool TR switch display? If so, system is okay. If not, go to step 2 .

Inspect wiring for poor connections at PCM and at transaxle 20-way connector. Check for bent, backed out, deformed or damaged terminals. Check for weak terminal tension. Check for chafed wire that could short to bare metal or other wiring. Inspect for broken wire inside insulation. If diagnosing for intermittent short or open condition, manipulate harness while observing scan tool for value change. Inspect transaxle wiring harness for transmission fluid.

SHIFT SOLENOID LEAK TEST

Note. This procedure tests ON/OFF type solenoid valves.

Note. Visually inspect the physical condition of the solenoid before testing. Inspect the "O" rings before and after the test to be sure that they are not cut or damaged.

1. Remove the solenoid from the control valve body.
2. Install the 1-2 or the 2-3 shift solenoid valve into bore No. 2 of the Solenoid Testing Kit (J-44246), and install the factory retainer clip to retain the solenoid. (Scheme 95)
3. Connect the solenoid testing harness supplied with the solenoid tester to the solenoid. (Scheme 96)
4. Apply compressed air to the solenoid tester.
5. Air should flow through the solenoid. If air does not flow through the solenoid, replace the solenoid.
6. Connect the solenoid testing harness to the positive and negative battery terminals.
7. Observe if the solenoid is operating electrically. An audible clicking noise can be heard when connecting or disconnecting power.
8. Observe the air flow through the solenoid. The flow will completely or nearly completely stop. Replace the solenoid if there continues to be an obvious air leak when the solenoid is energized.
9. Install the solenoid into the control valve body.

Scheme 95

Scheme 96

COMPONENT RESISTANCE

Connect DVOM between specified terminals at component or at transaxle 20-way connector to transaxle. (Scheme 101) Measure individual component resistance at specified temperature. See COMPONENT RESISTANCE SPECIFICATIONS table. If resistance is not as specified, replace appropriate component. (Scheme 51)

COMPONENT RESISTANCE SPECIFICATIONS

Scheme 97

Scheme 98

Scheme 99

Scheme 100

Scheme 101

Scheme 102

Transaxle Electronic Control System Wiring Diagram (2001 Alero & Grand Am - 2.4L). Scheme 103

Transaxle Electronic Control System Wiring Diagram (2001 Alero & Grand Am - 3.4L). Scheme 104

Transaxle Electronic Control System Wiring Diagram (2001 Cavalier & Sunfire - 2.2L & 2.4L). Scheme 105

Transaxle Electronic Control System Wiring Diagram (2001 Malibu - 3.1L). Scheme 106

Transaxle Electronic Control System Wiring Diagram (2002 Alero & Grand Am - 2.2L). Scheme 107

Transaxle Electronic Control System Wiring Diagram (2002 Alero & Grand Am - 3.4L). Scheme 108

Transaxle Electronic Control System Wiring Diagram (2002 Cavalier & Sunfire - 2.2L). Scheme 109

Transaxle Electronic Control System Wiring Diagram (2002 Cavalier & Sunfire - 2.4L). Scheme 110

Transaxle Electronic Control System Wiring Diagram (2002 Malibu - 3.1L). Scheme 111

See also:
• PC SOLENOID VALVE DUTY CYCLE
• SYMPTOM DIAGNOSIS
• PRELIMINARY INSPECTION
• DIAGNOSTIC TROUBLE CODE DEFINITIONS
• P0218
• P0502
• P0503
• P0705
• P0711
• P0712
• P0713
• P0716
• P0717
• P0719
• P0724
• P0730
• P0741
• P0742
• P0748
• P0751
• P0752
• P0753
• P0756
• P0757
• P0758
• P1810
• P1811
• P1815
• P1816
• P1817
• P1818
• P1860
• P1887
• TROUBLE SHOOTING
• CLEARING DIAGNOSTIC TROUBLE CODES
• HYDRAULIC PRESSURE TESTS