Automatic Transaxle Diagnosis - 4t80-e Cadillac Seville V

IDENTIFICATION

All transaxles have a nameplate attached to the rear face of transaxle case. A transaxle VIN number is also stamped into right rear surface of case. (Scheme 71)

Scheme 71

INTRODUCTION

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

The 4T80-E is a fully automatic front wheel drive electronically controlled transaxle. The 4T80-E provides four forward ranges including overdrive. The Powertrain Control Module (PCM) controls shift points by means of two shift solenoids. Three gear-type oil pumps supply the oil pressure. The PCM regulates oil pressure by means of a Pressure Control (PC) solenoid. The PCM controls the shift schedule and the Torque Converter Clutch (TCC) apply rates. Many sensor inputs also influence the shift schedule and the TCC apply rates.

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. OD - 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. D - 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 second provides acceleration and engine braking.
7. 1 - Manual low provides maximum engine braking.

ADAPT FUNCTION

The 4T80-E transaxle uses a line pressure control system that has the ability to adapt line pressure to compensate for normal wear of the following parts

1. The clutch fiber plates.
2. The springs and seals.
3. The apply bands.

The PCM maintains the following adapt parameters for the transaxle

Upshift Adapts

The PCM monitors the transaxle Input Speed Sensor (ISS) and the Vehicle Speed Sensor (VSS) during commanded shifts to determine if a shift is occurring too fast or too slow. The PCM adjusts the signal to the Pressure Control (PC) solenoid valve to maintain a set shift feel.

Steady State Adapts

The PCM monitors the ISS and the VSS after a shift, and calculates the amount of shift time in that gear. The PCM then adjusts the signal to the PC solenoid valve to maintain shift time below a set amount.

Clearing Transmission Adaptive Pressure

Note. The transaxle may experience harsh, soft or mushy shifts for up to two days after the adapts are cleared.

Transmission adapts must be cleared whenever the transaxle is overhauled or replaced. To clear transmission adapts, select the following

1. Scan Tool
2. SPECIAL FUNCTIONS
3. TRANSMISSION OUTPUT CONTROLS
4. CLEAR TAP

TRANSAXLE COMPONENTS & SYSTEMS

Note. For transaxle electronic component locations (Scheme 72)

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. 4th and low-reverse band assemblies.
4. Forward, coast, 2nd and 3rd multiple disc clutches.
5. Two planetary gear sets.
6. Two sprag clutches (forward and 2nd).
7. One roller clutch (low).
8. Three fluid pumps.
9. Two control valve assemblies.
10. A final drive assembly with a bolted-on case extension.

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 Modulation (TCC PWM) solenoid valve.
3. A Pressure Control (PC) solenoid valve.
4. A Transmission Fluid Temperature (TFT) sensor.
5. Two speed sensors (input shaft and vehicle speed sensors).
6. An internal mode switch.
7. A Transmission Fluid Pressure (TFP) manual valve position switch.
8. A transaxle wiring harness.
9. A transaxle wiring extension harness.

ELECTRONIC COMPONENTS

Note. For transaxle electronic component locations (Scheme 72)

Torque Converter Clutch Pulse Width Modulation Solenoid Valve

The Torque Converter Clutch (TCC) solenoid valve is a three-port assembly which uses negative duty cycle, Pulse Width Modulation (PWM) to control the rate of TCC apply and release. The solenoid's ability to ramp apply and release pressures results in a smoother apply and release of the TCC in all conditions.

The TCC PWM solenoid valve is a normally closed valve, mounted to the upper control valve body and used to control the position of the TCC apply valve.

Pressure Control Solenoid Valve

A Pressure Control (PC) solenoid valve (also known as a force motor) is a three-port, spool valve, electronic pressure regulator. The solenoid controls pressure based on a flow of current through its coil-winding. The solenoid controls main line pressure by moving a pressure regulator valve against spring pressure.

The position of the PC solenoid valve is controlled by a combination of two methods: high side control and low side control. One terminal of the solenoid receives a fixed frequency signal of 614.0 Hz. This signal varies in positive duty cycle. This feed circuit is called Force High.

The opposite terminal of the PC solenoid valve is called Force Low. Force Low provides a ground for the solenoid.

This combination of Force High and Force Low circuitry controls the actual current through the PC solenoid valve. This advanced control method assures instantaneous control of line pressure when changes occur in the TP sensor and adaptive learning.

1-2 & 2-3 Shift Solenoid Valves

A shift solenoid valve is a two-port, feed-bleed device consisting of a coil/plunger-ball assembly. The solenoid assembly works with an orifice to pressurize the shift valve end chamber when voltage is applied to its coil. The controlled pressure then moves the shift valve against a spring, causing a shift to occur. When voltage is no longer applied, the chamber opens to exhaust and the opposite shift valve action occurs. Shift solenoids eliminate the need for throttle valve and governor pressures to control shift valve operation.

The 4T80-E transmission uses two shift solenoid valves (the 1-2 and 2-3), which are attached to the lower valve body.

Note. If both solenoids lose power, only 2nd gear will result.

The shift solenoid valve should energize at a voltage of 7.5 volts or more, measured across the terminals. The shift solenoid valve should de-energize when voltage is one volt or less.

Transmission Fluid Pressure Manual Valve Position Switch

The Transmission Fluid Pressure (TFP) manual valve position switch assembly consists of two normally open pressure switches. The assembly is attached to the lower control valve body. The PCM supplies ignition voltage on the two range signal circuits, signal circuit "A" and signal circuit "C". By grounding one of the switches with fluid pressure from the manual valve, the PCM detects a garage shift from Park/Neutral to Reverse or Park/Neutral to Drive. See TFP MANUAL VALVE POSITION SWITCH LOGIC table. This information is used by the PCM to adjust line pressure during garage shifts.

TFP MANUAL VALVE POSITION SWITCH LOGIC (1)

Vehicle Speed Sensor

The Vehicle Speed Sensor (VSS) is mounted on the transaxle case extension facing toward the right wheel. This sensor consists of a permanent magnet surrounded by a coil of wire. The sensor mounts into the extension, and maintains a slight air gap (0.045-0.109") between itself and a rotor which is located on the differential. The VSS measures the speed of the rotor, which contains 31 teeth. As the differential rotates, an AC signal is induced in the VSS. The AC signal varies in frequency and voltage output

1. Low speed Low Hz and voltage amplitude.
2. High speed High Hz and voltage amplitude.

This input is used for TCC, line pressure, shift timing and torque management controls. Output voltage varies with speed from a minimum of 0.5 volts AC at 100 RPM, to more than 100 volts AC at 8000 RPM.

Input Speed Sensor

The Input Speed Sensor (ISS) is mounted in the case cover facing the drive sprocket. The sensor consists of a permanent magnet surrounded by a coil of wire. The sensor mounts into the case and maintains a slight air gap (0.045-0.109") between itself and the drive sprocket. An AC voltage signal is induced in the input sensor by rotating the drive sprocket, which contains 39 teeth cut in its outside diameter. The voltage output and frequency varies with drive sprocket speed

1. Low speed Low Hz and voltage amplitude.
2. High speed High Hz and voltage amplitude.

Inside the PCM, this analog signal changes to a digital signal. The processor then compares this digital signal to a fixed clock signal within the PCM to determine the actual turbine speed. The PCM uses input speed for control of line pressure, speed calculation and gear ratio.

Sensor resistance should be 1300-1950 ohms when measured at 68-212°F (20-100°C). Output voltage will vary with speed from a minimum of 0.5 volts AC at 100 RPM, to more than 100 volts AC at 8000 RPM.

Transmission Fluid Temperature Sensor

The Transmission Fluid Temperature (TFT) sensor controls TCC and line pressure. The TFT sensor attaches to the upper control valve assembly. The TFT signals the PCM regarding transmission fluid temperature. The sensor is a negative temperature coefficient thermistor which receives a 5-volt signal from the PCM.

When the temperature is cold, the sensor resistance is high; therefore, the PCM sees a high signal voltage. As the fluid warms, the sensor resistance decreases, and the voltage drop across the sensor becomes lower.

The TFT sensor may be tested with an ohmmeter across terminals "L" and "M" of the transaxle in-line 20-way connector. Nominal ohm readings at specified temperatures are given in voltage levels at the PCM. (Scheme 126)

The temperature sensor mode operates in the following two ways

1. Hot Mode Enable Above 266°F (130°C) and TCC on in 3rd gear at 30 MPH with 0-10 degree throttle angle; and 4th gear at 39 MPH with 0-10 degree throttle angle. This reduces transmission temperature by decreasing the amount of heat generated in the torque converter. It also provides maximum cooling by routing transmission fluid directly to the transmission cooler in the engine radiator.
2. Super Hot Mode Disable On 275 HP RPO LD8 Engine Above 284°F (140°C) and TCC off with 4th gear inhibited. Super hot is a condition where a hot engine adds heat to the transaxle through the transmission cooler. By inhibiting TCC and 4th gear operation, the engine works under less load. This reduces the heat added to the transmission fluid by the transmission cooler. As both the engine and the transaxle cool off, TCC and 4th gear are permitted again.

A PCM internal shunt circuit comes into play as the temperature increases beyond 122°F (50°C). As the temperature decreases, the internal shunt comes out at 104°F (40°C). There is a 18°F (10°C) overlap.

Internal Mode Switch

The internal mode switch is a multi-signal switch assembly attached to the lower control valve body. The internal mode switch consists of a set of stationary contacts and a set of sliding contacts. The manual valve link assembly connects the sliding contacts to the manual valve. Electrically, the stationary contacts are connected to ground through the internal mode switch ground circuit, and the sliding contacts are connected to the PCM through four internal mode switch signal circuits. The signal voltage at the PCM is high (ignition voltage) when a signal circuit is open, and low (zero volts) when a signal circuit is closed to ground. Each gearshift lever position grounds one or more of the signal circuits in a unique pattern that enables the PCM to determine gearshift lever position. See INTERNAL MODE SWITCH LOGIC table.

INTERNAL MODE SWITCH LOGIC (1)

Transaxle Electrical Connector

The transaxle in-line 20-way 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. 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.

Scheme 72

POWERTRAIN CONTROL MODULE

The PCM controls ignition, fuel and emission devices related to engine and transaxle operation. PCM receives electronic signals from sensors and switches. Input signals enable PCM to determine when to operate various relays and solenoids related to engine and transaxle control. PCM utilizes 2 different colored 80-way connectors. (Scheme 129)- (Scheme 136).

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) may illuminate if malfunction occurs. Vehicle should not be driven for extended periods in limp-in mode.

ELECTRONIC CONTROL SYSTEM

The PCM constantly monitors the information from various sensors and controls the systems that affect vehicle performance and emissions. The PCM also performs the diagnostic functions for those systems. The PCM can recognize operational problems and alert the driver through the Malfunction Indicator Lamp (MIL) when a malfunction has occurred. When a malfunction is detected, the PCM stores a Diagnostic Trouble Code (DTC) which helps to identify problem areas. This is done to aid the technician in making repairs.

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 73)- (Scheme 116). 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

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. Diagnostic Trouble Codes (DTC) 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. Check the garage shifts as follows: Apply the brake pedal and ensure the parking brake is set. Move the gearshift lever from Park to Reverse, Reverse to Neutral, then Neutral to Drive. Pause 2 to 3 seconds in each gear position. Verify the gear engagements are immediate and not harsh.
7. Monitor transaxle range on the scan tool as follows: Apply the brake pedal and ensure the parking brake is set. Move the gearshift lever through all ranges. Pause 2 to 3 seconds in each range. Return gearshift lever to Park. Verify that all selector positions match the scan tool display.
8. Check throttle angle input as follows: 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 angle of 12, 25 or 50 percent. See «SHIFT SPEED SPECIFICATIONS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-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 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»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-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»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-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 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 Overdrive position.
2. Accelerate the vehicle to speeds of 40-55 MPH in 4th gear.
3. Quickly increase throttle angle to 100 percent.
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 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 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 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 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»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .

Manual Gear Range Selection (Reverse)

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

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 Gear Range Selection (1st)

Note. Perform the following test using 10-15 percent throttle angle.

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 Gear Range Selection (2nd)

Note. Perform the following test using 10-15 percent throttle angle.

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 Gear Range Selection (3rd)

Note. Perform the following test using 10-15 percent throttle angle.

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.

Scheme 117

TORQUE CONVERTER DIAGNOSIS

The Torque Converter Clutch (TCC) is applied by fluid pressure, which is controlled by a 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 gearshift lever in Drive position.
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 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.

Line Pressure Adapter & Gauge Installation

1. Remove the air cleaner assembly.
2. Raise the vehicle and suitably support the vehicle.
3. Remove the line pressure plug.
4. Install Pressure Gauge Adapter (J-21867-100) using a ratchet box wrench. Tighten the adapter so that the insert hole for the dowel rod is in a one o'clock position. (Scheme 118)
5. Lower the vehicle.
6. Install the dowel rod from Line Pressure Adapter Kit (J-21867-94).
7. Attach a line pressure gauge and hose to the dowel rod fitting.
8. Secure the hose in a safe position to avoid damage to the tools and vehicle during the line pressure testing.
9. When you have completed the testing procedure, remove the line pressure gauge and hose from the dowel rod fitting.
10. Remove the dowel rod.
11. Raise the vehicle and suitably support the vehicle.
12. Remove pressure gauge adapter using a ratchet box wrench.
13. Install the line pressure plug.
14. Lower the vehicle.
15. Install the air cleaner assembly.

Scheme 118

Line Pressure

Line pressures are calibrated for two sets of gear ranges: Drive, Park or Neutral, and Reverse. This allows the transmission line pressure to be appropriate for different pressure needs in different gear ranges. See LINE PRESSURE RANGE SPECIFICATIONS table.

1. Hook up the scan tool.
2. Start the engine and set the parking brake.
3. Check for a DTC P0748 malfunction code from the pressure control solenoid. Check for other malfunction codes.
4. Repair the vehicle if necessary. Include the following areas: Inspect the fluid level. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Inspect the manual linkage at the transaxle. Install the pressure gauge adapter. See «LINE PRESSURE ADAPTER & GAUGE INSTALLATION»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__line-pressure-adapter-gauge-installation) .
5. Put the gearshift lever in Park and set the parking brake.
6. Start the engine and allow the engine to warm up at idle.
7. Select SPECIAL FUNCTIONS on the scan tool.
8. Select TRANS OUTPUT CONTROLS/PRESSURE CONTROL SOLENOID on the scan tool.
9. Compare your data to line pressure specifications. See «PC SOLENOID CURRENT & LINE PRESSURE SPECIFICATIONS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) table. This line pressure is valid for PC solenoid overrides with the vehicle stopped at idle and in Park-Neutral.

If pressure readings differ greatly from the line pressure specifications, see SYMPTOM DIAGNOSIS under TROUBLE SHOOTING.

LINE PRESSURE RANGE SPECIFICATIONS

PC SOLENOID CURRENT & LINE PRESSURE SPECIFICATIONS

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 connector.
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

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»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__diagnostic-trouble-code-definitions) . If not, see «SYMPTOM DIAGNOSIS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__symptom-diagnosis) under TROUBLE SHOOTING.

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 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 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 FLUID OVERTEMPERATURE

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 up, the sensor resistance becomes lower. The PCM uses transmission fluid temperature information to control torque converter clutch apply and release, line pressure, and shift time.

If the PCM detects a high transmission fluid temperature for an extended period of time on the TFT sensor circuit, then DTC P0218 sets. DTC P0218 is a type "C" DTC.

Conditions For Running DTC P0218

DTC will run under the following condition

1. The transmission fluid temperature is -36-289°F (-38-143°C).

Conditions For Setting DTC P0218

DTC will set under the following condition

1. The transmission fluid temperature is greater than 270°F (132°C) for 10 minutes.

Action Taken By PCM

PCM performs the following actions if DTC is set

1. The PCM does not illuminate the MIL.
2. TRANSMISSION HOT message displays on the driver information center.
3. The PCM freezes shift adapt functions.
4. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
5. The PCM stores DTC P0218 in PCM history.

Conditions For Clearing DTC P0218

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. The transmission fluid temperature is less than 266°F (130°C) for 5 seconds.
3. A scan tool can clear the DTC.
4. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
5. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

The number listed below refers to step number in the diagnostic procedure

1. 2 This step ensures that the transmission fluid is at the proper level. A low fluid level may cause an overtemperature condition.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Inspect the following items: The transmission cooling system for radiator air flow restrictions, or pinched, plugged, twisted or leaking cooler lines. The transmission fluid and filter for fluid that has become contaminated with antifreeze, a clogged filter or a filter that is not seated correctly, or clogged scavenge screens. The upper control valve body for converter clutch control valve stuck off or fluid circuits leaking or blocked by debris. Repair any of the above items as necessary. Did you complete the repair? If so, go to next step.
4. Perform the following procedure to verify the repair: Install a scan tool. 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 266°F (130°C). Select SPECIFIC DTC. Enter DTC P0218. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Ask the customer about overloading the vehicle, exceeding the trailer-towing limit, or towing in Overdrive.

DTC P0502: VEHICLE SPEED SENSOR 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 VSS is a permanent magnet generator attached to the transaxle case. The final drive assembly has a toothed wheel, VSS rotor. As the final drive assembly rotates, an AC voltage is induced and transmitted to the PCM. The PCM converts the AC voltage into a digital signal. The PCM uses the vehicle speed to determine shift timing, torque converter clutch apply and release, and gear ratio.

If the PCM detects a low vehicle speed and a high input shaft speed while in a drive range, then DTC P0502 sets. DTC P0502 is a type "B" DTC.

Conditions For Running DTC P0502

DTC will run under the following conditions

1. No TP sensor DTCs P0121, P0122 or P0123.
2. No VSS DTC P0503.
3. No ISS DTCs P0716 or P0717.
4. No internal mode switch DTCs P1820, P1822, P1823, or P1825.
5. The system voltage is 8-18 volts.
6. The engine run time is greater than 5 seconds.
7. The transaxle is not in Park or Neutral.
8. The throttle angle is 12 percent or greater.
9. The engine torque is 44-291 ft. lbs. (60-395 N.m).
10. The input shaft speed is 1000-5000 RPM.

Conditions For Setting DTC P0502

DTC will set under the following condition

1. On models with RPO code "LD8", the output shaft speed is 280 RPM or less for 3 seconds.
2. On models with RPO code "L37", the output shaft speed is 334 RPM or less for 3 seconds.

The PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM freezes shift adapt functions.
4. The PCM calculates vehicle speed from the ISS and commanded gear.
5. The PCM applies the TCC in 3rd gear when in hot mode.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P0502 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0502

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 2 This step tests for DTCs and for a vehicle speed signal. It is important to record freeze frame and failure record information before proceeding further.
2. 5 This step tests for a resistance value greater than 1950 ohms which would indicate an open in the high signal circuit, the low signal circuit or the VSS.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Raise and support the drive wheels. Start and idle the engine. Place the gearshift lever in Drive position. Select OSS on the scan tool. With the drive wheels rotating, does the OSS RPM increase when the wheel speed increases? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect PCM connector C1. Using the Terminal Test Kit (J-35616-A), connect a DVOM between PCM connector C1 terminals No. 56 and 57. Select AC scale on the DVOM. Place the gearshift lever in Neutral before rotating the drive wheel. Rotate the right front drive wheel by hand. Can a voltage greater than 0.5 volt AC be obtained? If so, go to step 14 . If not, go to next step.
4. Leave the DVOM test leads connected. Measure circuit resistance. Is the circuit resistance 1300-1950 ohms? If so, go to step 8 . If not, go to next step.
5. Is the circuit resistance greater than 1950 ohms? If so, go to step 11 . If not, go to next step.
6. Leave the DVOM test leads connected. Disconnect the wiring harness connector at VSS. Is the circuit resistance less than 1300 ohms? If so, go to next step. If not, go to step 13 .
7. Test the VSS high (400) and low (401) signal circuits for being shorted together. Did you find and correct the condition? If so, go to step 15 .
8. Test the VSS high signal circuit (400) for a short to ground. Did you find and correct the condition? If so, go to step 15 . If not, go to next step.
9. Reconnect PCM connector C1. Connect the DVOM to VSS connector terminals "A" and "B" Select DC scale on the DVOM. Turn ignition on, engine off. Does the DVOM display system voltage? If so, go to next step. If not, go to step 12 .
10. Test the VSS high signal circuit (400) for a short to voltage. Did you find and correct the condition? If so, go to step 15 .
11. Test the VSS high signal circuit (400) for an open. Test the VSS low signal circuit (401) for an open. Did you find and correct a condition? If so, go to step 15 . If not, go to step 13 .
12. Remove the VSS. Inspect the VSS and the transaxle for the following conditions: Incorrect VSS. VSS damage. Excessive VSS-to-speed sensor rotor gap. Incorrect speed sensor rotor alignment. Speed sensor rotor damage. Repair any of the above conditions as necessary. Did you complete the repair? If so, go to step 15 .
13. Replace the VSS. See «VEHICLE SPEED SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 15 .
14. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
15. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle to achieve a OSS of greater than 1855 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 .

Inspect wiring for poor connections. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

DTC P0503: VEHICLE SPEED SENSOR 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 VSS is a permanent magnet generator attached to the transaxle case. The final drive assembly has a toothed wheel, VSS rotor. As the final drive assembly rotates, an AC voltage is induced and transmitted to the PCM. The PCM converts the AC voltage into a digital signal. The PCM uses vehicle speed to determine shift timing, torque converter clutch apply and release, and gear ratio.

If the PCM detects a loss of vehicle speed while the vehicle is in motion, then DTC P0503 sets. DTC P0503 is a type "B" DTC.

Conditions For Running DTC P0503

DTC will run under the following conditions

1. No ISS DTCs P0716 or P0717.
2. No internal mode switch DTCs P1820, P1822, P1823, or P1825.
3. No 1-2 shift solenoid DTC P1843.
4. The engine run time is greater than 5 seconds.
5. The transaxle is not in Park or Neutral.
6. The time since the gearshift lever change is greater than 6 seconds.
7. The input speed has not changed by 500 RPM or greater for at least 4.8 seconds.
8. On models with RPO code "LD8", the output speed is greater than 1244 RPM and has not increased by 500 RPM or greater for at least 2 seconds.
9. On models with RPO code "L37", the output speed is greater than 1484 RPM and has not increased by 500 RPM or greater for at least 2 seconds.

Conditions For Setting DTC P0503

DTC will set under the following condition

1. On models with RPO code "LD8", the output speed drops 1089 RPM or greater for at least one second.
2. On models with RPO code "L37", the output speed drops 1299 RPM or greater for at least one second.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM freezes shift adapt functions.
4. The PCM calculates vehicle speed from the ISS and commanded gear.
5. The PCM applies the TCC in 3rd gear when in hot mode.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P0503 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0503

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 2 This step tests for DTCs and for a vehicle speed signal. It is important to record freeze frame and failure record information before proceeding further.
2. 5 This step tests for a resistance value greater than 1950 ohms which would indicate an open in the high signal circuit, the low signal circuit or the VSS.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Start and idle the engine. Place the gearshift lever in Drive position. Select OSS on the scan tool. With the drive wheels rotating, does the OSS RPM increase when the wheel speed increases? If so, go see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect PCM connector C1. Using the Terminal Test Kit (J-35616-A), connect a DVOM between PCM connector C1 terminals No. 56 and 57. Select AC scale on the DVOM. Place the gearshift lever in Neutral before rotating the drive wheel. Rotate the right front drive wheel by hand. Can a voltage greater than 0.5 volt AC be obtained? If so, go to step 14 . If not, go to next step.
4. Leave the DVOM test leads connected. Measure circuit resistance. Is the circuit resistance 1300-1950 ohms? If so, go to step 8 . If not, go to next step.
5. Is the circuit resistance greater than 1950 ohms? If so, go to step 11 . If not, go to next step.
6. Leave the DVOM test leads connected. Disconnect the VSS connector at the transaxle. Is the circuit resistance less than 1300 ohms? If so, go to next step. If not, go to step 13 .
7. Test the VSS high (400) and low (401) signal circuits for being shorted together. Did you find and correct the condition? If so, go to step 15 .
8. Test the VSS high signal circuit (400) for a short to ground. Did you find and correct the condition? If so, go to step 15 . If not, go to next step.
9. Reconnect PCM connector C1. Using the terminal test kit, connect the DVOM test leads to VSS harness connector terminals "A" and "B". Select DC scale on the DVOM. Turn ignition on, engine off. Does the DVOM display system voltage? If so, go to next step. If not, go to step 12 .
10. Test the VSS high signal circuit (400) for a short to voltage. Did you find and correct the condition? If so, go to step 15 .
11. Test the VSS high (400) and low (401) signal circuits for an open. Did you find and correct a condition? If so, go to step 15 . If not, go to step 13 .
12. Remove the VSS. Inspect the VSS and the transaxle for the following conditions: Incorrect VSS. VSS damage. Excessive VSS to speed sensor rotor gap. Incorrect speed sensor rotor alignment. Speed sensor rotor damage. Repair any of the above conditions as necessary. Did you complete the repair? If so, go to step 15 .
13. Replace the VSS. See «VEHICLE SPEED SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 15 .
14. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
15. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Road test the vehicle and ensure that the OSS is greater than 1198 RPM and does not drop 175 RPM or greater for 2 seconds. Select SPECIFIC DTC. Enter DTC P0503. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

DTC P0711: TRANSMISSION FLUID TEMPERATURE SENSOR CIRCUIT PERFORMANCE

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 up, the sensor resistance decreases. This diagnostic monitors the TFT sensor circuit. The circuit may be functional, but not in the normal operating range. This diagnostic indicates stuck, erratic, intermittent, or skewed values, indicating poor system performance. The transmission fluid temperature range is -40 to 305°F (-40 to 151°C).

If the PCM detects an intermittent voltage or no voltage change in the TFT sensor circuit, then DTC P0711 sets. DTC P0711 is a type "C" DTC.

Conditions For Running DTC P0711

DTC will run under the following conditions

1. No engine coolant temperature DTCs P0116, P0117, P0118, P1114 or P1115.
2. No VSS DTCs P0502 or P0503.
3. No ISS DTCs P0716 or P0717.
4. The system voltage is 8-18 volts.
5. The engine run time is greater than 5 seconds.
6. The transmission fluid temperature is -36 to 289°F (-38 to 143°C).

Condition No. 1 For Setting DTC P0711

DTC will set under the following conditions

1. DTC P0711 has not passed this ignition cycle.
2. The engine coolant temperature is 158°F (70°C) or greater and has changed by at least 90°F (50°C) since start-up.
3. The transmission fluid temperature at start-up is -36 to 70°F (-38 to 21°C).
4. The vehicle speed is 5 MPH or greater for 15 minutes cumulatively.
5. The TCC slip is 120 RPM or greater for 15 minutes cumulatively.
6. The transmission fluid temperature has not changed by greater than 4°F (2°C) since start-up for one minute and 40 seconds.

Condition No. 2 For Setting DTC P0711

DTC will set under the following conditions

1. DTC P0711 has not passed this ignition cycle.
2. The engine coolant temperature is 158°F (70°C) or greater and has changed by at least 90°F (50°C) since start-up.
3. The transmission fluid temperature at start-up is 264-289°F (129-143°C).
4. The vehicle speed is 5 MPH or greater for 15 minutes cumulatively.
5. The TCC slip is 120 RPM or greater for 15 minutes cumulatively.
6. The transmission fluid temperature has not changed by greater than 4°F (2°C) since start-up for one minute and 40 seconds.

Condition No. 3 For Setting DTC P0711

DTC will set under the following conditions

1. The transmission fluid temperature has changed by 36°F (20°C) or greater within 200 milliseconds; 14 times within 7 seconds.

PCM performs the following if DTC is set

1. The PCM does not illuminate the MIL.
2. The PCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time.
3. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
4. The PCM stores DTC P0711 in PCM history.

Conditions For Clearing DTC P0711

DTC P0711 will clear under the following conditions

1. A scan tool can clear the DTC.
2. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
3. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 5 This step tests for an intermittent short or open condition in the engine wiring harness. The test light is used as a resistor in the circuit.
2. 6 This step determines if the PCM or the TFT sensor is causing a steady, unchanging transmission fluid temperature reading.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Select TRANS FLUID TEMP on the scan tool. 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°C (4°F) in one minute and 40 seconds since start-up. The transmission fluid temperature changes by 20°C (36°F) or greater in 0.200 second, 14 times within 7 seconds, indicating an unrealistic fluid temperature change. Did either of the fail conditions occur? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
4. Did the scan tool display a condition in which the transmission fluid temperature does not change by greater than 4°F (2°C) in one minute and 40 seconds since start-up? If so, go to step 6 . If not, go to next step.
5. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Using Terminal Test Kit (J-35616-A), connect a test light between jumper harness terminals "L" and "M". Turn ignition on, engine off. While observing the scan tool display, move or wiggle the engine wiring harness from PCM connector C2 to the transaxle in-line 20-way connector. Does the 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 the transaxle in-line 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 4°F (2°C) in one minute and 40 seconds since start-up? If so, go to step 11 . If not, go to step 10 .
7. Test the TFT sensor signal circuit (1227) for an intermittent open or short condition between the PCM connector C2 and the transaxle in-line 20-way connector. Test the TFT sensor low reference circuit (2762) for an intermittent open or short condition between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct a condition? If so, go to step 12 . If not, go to step 11 .
8. Test the TFT sensor signal circuit (1227) for an intermittent open or short condition between the transaxle in-line 20-way connector and the TFT sensor. Test the TFT sensor low reference circuit (452) for an intermittent open or short condition between the transaxle in-line 20-way connector and the TFT sensor. Did you find a condition? If so, go to next step. If not, go to step 10 .
9. Replace the transaxle internal wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 12 .
10. Replace the TFT sensor. See «TFT SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__tft-sensor) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 12 .
11. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
12. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle. The transmission fluid temperature is -36 to 289°F (-38 to 143°C). The transmission fluid temperature changes by greater than 4°F (2°C) since start-up. The transmission fluid temperature does not change by 36°F (20°C) or greater within 200 milliseconds. 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. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

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 negative coefficient thermistor whose resistance value changes based on temperature. The PCM provides a 5-volt reference to the sensor. A high fluid temperature or a short to ground on the signal circuit results in low signal voltage. The transmission fluid temperature operating range is -40 to 305°F (-40 to 151°C).

If the PCM detects a continuous short to ground in the TFT sensor circuit, then DTC P0712 sets. DTC P0712 is a type "C" DTC.

Conditions For Running DTC P0712

DTC will run under the following condition

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.

Conditions For Setting DTC P0712

DTC will set under the following condition

1. The PCM detects a transmission fluid temperature of 300°F (149°C) or greater for 10 seconds.

PCM performs the following if DTC is set

1. The PCM does not illuminate the MIL.
2. The PCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time.
3. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
4. The PCM stores DTC P0712 in PCM history.

Conditions For Clearing DTC P0712

DTC will clear under the following conditions

1. A scan tool can clear the DTC.
2. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
3. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 2 This step verifies DTC P0712 by indicating a short to ground. If the scan tool does not display a transmission fluid temperature equal to or greater than 300°F (149°C), then the DTC is intermittent.
2. 3 This step isolates the transaxle. If the scan tool displays a transmission fluid temperature less than -36°F (-38°C), then the engine wiring harness is good.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Select TRANS FLUID TEMP on scan tool. Does the scan tool display a transmission fluid temperature less than 300°F (149°C)? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Does the scan tool display a transmission fluid temperature less than -36°F (-38°C)? If so, go to step 5 . If not, go to next step.
4. Test the TFT sensor signal circuit (1227) for a short to ground between the PCM connector C2 and the transaxle in-line 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) on the transaxle side of the transaxle in-line 20-way connector. Using a DVOM and Terminal Test Kit (J-35616-A), measure the resistance between jumper harness terminals "L" and "M". Is the resistance 3088-3942 ohms at 68°F (20°C) to 159-198 ohms at 176°F (80°C)? If so, go to next step. If not, go to step 7 .
6. Measure the resistance between jumper harness terminal "L" and ground. Is the resistance less than 100 ohms? If so, go to step 9 . If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
7. Disconnect the wiring harness connector from the TFT sensor. Measure the resistance between terminal "L" and all other jumper harness terminals. Is the resistance between jumper harness terminal "L" and any other terminal less than 100 ohms? If so, go to step 9 . If not, go to next step.
8. Replace the TFT sensor. See «TFT SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__tft-sensor) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 11 .
9. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 11 .
10. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
11. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Turn ignition on, engine off. The transmission fluid temperature must be 291°F (144°C) or less for 2 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. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

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 negative coefficient thermistor whose resistance value changes based on temperature. The PCM provides a 5-volt reference to the sensor. A low fluid temperature, an open TFT sensor or an open sensor circuit results in high signal voltage. The TFT sensor operating range is -40°F to 304°F (-40°C to 151°C).

If the PCM detects a continuous open or a short to power on the TFT sensor circuit, then DTC P0713 sets. DTC P0713 is a type "C" DTC.

Conditions For Running DTC P0713

DTC will run under the following conditions

1. No VSS DTCs P0502 or P0503.
2. No ISS DTCs P0716 or P0717.
3. The system voltage is 8-18 volts.
4. The engine run time is greater than 5 seconds.
5. The output shaft speed is 200 RPM or greater for 5 minutes cumulatively.
6. The TCC slip speed is 50 RPM or greater for 6 minutes and 40 seconds cumulatively.

Conditions For Setting DTC P0713

DTC will set under the following conditions

1. The PCM detects a reading of -40°F (-40°C) or less for 6 seconds.

PCM performs the following if DTC is set

1. The PCM does not illuminate the MIL.
2. The PCM calculates a default transmission fluid temperature based on engine coolant temperature, intake air temperature and engine run time.
3. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
4. The PCM stores DTC P0713 in PCM history.

Conditions For Clearing DTC P0713

DTC will clear under the following conditions

1. A scan tool can clear the DTC.
2. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
3. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 5 This step tests the TFT sensor signal circuit for being shorted to another circuit within the transaxle. If the TFT sensor signal circuit shorts to another circuit, which is carrying voltage greater than 5 volts, the TFT sensor would become open.
2. 6 This step tests the TFT sensor signal circuit for being shorted to voltage, which would be the cause for the open in the TFT sensor.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the DTC failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Select TRANS FLUID TEMP on the scan tool. Does the scan tool display a transmission fluid temperature less than -38°F (-39°C)? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the transaxle side of the transaxle in-line 20-way connector. Using a DVOM and Terminal Test Kit (J-35616-A), measure the resistance between jumper harness terminals "L" and "M". Is the resistance less than 100 k/ohms? If so, go to step 7 . If not, go to next step.
4. Test the TFT sensor signal circuit (1227) for an open between the transaxle in-line 20-way connector and the TFT sensor. Test the TFT sensor low reference circuit (452) for an open between the transaxle in-line 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 the resistance between terminal "L" and all other terminals of the jumper harness. Is the resistance between terminal "L" and any other terminal less than 1000 ohms? If so, go to step 10 . If not, go to next step.
6. Test the TFT sensor signal circuit (1227) for a short to voltage between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 12 . If not, go to step 9 .
7. Test the TFT sensor signal circuit (1227) for an open between the PCM connector C2 and the transaxle in-line 20-way connector. Test the TFT sensor low reference circuit (2762) for an open between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct an open condition? If so, go to step 12 . If not, go to step 11 .
8. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 12 .
9. Replace the TFT sensor. See «TFT SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__tft-sensor) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 12 .
10. Replace the transaxle wiring harness and the TFT sensor. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) and «TFT SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__tft-sensor) under REMOVAL & INSTALLATION. Did you complete the replacements? If so, go to step 12 .
11. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
12. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Turn ignition on, engine off. The transmission fluid temperature must be greater than -40°F (-40°C) for 6 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. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

DTC P0716: INPUT SPEED SENSOR CIRCUIT PERFORMANCE

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

The Input Speed Sensor (ISS) is a permanent magnet generator. The ISS mounts in the transaxle case facing the drive sprocket of the input shaft. As the drive sprocket rotates, an AC voltage is induced and transmitted to the PCM. The PCM converts the AC voltage into a digital signal. The PCM uses the input ISS signal to determine shift timing, torque converter clutch slip speed and gear ratio.

If the PCM detects an unrealistic change in RPM from the ISS, then DTC P0716 sets. DTC P0716 is a type "B" DTC.

Conditions For Running DTC P0716

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 valve performance DTCs P0751 or P0752.
5. No 1-2 shift solenoid valve electrical DTCs P1842 or P1843.
6. The system voltage is 8-18 volts.
7. The engine run time is greater than 5 seconds.
8. The internal mode switch indicates "D4".
9. The throttle angle is 12 percent or greater.
10. The vehicle speed is 10 MPH or greater.
11. The input shaft speed is greater than 1050 RPM for at least 2 seconds.
12. The input shaft speed has not increased by 500 RPM or greater for at least 2 seconds.

Conditions For Setting DTC P0716

DTC will set under the following conditions

1. The input shaft speed drops by 1000 RPM or greater for at least one second.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM inhibits TCC engagement.
4. The PCM calculates input shaft speed from vehicle speed and commanded gear.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
6. The PCM stores DTC P0716 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0716

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step tests the ISS for correct resistance.
2. 8 This step tests the ISS high signal circuit for being shorted to another circuit within the transaxle.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. 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»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the transaxle side of the transaxle in-line 20-way connector. Using a DVOM and Terminal Test Kit (J-35616-A), measure the resistance between jumper harness terminals "S" and "V". Is the resistance 1300-1950 ohms? If so, go to step 7 . If not, go to next step.
4. Is the resistance greater than 1950 ohms? If so, go to next step. If not, go to step 6 .
5. Test the ISS high signal circuit (1230) for high resistance or an open between the transaxle in-line 20-way connector and the ISS. Test the ISS low signal circuit (1231) for a high resistance or an open between the transaxle in-line 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 (1230) and low (1231) signal circuits for being shorted together between the transaxle in-line 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 the 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 terminals except terminal "V" of the jumper harness. 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 (1230) for high resistance, an open, a short to ground or a short to voltage between the PCM connector C1 and the transaxle in-line 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 (1231) for high resistance or an open between the PCM connector C1 and the transaxle in-line 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 wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 14 .
12. Replace the ISS. See «INPUT SPEED SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 14 .
13. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
14. Perform the following procedure in order to verify the repair: Select DTC. Select CLEAR INFO. Road test the vehicle. The input shaft speed must be greater than 550 RPM without a speed change greater than 500 RPM for 2 seconds. 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 harness for poor connections at ISS, transaxle in-line 20-way connector and PCM. Check for bent, backed out or damaged terminals, or for poor terminal tension. Check for chafed wiring. When diagnosing an intermittent condition, wiggle wiring harness while observing scan tool for change in value. Inspect transaxle in-line 20-way connector for transaxle fluid.

DTC P0717: INPUT SPEED SENSOR CIRCUIT (NO SIGNAL)

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

The Input Speed Sensor (ISS) is a permanent magnet generator. The ISS mounts in the transaxle case facing the drive sprocket of the input shaft. As the drive sprocket rotates, an AC voltage is induced and transmitted to the PCM. The PCM converts the AC voltage into a digital signal. The PCM uses the ISS signal to determine shift timing, torque converter clutch slip speed and gear ratio.

If the PCM detects a low input speed while the vehicle and engine speeds are high, then DTC P0717 sets. DTC P0717 is a type "B" DTC.

Conditions For Running DTC P0717

DTC will run under the following conditions

1. No VSS DTCs P0502 or P0503.
2. No internal mode switch DTCs P1820, P1822, P1823, or P1825.
3. The system voltage is 8-18 volts.
4. The engine run time is greater than 5 seconds.
5. The transaxle is not in Park or Neutral.
6. The vehicle speed is 10 MPH or greater.

Conditions For Setting DTC P0717

DTC will set under the following conditions

1. The input shaft speed is 50 RPM or less for 6 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM inhibits TCC engagement.
4. The PCM calculates input shaft speed from vehicle speed and commanded gear.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
6. The PCM stores DTC P0717 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0717

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step tests the ISS for correct resistance.
2. 8 This step tests the ISS high signal circuit for being shorted to another circuit within the transaxle.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Start the engine. Select ISS on the scan tool. Is the input shaft speed greater than 500 RPM? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install the Jumper Harness (J-44152) on the transaxle side of the transaxle in-line 20-way connector. Using a DVOM and Terminal Test Kit (J-35616-A), measure the resistance between jumper harness terminals "S" and "V". Is the resistance 1300-1950 ohms? If so, go to step 7 . If not, go to next step.
4. Is the resistance greater than 1950 ohms? If so, go to next step. If not, go to step 6 .
5. Test the ISS high (1230) and low (1231) signal circuits for high resistance or an open between the transaxle in-line 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 (1230) and low (1231) signal circuits for being shorted together between the transaxle in-line 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 the 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 (1230) for high resistance, an open, a short to ground or a short to voltage between the PCM connector C1 and the transaxle in-line 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 (1231) for high resistance or an open between the PCM connector C1 and the transaxle in-line 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 wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 14 .
12. Replace the ISS. See «INPUT SPEED SENSOR»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 14 .
13. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, 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 shaft speed must be greater than 500 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 harness for poor connections at ISS, transaxle in-line 20-way connector and PCM. Check for bent, backed out or damaged terminals, or for poor terminal tension. Check for chafed wiring. When diagnosing an intermittent condition, wiggle wiring harness while observing scan tool for change in value. Inspect transaxle in-line 20-way connector for transaxle fluid.

DTC P0719: TCC BRAKE SWITCH CIRCUIT LOW INPUT (SWITCH STUCK ON)

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

Note. TCC brake switch is also known as the stoplamp switch.

The TCC brake switch is used to indicate the status of the brake pedal, applied or released, to the PCM. The normally closed TCC brake switch supplies an ignition voltage input to the PCM. Applying the brake pedal opens the switch, interrupting voltage to the PCM. Releasing the brake pedal resumes voltage to the PCM. When the PCM senses zero volts at the TCC brake switch input, the PCM de-energizes the TCC solenoid valve.

If the PCM detects an open TCC brake switch (stuck on) during accelerations, then DTC P0719 sets. DTC P0719 is a type "C" DTC.

Conditions For Running DTC P0719

DTC will run under the following conditions

1. No VSS DTCs P0502 or P0503.
2. DTC P0719 has not passed this ignition cycle.

Conditions For Setting DTC P0719

The TCC brake switch input is at zero volts for 15 minutes and the following conditions occur eight times without a status change on the TCC brake input

1. The vehicle speed is less than 5 MPH.
2. The vehicle accelerates to 20 MPH within 2-6 seconds.
3. Then the vehicle speed remains above 20 MPH for 6 seconds.

PCM performs the following if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE ELECTRICAL SYSTEM displays on the driver information center.
3. The PCM disregards the TCC 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.
4. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
5. The PCM stores DTC P0719 in PCM history.

Conditions For Clearing DTC P0719

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. The TCC brake switch input indicates ignition voltage for 2 seconds.
3. A scan tool can clear the DTC.
4. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
5. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 2 Disconnecting the brake switch connector, jumping the circuit, and observing a status change isolates the brake switch as the source of the DTC.
2. 3 If the voltage circuit (1039) shorts to ground, the IGN 1 fuse opens.
3. 5 If the brake switch is properly adjusted, then the brake switch must be replaced.
4. 8 Replace the PCM only after you have completed the preceding diagnostic steps.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Select TCC BRAKE SWITCH on the scan tool. Disconnect the TCC brake switch connector. Install a fused jumper wire between TCC brake switch connector terminals "A" and "B". Did the TCC brake switch status change from OPEN to CLOSED? If so, go to step 5 . If not, go to next step.
3. Remove the IGN 1 fuse. Inspect the fuse for an open. Is the fuse open? If so, go to next step. If not, go to step 6 .
4. Test the TCC brake switch voltage circuit (1039) for a short to ground. Did you find and correct the condition? If so, go to step 9 .
5. Inspect the TCC brake switch for proper adjustment. Adjust the TCC brake switch as necessary. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Did the TCC brake switch require adjustment? If so, go to step 9 . If not, go to step 7 .
6. Test the TCC brake switch voltage circuit (1039) for an open. Test the TCC brake switch signal circuit (420) for an open. Did you find and correct a condition? If so, go to step 9 . If not, go to step 8 .
7. Replace the TCC brake switch. See «STOPLAMP SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 9 .
8. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, 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 signal 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 .

Inspect wiring for poor connections. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value. Check TCC brake switch for proper adjustment. Check PCM calibration for a current update.

DTC P0724: TCC BRAKE SWITCH CIRCUIT HIGH INPUT (SWITCH STUCK OFF)

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

Note. TCC brake switch is also known as the stoplamp switch.

The TCC brake switch is used to indicate the status of the brake pedal, applied or released, to the PCM. The normally closed TCC brake switch supplies an ignition voltage input to the PCM. Applying the brake pedal opens the switch, interrupting voltage to the PCM. Releasing the brake pedal resumes voltage to the PCM. When the PCM senses zero volts at the TCC brake switch input, the PCM de-energizes the TCC solenoid valve.

If the PCM detects a closed TCC brake switch (stuck off) during decelerations, then DTC P0724 sets. DTC P0724 is a type "C" DTC.

Conditions For Running DTC P0724

DTC will run under the following conditions

1. No VSS DTCs P0502 or P0503.
2. DTC P0724 has not passed this ignition cycle.

Conditions For Setting DTC P0724

DTC will set when the TCC brake switch input indicates ignition volts and the following conditions occur eight times without a status change on the TCC brake input

1. Vehicle speed is greater than 20 MPH for 6 seconds.
2. The vehicle speed decreases to 5 MPH within 2-6 seconds.
3. Then vehicle speed is less than 5 MPH.

PCM performs the following if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE ELECTRICAL SYSTEM displays on the driver information center.
3. The PCM turns off the Brake Transmission Shift Interlock (BTSI) solenoid.
4. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
5. The PCM stores DTC P0724 in PCM history.

Conditions For Clearing DTC P0724

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. The TCC brake switch input indicates zero volts for 2 seconds.
3. A scan tool can clear the DTC.
4. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
5. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 2 Disconnecting the brake switch connector, and observing a status change, isolates the brake switch as the source of the DTC.
2. 3 This step inspects the signal circuit for a short to voltage if the brake switch status on the scan tool did not change in step 2) .
3. 4 If the brake switch is properly adjusted, then the brake switch must be replaced.
4. 5 Replace the PCM only after you have completed the preceding diagnostic steps.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Select TCC BRAKE SWITCH on the scan tool. Disconnect the TCC brake switch connector. Does the TCC brake switch status change from CLOSED to OPEN? If so, go to step 4 . If not, go to next step.
3. Test the TCC brake switch signal circuit (420) for a short to voltage. Did you find and correct the condition? If so, go to step 6 . If not, go to step 5 .
4. Replace the TCC brake switch. See «STOPLAMP SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 6 .
5. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, 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 2 seconds. Select SPECIFIC DTC. Enter DTC P0724. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value. Check TCC brake switch for proper adjustment. Check PCM calibration for a current update.

DTC P0731: INCORRECT 1ST GEAR RATIO

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

The PCM calculates gear ratio based on data from the input and output speed sensors. The PCM compares the known gear ratio to a calculated ratio for each commanded gear.

If the PCM detects an incorrect 1st gear ratio, indicating excessive slip or drag within the transaxle, then DTC P0731 sets. DTC P0731 is a type "C" DTC.

Conditions For Running DTC P0731

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 internal mode switch DTCs P1820, P1822, P1823, or P1825.
5. The engine run time is greater than 5 seconds.
6. The transaxle is not in Park or Neutral.
7. The time since the gearshift lever change is greater than 6 seconds.
8. The transmission fluid temperature is 68-271°F (20-133°C).
9. The throttle angle is 10 percent or greater.
10. The vehicle speed is 3 MPH or greater.
11. The engine torque is 30-100 ft. lbs. (40-135 N.m).

Conditions For Setting DTC P0731

DTC sets when the PCM commands 1st gear and one of the following conditions occurs for 0.75 second

1. The gear ratio is greater than 3.11:1.
2. The gear ratio is 2.23:1 to 2.87:1.
3. The gear ratio is 1.71:1 to 2.02:1.
4. The gear ratio is 1.05:1 to 1.54:1.
5. The gear ratio is 0.71:1 to 0.95:1.
6. The gear ratio is less than 0.65:1.

PCM performs the following actions if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE TRANSMISSION displays on the driver information center.
3. The PCM commands maximum line pressure.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
6. The PCM stores DTC P0731 in PCM history.

Conditions For Clearing DTC P0731

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. The PCM commands 1st gear and detects a correct 1st gear ratio for one second.
3. A scan tool can clear the DTC.
4. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
5. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 3 This step tests for low fluid level, which may cause slipping, and result in an incorrect gear ratio.
2. 4 This step verifies that the correct 1st gear ratio occurs for commanded 1st gear.
3. 5 This step tests for low line pressure.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Visually inspect the transaxle cooling system for fluid leaks. Did you find the condition? If so, go to step 8 . If not, go to next step.
3. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
4. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D1" and record the 1st gear ratio. Is the 1st gear ratio 2.87:1-3.11:1? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
5. Perform the line pressure check procedure. See «HYDRAULIC PRESSURE TESTS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__hydraulic-pressure-tests) under PERFORMANCE TESTS. Is the line pressure within specifications? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
6. Inspect the forward clutch assembly for: Snap ring out of position or damaged. Clutch plates slipping, dragging or damaged. Apply ring seized or damaged. Piston cracked or damaged. Piston seals rolled, worn or damaged. Release spring assembly damaged. Housing checkball blocked by debris or damaged. The forward sprag clutch not holding or damaged. Inspect the low-reverse servo assembly for: Piston cracked or damaged. Piston seals rolled, worn or damaged. Apply pin seized or damaged. Piston return spring or cushion spring damaged. The low-reverse band slipping, dragging, or damaged. The low-roller clutch not holding or damaged. Repair any of the above items as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
7. Change the transmission fluid and filter. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Use the scan tool to reset oil life monitor to 100 percent and clear TAPS. Did you complete the procedures? If so, go to next step.
8. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle. The transmission fluid temperature is 68-271°F (20-133°C). The engine torque is 30-100 ft. lbs. (40-135 N.m). Drive the vehicle in "D4" with the throttle angle greater than 10 percent to obtain a correct 1st gear ratio for 1 second. Select SPECIFIC DTC. Enter DTC P0731. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect for the following items

1. Inspect for intermittent conditions in the ISS and OSS circuits.
2. Ask the customer about possible overloading, exceeding the trailer towing limit, or towing in Overdrive.
3. Ensure that the current calibration is correct for the final drive ratio.

DTC P0732: INCORRECT 2ND GEAR RATIO

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

The PCM calculates gear ratio based on data from the input and output speed sensors. The PCM compares the known gear ratio to a calculated ratio for each commanded gear.

If the PCM detects an incorrect 2nd gear ratio, indicating excessive slip or drag within the transmission, then DTC P0732 sets. DTC P0732 is a type "C" DTC.

Conditions For Running DTC P0732

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 internal mode switch DTCs P1820, P1822, P1823, or P1825.
5. The engine run time is greater than 5 seconds.
6. The transaxle is not in Park or Neutral.
7. The time since the gearshift lever change is greater than 6 seconds.
8. The transmission fluid temperature is 68-271°F (20-133°C).
9. The throttle angle is 10 percent or greater.
10. The vehicle speed is 3 MPH or greater.
11. The engine torque is 30-100 ft. lbs. (40-135 N.m).

Conditions For Setting DTC P0732

DTC sets when the PCM commands 2nd gear and one of the following conditions occurs for one second

1. The gear ratio is greater than 3.11:1.
2. The gear ratio is 2.23:1 to 2.87:1.
3. The gear ratio is 1.71:1 to 2.02:1.
4. The gear ratio is 1.05:1 to 1.54:1.
5. The gear ratio is 0.71:1 to 0.95:1.
6. The gear ratio is less than 0.65:1.

PCM performs the following actions if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE TRANSMISSION displays on the driver information center.
3. The PCM commands maximum line pressure.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
6. The PCM stores DTC P0732 in PCM history.

Conditions For Clearing DTC P0732

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. The PCM commands 2nd gear and detects a correct 2nd gear ratio for one second.
3. A scan tool can clear the DTC.
4. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
5. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 3 This step tests for low fluid level, which may cause slipping, and result in an incorrect gear ratio.
2. 4 This step verifies that the correct 2nd gear ratio occurs for commanded 2nd gear.
3. 5 This step tests for low line pressure.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Visually inspect the transaxle cooling system for fluid leaks. Repair leaks as necessary. Did you find and correct a condition? If so, go to step 8 . If not, go to next step.
3. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
4. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D2" and record the 2nd gear ratio. Is the 2nd gear ratio 1.54:1-1.71:1? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
5. Perform the line pressure check procedure. See «HYDRAULIC PRESSURE TESTS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__hydraulic-pressure-tests) under PERFORMANCE TESTS. Is the line pressure within specifications? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
6. Inspect the forward clutch assembly for: Snap ring out of position or damaged. Clutch plates slipping, dragging or damaged. Apply ring seized or damaged. Piston cracked or damaged. Piston seals rolled, worn or damaged. Release spring assembly damaged. Housing checkball blocked by debris or damaged. The forward sprag clutch not holding or damaged. Inspect the 2nd clutch assembly for: Piston cracked or damaged. Piston seals rolled, worn or damaged. Clutch plates slipping, dragging or damaged. Return spring and retainer assembly damaged. Air bleed checkball blocked by debris or damaged. The 2nd sprag clutch not holding or damaged. Repair any of the above items as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
7. Change the transmission fluid and filter. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Use the scan tool to reset oil life monitor to 100 percent and clear TAPS. Did you complete the procedures? If so, go to next step.
8. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle. The transmission fluid temperature is 68-271°F (20-133°C). The engine torque is 30-100 ft. lbs. (40-135 N.m). Drive the vehicle in "D4" with the throttle angle greater than 10 percent to obtain a correct 2nd gear ratio for one second. Select SPECIFIC DTC. Enter DTC P0732. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Ask the customer about overloading the vehicle, exceeding the trailer-towing limit, or towing in Overdrive. Inspect for intermittent input or output shaft speed sensor circuit conditions. Ensure that the current calibration is correct for the final drive ratio.

DTC P0733: INCORRECT 3RD GEAR RATIO

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

The PCM calculates gear ratio based on data from the input and output speed sensors. The PCM compares the known gear ratio to a calculated ratio for each commanded gear.

If the PCM detects an incorrect 3rd gear ratio, indicating excessive slip or drag within the transaxle, then DTC P0733 sets. DTC P0733 is a type "C" DTC.

Conditions For Running DTC P0733

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 internal mode switch DTCs P1820, P1822, P1823, or P1825.
5. The engine run time is greater than 5 seconds.
6. The transaxle is not in Park or Neutral.
7. The time since the gearshift lever change is greater than 6 seconds.
8. The transmission fluid temperature is 68-271°F (20-133°C).
9. The throttle angle is 10 percent or greater.
10. The vehicle speed is 3 MPH or greater.
11. The engine torque is 30-100 ft. lbs. (40-135 N.m).

Conditions For Setting DTC P0733

DTC sets when the PCM commands 3rd gear and one of the following conditions occurs for 4 seconds

1. The gear ratio is greater than 3.11:1.
2. The gear ratio is 2.23:1 to 2.87:1.
3. The gear ratio is 1.71:1 to 2.02:1.
4. The gear ratio is 1.05:1 to 1.54:1.
5. The gear ratio is 0.71:1 to 0.95:1.
6. The gear ratio is less than 0.65:1.

PCM performs the following actions if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE TRANSMISSION displays on the driver information center.
3. The PCM commands maximum line pressure.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
6. The PCM stores DTC P0733 in PCM history.

Conditions For Clearing DTC P0733

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. The PCM commands 3rd gear and detects a correct 3rd gear ratio for one second.
3. A scan tool can clear the DTC.
4. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
5. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 3 This step tests for low fluid level, which may cause slipping, and result in an incorrect gear ratio.
2. 4 This step verifies that the correct 3rd gear ratio occurs for commanded 3rd gear.
3. 5 This step tests for low line pressure.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Visually inspect the transaxle cooling system for fluid leaks. Repair leaks as necessary. Did you find and correct a condition? If so, go to step 8 . If not, go to next step.
3. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
4. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D3" and record the 3rd gear ratio. Is the 3rd gear ratio 0.95:1-1.05:1? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
5. Perform the line pressure check procedure. See «HYDRAULIC PRESSURE TESTS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__hydraulic-pressure-tests) under PERFORMANCE TESTS. Is the line pressure within specifications? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
6. Inspect the forward clutch assembly for: Snap ring out of position or damaged. Clutch plates slipping, dragging or damaged. Apply ring seized or damaged. Piston cracked or damaged. Piston seals rolled, worn or damaged. Release spring assembly damaged. Housing checkball blocked by debris or damaged. The forward sprag clutch not holding or damaged. Inspect the 2nd clutch assembly for: Piston cracked or damaged. Piston seals rolled, worn or damaged. Clutch plates slipping, dragging or damaged. Return spring and retainer assembly damaged. Air bleed checkball blocked by debris or damaged. Inspect the 3rd clutch assembly for: Snap ring out of position or damaged. Clutch plates slipping, dragging or damaged. Return spring and retainer assembly damaged. Piston cracked or damaged. Piston seals rolled, worn or damaged. Piston checkballs blocked by debris or damaged. Repair any of the above items as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
7. Change the transmission fluid and filter. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Use the scan tool to reset oil life monitor to 100 percent and clear TAPS. Did you complete the procedures? If so, go to next step.
8. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle The transmission fluid temperature is 68-271°F (20-133°C). The engine torque is 30-100 ft. lbs. (40-135 N.m). Drive the vehicle in "D4" with the throttle angle greater than 10 percent to obtain a correct 3rd gear ratio for one second. Select SPECIFIC DTC. Enter DTC P0733. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect for the following items

1. Ask the customer about overloading the vehicle, exceeding the trailer-towing limit, or towing in Overdrive.
2. Inspect for intermittent input and output speed sensor circuit conditions.
3. Ensure that the current calibration is correct for the final drive ratio.

DTC P0734: INCORRECT 4TH GEAR RATIO

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

The PCM calculates gear ratio based on data from the input and output speed sensors. The PCM compares the known gear ratio to a calculated ratio for each commanded gear.

If the PCM detects an incorrect 4th gear ratio, indicating excessive slip or drag within the transaxle, then DTC P0734 sets. DTC P0734 is a type "C" DTC.

Conditions For Running DTC P0734

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 internal mode switch DTCs P1820, P1822, P1823, or P1825.
5. The engine run time is greater than 5 seconds.
6. The transaxle is not in Park or Neutral.
7. The time since the gearshift lever change is greater than 6 seconds.
8. The transmission fluid temperature is 68-271°F (20-133°C).
9. The throttle angle is 10 percent or greater.
10. The vehicle speed is 3 MPH or greater.
11. The engine torque is 30-100 ft. lbs. (40-135 N.m).

Conditions For Setting DTC P0734

DTC sets when the PCM commands 4th gear and one of the following conditions occurs for 4 seconds

1. The gear ratio is greater than 3.11:1.
2. The gear ratio is 2.23:1 to 2.87:1.
3. The gear ratio is 1.71:1 to 2.02:1.
4. The gear ratio is 1.05:1 to 1.54:1.
5. The gear ratio is 0.71:1 to 0.95:1.
6. The gear ratio is less than 0.65:1.

PCM performs the following actions if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE TRANSMISSION displays on the driver information center.
3. The PCM commands maximum line pressure.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
6. The PCM stores DTC P0734 in PCM history.

Conditions For Clearing DTC P0734

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. The PCM commands 4th gear and detects a correct 4th gear ratio for one second.
3. A scan tool can clear the DTC.
4. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
5. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 3 This step tests for low fluid level, which may cause slipping, and result in an incorrect gear ratio.
2. 4 This step verifies that the correct 4th gear ratio occurs for commanded 4th gear.
3. 5 This step tests for low line pressure.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Visually inspect the transaxle cooling system for fluid leaks. Repair leaks as necessary. Did you find and correct a condition? If so, go to step 8 . If not, go to next step.
3. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
4. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D4" and record the 4th gear ratio. Is the 4th gear ratio 0.65:1-0.71:1? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
5. Perform the line pressure check procedure. See «HYDRAULIC PRESSURE TESTS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__hydraulic-pressure-tests) under PERFORMANCE TESTS. Is the line pressure within specifications? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
6. Inspect the forward clutch assembly for: Snap ring out of position or damaged. Clutch plates slipping, dragging or damaged. Apply ring seized or damaged. Piston cracked or damaged. Piston seals rolled, worn or damaged. Release spring assembly damaged. Housing checkball blocked by debris or damaged. Inspect the 2nd clutch assembly for: Piston cracked or damaged. Piston seals rolled, worn or damaged. Clutch plates slipping, dragging or damaged. Return spring and retainer assembly damaged. Air bleed checkball blocked by debris or damaged. Inspect the 3rd clutch assembly for: Snap ring out of position or damaged. Clutch plates slipping, dragging or damaged. Return spring and retainer assembly damaged. Piston cracked or damaged. Piston seals rolled, worn or damaged. Piston checkballs blocked by debris or damaged. Inspect the 4th servo assembly for: Servo cover cracked or damaged. Servo cover seal rolled, worn or damaged. Piston cracked or damaged. Piston seal rolled, worn or damaged. Spring and retainer assembly damaged. Servo pin seized or damaged. The 4th band slipping, dragging or damaged. The 4th band anchor pin out of position or damaged. Repair any of the above items as necessary. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
7. Change the transmission fluid and filter. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Use the scan tool to reset oil life monitor to 100 percent and clear TAPS. Did you complete the procedures? If so, go to next step.
8. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle. The transmission fluid temperature is 68-271°F (20-133°C). The engine torque is 30-100 ft. lbs. (40-135 N.m). Drive the vehicle in "D4" with the throttle angle greater than 10 percent to obtain a correct 4th gear ratio for one second. Select SPECIFIC DTC. Enter DTC P0734. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect for the following items

1. Ask the customer about overloading the vehicle, exceeding the trailer-towing limit, or towing in Overdrive.
2. Inspect for intermittent input or output speed sensor circuit conditions.
3. Ensure that the current calibration is correct for the final drive ratio.

DTC P0741: TCC SYSTEM STUCK OFF

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

The PCM controls the Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid valve. The solenoid controls the hydraulic fluid for TCC apply and release. When the TCC is applied, the engine is coupled directly to the transaxle through the TCC. The TCC slip speed should be near zero.

If the PCM detects high torque converter slip when the TCC is commanded on, then DTC P0741 sets. DTC P0741 is a type "B" DTC.

Conditions For Running DTC P0741

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 TCC stuck on DTC P0742.
5. No internal mode switch DTCs P1820, P1822, P1823 or P1825.
6. No TCC PWM solenoid valve DTC P1860.
7. The engine run time is greater than 5 seconds.
8. The time since the gearshift lever change is greater than 6 seconds.
9. The internal mode switch indicates "D2", "D3" or "D4".
10. The transaxle gear ratio indicates 2nd, 3rd or 4th gear.
11. The transmission fluid temperature is 68-271°F (20-133°C).
12. The throttle angle is 10-50 percent.
13. The engine torque is 32-159 ft. lbs. (43-215 N.m).
14. The TCC solenoid valve is commanded on.

Conditions For Setting DTC P0741

DTC will set under the following condition

1. TCC slip speed exceeds its limit for a given torque for 5 seconds. See «TCC SLIP SPECIFICATIONS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) table.

TCC SLIP SPECIFICATIONS

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM inhibits 4th gear if the transaxle is in hot mode.
3. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
4. The PCM stores DTC P0741 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0741

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 2 This step inspects the transmission fluid to ensure that it is at the proper level.
2. 3 This step verifies that the TCC engages when commanded on by the scan tool.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. 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 -20 to 100 RPM? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
4. Inspect for the following conditions: The TCC control valve is stuck off due to sediment or binding. The TCC regulator valve is stuck off due to sediment or binding. The TCC feed valve is stuck off due to sediment or binding. The oil pressure screen is clogged. The TCC PWM solenoid valve "O" ring is leaking or cut. The turbine shaft seals are worn or cut. Repair any of the above items 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. Operate the vehicle. The transmission fluid temperature is 68-271°F (20-133°C). The engine torque is 32-159 ft. lbs. (43-215 N.m). Drive the vehicle in "D4" with a throttle angle of 10-50 percent. Ensure that the TCC applies and the slip speed is -20 to 100 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 the transmission fluid level. The transaxle may be in hot mode. Inspect the transmission fluid lines to the radiator. The lines may be pinched, plugged or twisted.

DTC P0742: TCC SYSTEM STUCK ON

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

The PCM controls the Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid valve. The solenoid controls the hydraulic fluid for TCC apply and release. When the vehicle is accelerating, the PCM commands the TCC to be disengaged.

If the PCM detects a TCC slip from -20 to 150 RPM, when the TCC is commanded off, then DTC P0742 sets. DTC P0742 is a type "B" DTC.

Conditions For Running DTC P0742

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 TCC stuck off DTC P0741.
5. No internal mode switch DTCs P1820, P1822, P1823, or P1825.
6. No TCC PWM solenoid valve DTC P1860.
7. The engine run time is greater than 5 seconds.
8. The internal mode switch indicates "D4".
9. The transaxle gear ratio indicates 3rd or 4th gear.
10. The transmission fluid temperature is 68-271°F (20-133°C).
11. The throttle angle is 20-90 percent.
12. The engine torque is 114-217 ft. lbs. (155-294 N.m).
13. The vehicle speed is 10-80 MPH.
14. The TCC is commanded off.

Conditions For Setting DTC P0742

DTC will set under the following conditions

1. The TCC slip speed is -20 to 150 RPM for 4.5 seconds, twice during the same trip.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM inhibits TCC engagement.
3. The PCM freezes shift adapt functions.
4. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
5. The PCM stores DTC P0742 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0742

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 2 This step verifies that the PCM commands the TCC PWM solenoid valve off and the slip speed is -20 to 150 RPM.
2. 3 This step inspects and repairs the components that caused the DTC to set.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Select TCC DUTY CYCLE and TCC SLIP SPEED on the scan tool. Drive the vehicle in "D4" While in 4th gear, command a throttle angle greater than 20 percent. While the TCC duty cycle is zero percent, does the scan tool display a TCC slip speed within -20 to 150 RPM? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
3. Inspect for the following conditions: The TCC PWM solenoid valve is stuck on due to sediment. The TCC converter feed limit valve is stuck on due to sediment. Repair or replace any malfunctioning component. See appropriate OVERHAUL article. Did you complete the repair? If so, go to next step.
4. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Operate the vehicle Drive the vehicle in "D4" with a throttle angle of 20-90 percent and a vehicle speed greater than 10 MPH. The transmission fluid temperature is 68-271°F (20-133°C). The engine torque is 114-217 ft. lbs. (155-294 N.m). The TCC slip speed must be 175-1500 RPM for 5 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 may set DTC P0742. The customer may notice an engine stalling condition.

DTC P0748: PRESSURE CONTROL SOLENOID CIRCUIT ELECTRICAL MALFUNCTION

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

The Pressure Control (PC) solenoid valve regulates actuator feed fluid passing through the solenoid into torque signal pressure. The PCM uses a pulse width modulated signal to control the torque signal pressure. The PCM compares various inputs to determine the appropriate pressure for a given load. The PCM varies the current to the PC solenoid valve from 0.1 amp (for maximum line pressure) to 1.1 amps (for minimum line pressure). An internal current monitor within the PCM provides feedback to determine actual PC solenoid valve current draw.

If the PCM detects a continuous open, short to ground or short to voltage in the PC solenoid valve circuit, then DTC P0748 sets. DTC P0748 is a type "C" DTC.

Conditions For Running DTC P0748

DTC will run under the following conditions

1. The system voltage is at least 10.7 volts.
2. The engine speed is 400 RPM or greater.

Conditions For Setting DTC P0748

DTC will set under the following condition

1. The PC solenoid valve feedback circuit indicates a continuous open, short to ground or short to voltage for greater than 0.1 second.

PCM performs the following if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE TRANSMISSION displays on the driver information center.
3. The PCM commands maximum line pressure.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
6. The PCM stores DTC P0748 in PCM history.

Conditions For Clearing DTC P0748

DTC will clear under the following conditions

1. The PCM clears the DIC when the condition no longer exists.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 2 This step verifies the ability of the PCM to command the PC solenoid valve.
2. 3 This step verifies that the transaxle wiring harness and the PC solenoid valve have correct resistance.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Start the engine. Using the scan tool, increase and decrease the PC solenoid valve amperage. Observe the scan tool display. Does the PC SOL ACTUAL CURRENT vary from the PC SOL REF CURRENT by more than 0.05 amp? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the transaxle side of the transaxle in-line 20-way connector. Using a DVOM and Terminal Test Kit (J-35616-A), measure the resistance between jumper harness terminals "C" and "D". Is the resistance 3-8 ohms? If so, go to step 7 . If not, go to next step.
4. Is the resistance greater than 8 ohms? If so, go to next step. If not, go to step 6 .
5. Test the PC solenoid valve high control circuit (1228) for an open between the transaxle in-line 20-way connector and the PC solenoid valve. Test the PC solenoid valve low control circuit (1229) for an open between the transaxle in-line 20-way connector and the PC solenoid valve. Did you find a condition? If so, go to step 18 . If not, go to step 19 .
6. Test the PC solenoid valve high (1228) and low (1229) control circuits for being shorted together between the transaxle in-line 20-way connector and the PC solenoid valve. Did you find the 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 10 ohms? If so, go to next step. If not, go to step 9 .
8. Test the PC solenoid valve high control circuit (1228) for a short to ground between the transaxle in-line 20-way connector and the PC solenoid valve. Test the PC solenoid valve low control circuit (1229) for a short to ground between the transaxle in-line 20-way connector and the PC solenoid valve. 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 100 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 in-line 20-way connector. Install the jumper harness on the engine side of the transaxle in-line 20-way connector. Disconnect PCM connector C1. 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 valve low control circuit (1229) for a short to ground between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 21 .
12. Measure the resistance between PCM connector C1 terminal No. 67 and jumper harness terminal "D". Is the resistance less than 10 ohms? If so, go to step 14 . If not, go to next step.
13. Test the PC solenoid valve low control circuit (1229) for an open between the PCM connector C1 and the transaxle in-line 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 valve high control circuit (1228) for a short to ground between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 21 .
16. Measure the resistance between PCM connector C1 terminal No. 69 and jumper harness terminal "C". Is the resistance less than 10 ohms? If so, go to step 20 . If not, go to next step.
17. Test the PC solenoid valve high control circuit (1228) for an open between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 21 .
18. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 21 .
19. Replace the PC solenoid valve. See «PRESSURE CONTROL SOLENOID VALVE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 21 .
20. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
21. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Start and idle the engine. System voltage must be at least 10.7 volts. 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, transaxle in-line 20-way connector and pressure control solenoid. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. Check for moisture and corrosion in wiring and connections. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

DTC P0751: 1-2 SHIFT SOLENOID VALVE PERFORMANCE

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 4 different shifting combinations. The 1-2 shift solenoid valve is attached to the lower 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 1-2 shift solenoid valve is stuck off or if 1-2 shift valve is stuck off.

If the PCM detects a 2-2-3-3 shift pattern, then DTC P0751 sets. DTC P0751 is a type "B" DTC.

Conditions For Running DTC P0751

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 internal mode switch DTCs P1820, P1822, P1823 or P1825.
5. No shift solenoid electrical DTCs P1842, P1843, P1845 or P1847.
6. The engine run time is greater than 5 seconds.
7. The internal mode switch indicates "D1", "D2", "D3" or "D4".
8. The transmission fluid temperature is 68-271°F (20-133°C).
9. The throttle angle is 7.5 percent or greater.
10. The vehicle speed is 5 MPH or greater.
11. The engine torque is 59-291 ft. lbs. (80-395 N.m).

Conditions For Setting DTC P0751

DTC will set if the following conditions occur twice during the same trip

1. The PCM commands 1st gear and the gear ratio is 1.54:1-1.71:1 (2nd gear) for 1.5 seconds.
2. The PCM commands 4th gear and the gear ratio is 0.95:1-1.05:1 (3rd gear) for 4 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM inhibits TCC engagement.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
6. The PCM stores DTC P0751 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0751

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.

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

1. 3 This step verifies a 2-2-3-3 shift pattern.
2. 4 This step tests for a mechanical or hydraulic condition causing the 1-2 shift solenoid valve to be stuck off, or the circuit to be released.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D4" to obtain 1-2, 2-3 and 3-4 shifts with a throttle angle of 7.5 percent or greater. With the scan tool, observe current (commanded) gear and gear ratio for each gear. Standard values are: 1st: 2.87:1 to 3.11:1 2nd: 1.54:1 to 1.71:1 3rd: 0.95:1 to 1.05:1 4th: 0.65:1 to 0.71:1 Did the gear ratios indicate a 2-2-3-3 shift pattern? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
4. Inspect the 1-2 shift circuit for the following conditions: 1-2 shift solenoid valve mechanically stuck off. See «SHIFT SOLENOID LEAK TEST»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-leak-test) under COMPONENT TESTS. 1-2 shift solenoid valve "O" ring worn or damaged. 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 in "D4" with a throttle angle of 7.5 percent or greater. Allow the transaxle to shift through all the gears. Monitor the commanded gear and gear ratios. The actual gear ratios must match the commanded gears for 0.75 seconds, 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 .

If DTC P0751 is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist

1. Fluid Contamination
2. Plugged Fluid Circuits
3. Restricted Fluid Circuits

DTC P0752: 1-2 SHIFT SOLENOID VALVE PERFORMANCE

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 4 different shifting combinations. The 1-2 shift solenoid valve is attached to the lower 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 P0752 sets if 1-2 shift solenoid stuck on or 1-2 shift valve stuck on.

If the PCM detects a 1-1-4-4 shift pattern, then DTC P0752 sets. DTC P0752 is a type "B" DTC.

Conditions For Running DTC P0752

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 internal mode switch DTCs P1820, P1822, P1823 or P1825.
5. No shift solenoid electrical DTCs P1842, P1843, P1845 or P1847.
6. The engine run time is greater than 5 seconds.
7. The internal mode switch indicates "D1", "D2", "D3" or "D4".
8. The transmission fluid temperature is 68-271°F (20-133°C).
9. The throttle angle is 7.5 percent or greater.
10. The vehicle speed is 5 MPH or greater.
11. The engine torque is 59-291 ft. lbs. (80-395 N.m).

Conditions For Setting DTC P0752

DTC will set if the following conditions both occur twice in one trip

1. The PCM commands 2nd gear and the gear ratio is 2:87:1-3.11:1 (1st gear) for 2 seconds.
2. The PCM commands 3rd gear and the gear ratio is 0.65:1-0.71:1 (4th gear) for 4 seconds.

PCM performs the following actions if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM inhibits TCC engagement.
4. The PCM inhibits 3-2 downshifts above 31 MPH.
5. The PCM freezes shift adapt functions.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P0752 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P0752

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.

The number listed below refers to step number in the diagnostic procedure

1. 3 This step verifies a 1-1-4-4 shift pattern.
2. 4 This step tests for a mechanical or hydraulic condition causing the 1-2 shift solenoid valve to be stuck on, or the circuit to be applied.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D4" to obtain 1-2, 2-3 and 3-4 shifts with a throttle angle of 7.5 percent or greater. With the scan tool, observe current (commanded) gear and gear ratio for each gear. Standard values are: 1st: 2.87:1 to 3.11:1 2nd: 1.54:1 to 1.71:1 3rd: 0.95:1 to 1.05:1 4th: 0.65:1 to 0.71:1 Did the gear ratios indicate a 1-1-4-4 shift pattern? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
4. Inspect the 1-2 shift circuit for the following conditions: 1-2 shift solenoid valve mechanically stuck on. See «SHIFT SOLENOID LEAK TEST»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-leak-test) under COMPONENT TESTS. 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 in "D4" with a throttle angle of 7.5 percent or greater. Allow the transaxle to shift through all the gears. Monitor the commanded 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 is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist

1. Fluid Contamination
2. Plugged Fluid Circuits
3. Restricted Fluid Circuits

DTC P0756: 2-3 SHIFT SOLENOID VALVE PERFORMANCE

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. The 2-3 shift solenoid valve is attached to the lower 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 if 2-3 shift solenoid valve is stuck on or 2-3 shift valve is stuck on.

If the PCM detects a 4-3-3-4 shift pattern, then DTC P0756 sets. DTC P0756 is a type "A" DTC.

Conditions For Running DTC P0756

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 internal mode switch DTCs P1820, P1822, P1823 or P1825.
5. No shift solenoid electrical DTCs P1842, P1843, P1845 or P1847.
6. The engine run time is greater than 5 seconds.
7. The internal mode switch indicates "D1", "D2", "D3" or "D4".
8. The transmission fluid temperature is 68-271°F (20-133°C).
9. The throttle angle is 10 percent or greater.
10. The vehicle speed is 5 MPH or greater.
11. The engine torque is 59-291 ft. lbs. (80-395 N.m).

Conditions For Setting DTC P0756

DTC will set if following conditions both occur twice in one trip

1. The PCM commands 1st gear and the gear ratio is 0.65:1-0.71:1 (4th gear) for one second.
2. The PCM commands 2nd gear and the gear ratio is 0.95:1-1.05:1 (3rd gear) for 0.5 second.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL.
2. The PCM commands an immediate landing to 2nd gear.
3. The PCM commands maximum line pressure.
4. The PCM inhibits TCC engagement.
5. The PCM freezes shift adapt functions.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P0756 in PCM history.

Conditions For Clearing DTC P0756

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.

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

1. 3 This step verifies a 4-3-3-4 shift pattern.
2. 4 This step tests for a mechanical or hydraulic condition causing the 2-3 shift solenoid valve to be stuck on, or the circuit to be applied.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D4" to obtain 1-2, 2-3 and 3-4 shifts with a throttle angle of 10 percent or greater. With the scan tool, observe current (commanded) gear and gear ratio for each gear. Standard values are: 1st: 2.87:1 to 3.11:1 2nd: 1.54:1 to 1.71:1 3rd: 0.95:1 to 1.05:1 4th: 0.65:1 to 0.71:1 Did the gear ratios indicate a 4-3-3-4 shift pattern? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
4. Inspect the 2-3 shift circuit for the following conditions: 2-3 shift solenoid valve mechanically stuck on. See «SHIFT SOLENOID LEAK TEST»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-leak-test) under COMPONENT TESTS. 2-3 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 in "D4" with a throttle angle of 10 percent or greater. Allow the transaxle to shift through all the gears. Monitor the commanded 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 .

It is possible to have a 2nd or 3rd gear ratio depending on the type of malfunction. If DTC P0756 is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist

1. Fluid contamination.
2. Plugged fluid circuits.
3. Restricted fluid circuits.

DTC P0757: 2-3 SHIFT SOLENOID VALVE PERFORMANCE

Note. For circuit identification, see CONNECTOR IDENTIFICATION and 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. The 2-3 shift solenoid valve is attached to the lower 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 if 2-3 shift solenoid valve is stuck off or 2-3 shift valve is stuck off.

If the PCM detects a 1-2-2-1 shift pattern, then DTC P0757 sets. DTC P0757 is a type "A" DTC.

Conditions For Running DTC P0757

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 internal mode switch DTCs P1820, P1822, P1823 or P1825.
5. No shift solenoid electrical DTCs P1842, P1843, P1845 or P1847.
6. The engine run time is greater than 5 seconds.
7. The internal mode switch indicates "D1", "D2", "D3" or "D4".
8. The transmission fluid temperature is 20-133°C (68-271°F).
9. The throttle angle is 10 percent or greater.
10. The vehicle speed is 5 MPH or greater.
11. The engine torque is 59-291 ft. lbs. (80-395 N.m) during 3rd gear command.
12. The engine torque is 7-291 ft. lbs. (10-395 N.m) during 4th gear command.

Conditions For Setting DTC P0757

DTC will set if following conditions both occur twice in one trip

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 2.87:1-3.11:1 (1st gear) for 2 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL.
2. The PCM commands an immediate landing to 2nd gear.
3. The PCM commands maximum line pressure.
4. The PCM inhibits TCC engagement.
5. The PCM freezes shift adapt functions.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P0757 in PCM history.

Conditions For Clearing DTC P0757

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.

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

1. 3 This step verifies a 1-2-2-1 shift pattern.
2. 4 This step tests for a mechanical or hydraulic condition causing the 2-3 shift solenoid valve to be stuck off, or the circuit to be released.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Use the scan tool snapshot mode to record commanded gear and gear ratio. Drive the vehicle in "D4" to obtain 1-2, 2-3, 3-4 shifts with a throttle angle of 10 percent or greater. With the scan tool, observe current (commanded) gear and gear ratio for each gear. Standard values are: 1st: 2.87:1 to 3.11:1 2nd: 1.54:1 to 1.71:1 3rd: 0.95:1 to 1.05:1 4th: 0.65:1 to 0.71:1 Did the gear ratios indicate a 1-2-2-1 shift pattern? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
4. Inspect the 2-3 shift circuit for the following conditions: 2-3 shift solenoid valve mechanically stuck off. See «SHIFT SOLENOID LEAK TEST»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-leak-test) under COMPONENT TESTS. 2-3 shift solenoid valve "O" ring worn or damaged. 2-3 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 in "D4" with a throttle angle of 10 percent or greater. Engine torque must be 12-291 ft. lbs. (16-395 N.m). Allow the transaxle to shift through all the gears. Monitor the commanded 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 is cleared, then will not reset when the vehicle is driven, some of the following conditions may exist

1. Fluid contamination.
2. Plugged fluid circuits.
3. Restricted fluid circuits.

DTC P1811: MAXIMUM ADAPT & LONG SHIFT

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

An adaptive modifier modifies the line pressure. The adaptive modifier controls the shift execution time. This DTC monitors the time required to accomplish the shift. If the shift takes longer than 0.65 second, and the adaptive modifier cannot shorten this time, then counter repeats.

DTC P1811 sets when this counter reaches its limit. DTC P1811 is a type "C" DTC.

Conditions For Running DTC P1811

DTC will run under the following conditions

1. An adaptable shift has occurred.

Condition No. 1 For Setting DTC P1811

Note. One of the following conditions occurs twice during the same trip.

DTC will set under the following conditions

1. The 1-2 shift is longer than 0.65 second.
2. The 1-2 shift adapt has reached its limit.

Condition No. 2 For Setting DTC P1811

DTC will set under the following conditions

1. The 2-3 shift is longer than 0.65 second.
2. The 2-3 shift adapt has reached its limit.

Condition No. 3 For Setting DTC P1811

DTC will set under the following conditions

1. The 3-4 shift is longer than 0.65 second.
2. The 3-4 shift adapt has reached its limit.

PCM performs the following if DTC is set

1. The PCM does not illuminate the MIL.
2. SERVICE TRANSMISSION displays on the driver information center.
3. The PCM commands maximum line pressure.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
6. The PCM stores DTC P1811 in PCM history.

Conditions For Clearing DTC P1811

DTC will clear under the following conditions

1. The PCM clears the driver information center message when the condition no longer exists.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 3 This step reviews the 1-2 adapt cells. If the pressure readings match or exceed the value listed in the value column, then the PCM modifies the base line pressure on a 1-2 shift. This modification adjusts the holding effort of a clutch or band.
2. 4 This step reviews the 2-3 adapt cells. If pressure readings match or exceed the value listed in the value column, then the PCM modifies the base line pressure on a 2-3 shift. This modification adjusts the holding effort of a clutch or band.
3. 5 This step reviews the 3-4 adapt cells. If pressure readings match or exceed the values listed in the value column, then the PCM modifies the base line pressure on a 3-4 shift. This modification adjusts the holding effort of a clutch or band.
4. 6 This step inspects or repairs any of the components listed. A faulty component may lead to a maximum adapt and long shift during a 1-2 upshift.
5. 7 This step inspects or repairs any of the components listed. A faulty component may lead to a maximum adapt and long shift during a 2-3 upshift.
6. 8 This step inspects or repairs any of the components listed. A faulty component may lead to a maximum adapt and long shift during a 3-4 upshift.
7. 9 This step inspects components located within the valve body, if the fluid pressure gauge readings do not match the commanded PC solenoid valve current to line pressure located in the value column.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
3. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Select TRANS ADAPTS/1-2 ADAPT data on the scan tool. Review the 1-2 TAP cells 4-16. Do any cells display a value equal to or greater than 26.7 psi (1.88 kg/cm 2 )? If so, go to step 6 . If not, go to next step.
4. Select TRANS ADAPTS/2-3 ADAPT data on the scan tool. Review the 2-3 TAP cells 4-16. Do any cells display a value equal to or greater than 26.7 psi (1.88 kg/cm 2 )? If so, go to step 7 . If not, go to next step.
5. Select TRANS ADAPTS/3-4 ADAPT data on the scan tool. Review the 3-4 TAP cells 4-16. Do any cells display a value equal to or greater than 26.7 psi (1.88 kg/cm 2 )? If so, go to step 8 . If not, go to step 9 .
6. Inspect for the following items: The line pressure is too low. The PC solenoid valve is stuck on. The PC solenoid valve has a broken clamp causing leakage. The clutch plates are burned or damaged. The 2nd clutch piston assembly is cracked or damaged. The 2nd clutch return spring and retainer assembly is damaged or out of position. The 2nd clutch piston assembly seals are rolled, damaged or leaking. The 2nd sprag clutch assembly is damaged or not holding. The 1-2 shift solenoid valve is stuck on. The 1-2 shift valves are stuck in 1st gear. Repair any of the above items as necessary. See appropriate OVERHAUL article. Is the repair complete? If so, go to step 14 .
7. Inspect for the following items: Line pressure is too low. The PC solenoid valve is stuck on. The PC solenoid valve has a broken clamp causing leakage. The 3-4 shift solenoid valve bore plug is mis-assembled. The exhaust valve cup plug or the exhaust valve are installed improperly in the driven sprocket support. The 3rd clutch plates are burned or the spline is damaged. The 3rd clutch piston is cracked or damaged, or the checkball is damaged. The 3rd clutch piston seals are cut or rolled. The ball check valve is stuck or missing. Repair any of the above items as necessary. See appropriate OVERHAUL article. Is the repair complete? If so, go to step 14 .
8. Inspect the following items: The line pressure is too low. The PC solenoid valve is stuck on. The PC solenoid valve clamp is broken, causing leakage. The 4th band is burned, slipping or missing. The 4th servo piston is damaged. The 4th servo pin is broken or seized. The 4th servo seals are rolled, cut or damaged. The 4th servo cover is cracked. The 3-4 shift valve bore plug is mis-assembled. Repair any of the above items as necessary. See appropriate OVERHAUL article. Is the repair complete? If so, go to step 14 .
9. Install the pressure gauge and line pressure fitting. See «HYDRAULIC PRESSURE TESTS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__hydraulic-pressure-tests) under PERFORMANCE TESTS. Start the engine. Using the scan tool, command the PC solenoid valve current high, then command the PC solenoid valve current low and observe the pressure gauge. See «PRESSURE GAUGE PARAMETERS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) table. Does the scan tool display match the specified pressure gauge parameters? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step. PRESSURE GAUGE PARAMETERS PC Solenoid Valve Current - Amps Pressure - psi (kg/cm 2 ) 0.10 240-260 (16.87-18.28) 0.20 210-250 (14.77-17.58) 0.30 190-240 (13.34-16.87) 0.40 175-210 (12.30-14.77) 0.50 150-200 (10.55-14.06) 0.60 125-175 (8.79-12.30) 0.70 110-160 (7.73-11.25) 0.80 80-130 (5.62-9.14) 0.90 75-125 (5.27-8.79)
10. Is the line pressure high? If so, go to step 12 . If not, go to next step.
11. Is the line pressure low? If so, go to step 13 .
12. Inspect the following components for high line pressure: The pressure regulator valve is stuck at a high torque signal due to an undersized bore or sediment. The PC solenoid feed valve is stuck. The pressure regulator boost valve is stuck open. Ball check valve is missing. The final drive internal gear snap ring is missing. The actuator feed limit valve is stuck open. Repair any of the above items as necessary. See appropriate OVERHAUL article. Is the repair complete? If so, go to step 14 .
13. Inspect the following components for low line pressure: The scavenge pump body is leaking at the gasket or the pump body. The scavenge pipe is restricted. The scavenge pipe seal is cut or leaking. The primary pump body is leaking at the gasket or the pump body. The scavenge screens are clogged. The pressure regulator valve is stuck due to sediment. The secondary pump body is leaking at the gasket or the pump body. The transmission fluid level is low. The cooler lines are clogged or restricted. Repair any of the above items as necessary. See appropriate OVERHAUL article. Is the repair complete? If so, go to next step.
14. Change the transmission fluid and filter. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Use the scan tool to reset oil life monitor to 100 percent and clear TAPS. Did you complete the repair? If so, go to next step.
15. Perform the following procedure to verify the repair: Select SPECIAL FUNCTIONS. Select TRANSMISSION OUTPUT CONTROLS. Select CLEAR TAP. Drive the vehicle in "D4" to obtain 1-2, 2-3, 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 .

Ask the customer about possible overloading, exceeding the trailer towing limit, or towing in Overdrive. Ensure that the current PCM calibration is correct for the final drive ratio.

DTC P1814: TORQUE CONVERTER OVERSTRESS

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

This diagnostic test checks for unusually high throttle angle and low vehicle speed when the transaxle is in Drive or Reverse. The primary purpose of this DTC is to record the failure record data, because this condition could damage the powertrain or create an unsafe condition.

If the PCM detects an unusually high throttle angle and low vehicle speed when the transaxle is in Drive or Reverse, then DTC P1814 sets. DTC P1814 is a type "C" DTC.

Conditions For Running DTC P1814

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 internal mode switch DTCs P1820, P1822, P1823 or P1825.
4. The transaxle is not in Park or Neutral.
5. The vehicle speed is 5 MPH or less.
6. The TCC slip speed is 1500 RPM or greater.

Conditions For Setting DTC P1814

DTC will set under the following conditions

1. The throttle angle is 79 percent or greater for 12 seconds.

PCM performs the following actions if DTC is set

1. The PCM does not illuminate the MIL.
2. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
3. The PCM stores DTC P1814 in PCM history.

Conditions For Clearing DTC P1814

DTC will clear under the following conditions

1. A scan tool can clear the DTC.
2. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
3. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

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

1. 2 This step inspects the failure records for DTC P1814 occurrences.
2. 4 This step replaces the transmission fluid and filter. If DTC P1814 occurs more than once in the failure records, TCC damage may have occurred.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Review the stored P1814 failure records and select FAIL COUNTER. Is the P1814 fail counter greater than "1"? If so, go to step 4 . If not, go to next step.
3. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
4. Change the transmission fluid and filter. See appropriate AUTOMATIC article in TRANSMISSION SERVICING. Use the scan tool to reset the oil life monitor to 100 percent. Did you complete the procedures? If so, go to next step.
5. Perform the following procedure in order to verify the repair: Select DTC. Select CLEAR INFO. Road test the vehicle with the transaxle in "D4". The vehicle speed must be 5 MPH or less. The TCC slip speed must be 1500 RPM or less. The throttle angle must be 79 percent or less. These conditions must be true for 3 seconds. Select SPECIFIC DTC. Enter DTC P1814. Has the test run and passed? If so, system is okay. If not, go to step 1 .

A simultaneous acceleration and application of the brakes may cause DTC P1814 to occur.

DTC P1820: INTERNAL MODE SWITCH CIRCUIT "A" LOW

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

The internal mode switch is a sliding contact switch attached to the lower control valve body, within the transaxle. The manual valve link assembly then connects the internal mode switch to the manual valve. The four inputs to the PCM from the internal mode switch indicate which position is selected by the gearshift lever. This information is used for engine controls as well as determining the transaxle shift patterns. The input voltage level at the PCM is HI (ignition voltage) when the internal mode switch is open, and LOW when the switch is closed to ground. The state of each input is available for display on the scan tool. The four input parameters represented are signal "A", signal "B", signal "C" and signal "P" (Parity). See INTERNAL MODE SWITCH LOGIC table under DESCRIPTION & OPERATION.

If the PCM detects an internal mode switch transitional state between "D4" and "D3" while the vehicle is in motion, then DTC P1820 sets. DTC P1820 is a type "B" DTC.

Conditions For Running DTC P1820

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.
3. The engine torque is 30-148 ft. lbs. (40-200 N.m).

Conditions For Setting DTC P1820

DTC sets when the following conditions exist

1. The internal mode switch indicates Park for 2 seconds.
2. The internal mode switch indicates a transitional state between "D4" and "D3" for 5 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM assumes a "D4" shift pattern.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
6. The PCM stores DTC P1820 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P1820

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step determines if the fault is internal or external to the transaxle.
2. 4 This step determines if the engine wiring harness circuit or the PCM is at fault.
3. 5 This step determines if the transaxle wiring harness or the internal mode switch is at fault.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Select Internal Mode Switch (IMS) on the scan tool. Place the gearshift lever in "D4". Does the scan tool IMS display DRIVE 4? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Select IMS A/B/C/P on the scan tool. Does internal mode switch signal "A" indicate LOW? If so, go to next step. If not, go to step 5 .
4. Test the internal mode switch signal "A" circuit (771) for a short to ground between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 9 . If not, go to step 8 .
5. Turn ignition off. Reconnect the transaxle in-line 20-way connector. Disconnect the wiring harness at the internal mode switch. Turn ignition on, engine off. Select IMS A/B/C/P on the scan tool. Does internal mode switch signal "A" indicate LOW? If so, go to next step. If not, go to step 7 .
6. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 9 .
7. Replace the internal mode switch. See «INTERNAL MODE SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 9 .
8. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
9. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle in "D4". The system voltage is 8-18 volts. The engine torque is 30-148 ft. lbs. (40-200 N.m). Internal mode switch signal "A" must indicate HI (ignition voltage input) for 0.025 second. Select SPECIFIC DTC. Enter DTC P1820. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, internal mode switch and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1822: INTERNAL MODE SWITCH CIRCUIT "B" HIGH

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

The internal mode switch is a sliding contact switch attached to the lower control valve body, within the transaxle. The manual valve link assembly then connects the internal mode switch to the manual valve. The four inputs to the PCM from the internal mode switch indicate which position is selected by the gearshift lever. This information is used for engine controls as well as determining the transaxle shift patterns. The input voltage level at the PCM is HI (ignition voltage) when the internal mode switch is open and LOW when the switch is closed to ground. The state of each input is available for display on the scan tool. The four input parameters represented are signal "A", signal "B", signal "C" and signal "P" (Parity). See INTERNAL MODE SWITCH LOGIC table under DESCRIPTION & OPERATION.

If the PCM detects an internal mode switch transitional state between "D2" and "D1" while the vehicle is in motion, then DTC P1822 sets. DTC P1822 is a type "B" DTC.

Conditions For Running DTC P1822

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.
3. The engine torque is 30-148 ft. lbs. (40-200 N.m).

Conditions For Setting DTC P1822

DTC sets when the following conditions exist

1. The internal mode switch indicates Park for 2 seconds
2. The internal mode switch indicates a transitional state between "D2" and "D1" for 5 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM assumes a "D4" shift pattern.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
6. The PCM stores DTC P1822 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P1822

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step determines if the fault is internal or external to the transaxle.
2. 4 This step determines if the engine wiring harness circuit or the PCM is at fault.
3. 5 This step determines if the transaxle wiring harness or the internal mode switch is at fault.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Select Internal Mode Switch (IMS) display on the scan tool. Place the gearshift lever in "D4". Does the scan tool IMS display DRIVE 4? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Connect a fused jumper wire from jumper harness terminal "G" to ground. Turn ignition on, engine off. Select IMS A/B/C/P on the scan tool. Does internal mode switch signal "B" indicate LOW? If so, go to step 5 . If not, go to next step.
4. Test the internal mode switch signal "B" circuit (772) for an open between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 9 . If not, go to step 8 .
5. Test the internal mode switch signal "B" circuit (772) for an open between the transaxle in-line 20-way connector and the internal mode switch. Did you find the condition? If so, go to next step. If not, go to step 7 .
6. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 9 .
7. Replace the internal mode switch. See «INTERNAL MODE SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 9 .
8. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
9. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle in "D4". The system voltage is 8-18 volts. The engine torque is 30-148 ft. lbs. (40-200 N.m). Internal mode switch signal "B" must be LOW (zero volts) for 0.025 second. Select SPECIFIC DTC. Enter DTC P1822. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, internal mode switch and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1823: INTERNAL MODE SWITCH CIRCUIT "P" LOW

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

The internal mode switch is a sliding contact switch attached to the lower control valve body, within the transaxle. The manual valve link assembly then connects the internal mode switch to the manual valve. The four inputs to the PCM from the internal mode switch indicate which position is selected by the gearshift lever. This information is used for engine controls as well as determining the transaxle shift patterns. The input voltage level at the PCM is HI (ignition voltage) when the internal mode switch is open and LOW when the switch is closed to ground. The state of each input is available for display on the scan tool. The four input parameters represented are signal "A", signal "B", signal "C" and signal "P" (Parity). See INTERNAL MODE SWITCH LOGIC table under DESCRIPTION & OPERATION.

If the PCM detects an internal mode switch transitional state between Neutral and "D4" while the vehicle is in motion, then DTC P1823 sets. DTC P1823 is a type "B" DTC.

Conditions For Running DTC P1823

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.
3. The engine torque is 30-148 ft. lbs. (40-200 N.m).

Conditions For Setting DTC P1823

DTC sets when the following conditions exists

1. The internal mode switch indicates Park for 2 seconds.
2. The internal mode switch indicates a transitional state between Neutral and "D4" for 5 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM assumes a "D4" shift pattern.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
6. The PCM stores DTC P1823 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P1823

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step determines if the fault is internal or external to the transaxle.
2. 4 This step determines if the engine wiring harness circuit or the PCM is at fault.
3. 5 This step determines if the transaxle wiring harness or the internal mode switch is at fault.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Select Internal Mode Switch (IMS) on the scan tool. Place the gearshift lever in "D4". Does the scan tool IMS display DRIVE 4? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Select IMS A/B/C/P on the scan tool. Is internal mode switch signal "P" LOW? If so, go to next step. If not, go to step 5 .
4. Test the internal mode switch signal "P" circuit (776) for a short to ground between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 9 . If not, go to step 8 .
5. Turn ignition off. Reconnect the transaxle in-line 20-way connector. Disconnect the wiring harness at the internal mode switch. Turn ignition on, engine off. Select IMS A/B/C/P on the scan tool. Is the internal mode switch signal "P" LOW? If so, go to next step. If not, go to step 7 .
6. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 9 .
7. Replace the internal mode switch. See «INTERNAL MODE SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 9 .
8. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
9. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle in "D4". The system voltage is 8-18 volts. The engine torque is 30-148 ft. lbs. (40-200 N.m). Internal mode switch signal "P" must be HI (ignition voltage) for 0.025 second. Select SPECIFIC DTC. Enter DTC P1823. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, internal mode switch and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1825: INTERNAL MODE SWITCH - INVALID RANGE

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

The internal mode switch is a sliding contact switch attached to the lower control valve body, within the transaxle. The manual valve link assembly then connects the internal mode switch to the manual valve. The four inputs to the PCM from the internal mode switch indicate which position is selected by the gearshift lever. This information is used for engine controls as well as determining the transaxle shift patterns. The input voltage level at the PCM is HI (ignition voltage) when the internal mode switch is open and LOW when the switch is closed to ground. The state of each input is available for display on the scan tool. The four input parameters represented are signal "A", signal "B", signal "C" and signal "P" (Parity). See INTERNAL MODE SWITCH LOGIC table under DESCRIPTION & OPERATION.

If the PCM detects a combination of internal mode switch inputs that are invalid, then DTC P1825 sets. DTC P1825 is a type "B" DTC.

Conditions For Running DTC P1825

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.

Conditions For Setting DTC P1825

DTC sets when the following condition exists

1. The PCM detects an invalid internal mode switch range for 5 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM assumes a "D4" shift pattern.
4. The PCM freezes shift adapt functions.
5. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
6. The PCM stores DTC P1825 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P1825

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step tests the internal mode switch for an open ground circuit.
2. 5 This step tests for correct reference voltage from the PCM.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Select Internal Mode Switch (IMS) on the scan tool. Place the gearshift lever in each transaxle range. See «INTERNAL MODE SWITCH LOGIC»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) table under DESCRIPTION & OPERATION. Does each range selected match the scan tool IMS display? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Select IMS A/B/C/P on the scan tool. Place the gearshift lever in each transaxle range. Does the IMS A/B/C/P indicate HI/HI/HI/HI for each range selected? If so, go to step 13 . If not, go to next step.
4. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Select IMS A/B/C/P on the scan tool. Does the scan tool IMS A/B/C/P indicate HI for all range signal states? If so, go to next step. If not, go to step 9 .
5. Turn ignition off. Install Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Turn ignition on, engine off. Using a DVOM and Terminal Test Kit (J-35616-A), measure the voltage at jumper harness terminal "F". Measure the voltage at jumper harness terminal "G". Measure the voltage at jumper harness terminal "H". Measure the voltage at jumper harness terminal "J". Does the voltage measure ignition voltage at all four terminals? If so, go to next step. If not, go to step 10 .
6. Connect a fused jumper wire from jumper harness terminal "F" (signal "A" circuit) to ground while monitoring the scan tool IMS 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 jumper harness terminal "G" (signal "B" circuit) to ground while monitoring the scan tool IMS 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 jumper harness terminal "H" (signal "C" circuit) to ground while monitoring the scan tool IMS 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 12 .
9. Test the internal mode switch signal circuits (771, 772, 773, and 776) that did not indicate HI for a short to ground between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 18 . If not, go to step 17 .
10. Test the internal mode switch signal circuits (771, 772, 773, and 776) that did not indicate ignition voltage for an open between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 18 . If not, go to step 17 .
11. Test the affected internal mode switch signal circuits for a shorted together condition between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 18 . If not, go to step 17 .
12. Test the internal mode switch signal circuits (771, 772, 773, and 776) for an open or shorted condition between the transaxle in-line 20-way connector and the internal mode switch. Did you find a condition? If so, go to step 15 . If not, go to step 16 .
13. Test the internal mode switch ground circuit (1550) for an open between the transaxle in-line 20-way connector and the ground distribution block. Did you find and correct the condition? If so, go to step 18 . If not, go to next step.
14. Test the internal mode switch ground circuit (1050) for an open between the transaxle in-line 20-way connector and the internal mode switch. Did you find a condition? If so, go to next step. If not, go to step 16 .
15. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 18 .
16. Replace the internal mode switch. See «INTERNAL MODE SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 18 .
17. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
18. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Turn ignition on, engine off. The internal mode switch must indicate a valid range for 5 seconds. Select SPECIFIC DTC. Enter DTC P1825. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, internal mode switch and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1842: 1-2 SHIFT SOLENOID CIRCUIT LOW VOLTAGE

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

The 1-2 shift solenoid valve controls transmission fluid pressure acting on the 1-2 and 3-4 shift valves to position the valves for the appropriate gear. The 1-2 shift solenoid valve is a normally open exhaust valve located on the lower control valve body. Ignition voltage is supplied to the solenoid. The output driver module, within the PCM, commands the solenoid on or off by providing a ground path. When the 1-2 shift solenoid valve is commanded on, the PCM senses low voltage. When the 1-2 shift solenoid valve is commanded off, the PCM senses high voltage.

If the PCM detects a continuous open or short to ground in the 1-2 shift solenoid valve circuit, then DTC P1842 sets. DTC P1842 is a type "B" DTC.

Conditions For Running DTC P1842

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.

Conditions For Setting DTC P1842

DTC sets when one of the following conditions exists for at least 5 seconds

1. The 1-2 shift solenoid valve feedback circuit indicates a continuous open or short to ground for 4.3 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM inhibits 3-2 downshifts above 31 MPH.
4. The PCM commands the TCC on in 3rd and 4th gear when in hot mode, if the brake switch status remains closed and no downshifts are commanded.
5. The PCM freezes shift adapt functions.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P1842 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P1842

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 8 This step tests the electrical operation of the solenoid.
2. 9 This step tests the PCM and the wiring to the transaxle.
3. 14 This step verifies that the circuit has the correct resistance.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Is DTC P1845 or P1860 also set? If so, go to next step. If not, go to step 8 .
3. Remove the TRANS fuse. 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 1-2 shift solenoid valve ignition 1 voltage circuit (739) for a short to ground between the underhood fuse block and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 . If not, go to next step.
5. Test the 1-2 shift solenoid valve ignition 1 voltage circuit (839) for a short to ground between the transaxle in-line 20-way connector and the 1-2 shift solenoid valve. Did you find the condition? If so, go to step 20 .
6. Test the 1-2 shift solenoid valve ignition 1 voltage circuit (739) for an open between the underhood fuse block and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 . If not, go to next step.
7. Test the ignition 1 voltage circuit (839) of the 1-2 shift solenoid valve for an open between the transaxle in-line 20-way connector and the 1-2 shift solenoid valve. Did you find the condition? If so, go to step 20 .
8. Use the scan tool to command the 1-2 shift solenoid valve on and off three times. Listen at the transaxle bottom pan. Does the solenoid click when commanded on and off? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
9. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle in-line 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 14 . 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 the PCM connector C2. 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 22 .
12. Test the 1-2 shift solenoid valve control circuit (1222) for a short to ground between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 .
13. Test the 1-2 shift solenoid valve control circuit (1222) for an open between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 . If not, go to step 22 .
14. Turn ignition off. Disconnect the jumper harness from the engine side of the transaxle in-line 20-way connector. Install the jumper harness on the transaxle side of the transaxle in-line 20-way connector. Measure the resistance between jumper harness terminals "E" and "A". Is the resistance 20-40 ohms? If so, go to step 17 . If not, go to next step.
15. Is the resistance greater than 40 ohms? If so, go to next step. If not, go to step 17 .
16. Test the 1-2 shift solenoid valve control circuit (1222) for an open between the transaxle in-line 20-way connector and the 1-2 shift solenoid valve. Test the 1-2 shift solenoid valve ignition 1 voltage circuit (839) for an open between the transaxle in-line 20-way connector and the 1-2 shift solenoid valve. Did you find a condition? If so, go to step 20 . If not, go to step 21 .
17. Measure the resistance from jumper harness terminal "A" to ground. Is the resistance less than 100 ohms? If so, go to next step. If not, go to step 19 .
18. Test the 1-2 shift solenoid valve control circuit (1222) for a short to ground between the transaxle in-line 20-way connector and the 1-2 shift solenoid valve. Did you find the condition? If so, go to step 20 .
19. Measure the resistance between jumper harness terminal "A" and all other jumper harness terminals, except terminals "B" and "E". Is the resistance between terminal "A" and any other terminal, except terminals "B" and "E", less than 100 ohms? If so, go to next step. If not, go to step 21 .
20. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 23 .
21. Replace the 1-2 shift solenoid valve. See «SHIFT SOLENOID VALVES»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-valves) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 23 .
22. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
23. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle in "D4". Allow the transaxle to obtain a 1-2 upshift. Select SPECIFIC DTC. Enter DTC P1842. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, 1-2 shift solenoid valve and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1843: 1-2 SHIFT SOLENOID CIRCUIT HIGH VOLTAGE

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

The 1-2 shift solenoid valve controls transmission fluid pressure acting on the 1-2 and 3-4 shift valves to position the valves for the appropriate gear. The 1-2 shift solenoid valve is a normally open exhaust valve located on the lower control valve body. Ignition voltage is supplied to the solenoid. The output driver module, within the PCM, commands the solenoid on or off by providing a ground path. When the 1-2 shift solenoid valve is commanded on, the PCM senses low voltage. When the 1-2 shift solenoid valve is commanded off, the PCM senses high voltage.

If the PCM detects a continuous short to voltage in the 1-2 shift solenoid valve circuit, then DTC P1843 sets. DTC P1843 is a type "B" DTC.

Conditions For Running DTC P1843

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.
3. The PCM commands the 1-2 shift solenoid valve on.

Conditions For Setting DTC P1843

DTC sets when the following condition exists

1. The 1-2 shift solenoid valve feedback circuit indicates a continuous short to voltage for 4.3 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM commands maximum line pressure.
3. The PCM inhibits 3-2 downshifts above 31 MPH.
4. The PCM commands the TCC on in 3rd and 4th gear when in hot mode, if the brake switch status remains closed and no downshifts are commanded.
5. The PCM freezes shift adapt functions.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P1843 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P1843

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step tests the PCM and the wiring to the transaxle.
2. 5 This step verifies that the circuit has the correct resistance.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Start the engine. Select 1-2 SOL SHORT TO VOLTS on the scan tool. Does the scan tool display indicate a short to voltage? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Connect a test light between jumper harness terminal "A" and ground. Turn ignition on, engine off. Is the test light on? If so, go to next step. If not, go to step 5 .
4. Test the 1-2 shift solenoid valve control circuit (1222) for a short to voltage between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 11 . If not, go to step 10 .
5. Turn ignition off. Disconnect the jumper harness from the engine side of the transaxle in-line 20-way connector. Install the jumper harness on the transaxle side of the transaxle in-line 20-way connector. Measure the resistance between jumper harness terminals "E" and "A". Is the resistance 20-40 ohms? If so, go to step 7 . If not, go to next step.
6. Leave the DVOM test leads connected. Disconnect the wiring harness from the 1-2 shift solenoid valve. Is the resistance less than 100 ohms? If so, go to step 8 . If not, go to step 9 .
7. Measure the resistance between jumper harness terminal "A" and all other jumper harness terminals, except terminals "B" and "E". Is the resistance between terminal "A" and any other terminal, except terminals "B" and "E", less than 100 ohms? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
8. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 11 .
9. Replace the 1-2 shift solenoid valve. See «SHIFT SOLENOID VALVES»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-valves) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 11 .
10. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
11. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Start the engine. Select SPECIFIC DTC. Enter DTC P1843. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, 1-2 shift solenoid valve and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1845: 2-3 SHIFT SOLENOID CIRCUIT LOW VOLTAGE

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

The 2-3 shift solenoid valve controls the transmission fluid pressure acting on the 1-2 and 2-3 shift valves to position the valves for the appropriate gear. The 2-3 shift solenoid valve is a normally open exhaust valve located on the lower control valve body. Ignition voltage is supplied to the solenoid. The output driver module, within the PCM, commands the solenoid on or off by providing a ground path. When the 2-3 shift solenoid valve is commanded on, the PCM senses low voltage. When the 2-3 shift solenoid valve is commanded off, the PCM senses high voltage.

If the PCM detects a continuous open or short to ground in the 2-3 shift solenoid valve circuit, then DTC P1845 sets. DTC P1845 is a type "A" DTC.

Conditions For Running DTC P1845

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.

Conditions For Setting DTC P1845

DTC sets when the following conditions exists

1. The 2-3 shift solenoid valve feedback circuit indicates a continuous open or short to ground for 4.3 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL.
2. The PCM commands an immediate landing to 2nd gear.
3. The PCM commands maximum line pressure.
4. The PCM inhibits TCC engagement.
5. The PCM freezes shift adapt functions.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P1845 in PCM history.

Conditions For Clearing DTC P1845

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 8 This step tests the electrical operation of the solenoid.
2. 9 This step verifies the PCM's ability to command the solenoid.
3. 14 This step verifies that the circuit has the correct resistance.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Is DTC P1842 or P1860 also set? If so, go to next step. If not, go to step 8 .
3. Remove the TRANS fuse. 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 ignition 1 voltage circuit (739) for a short to ground between the underhood fuse block and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 . If not, go to next step.
5. Test the 2-3 shift solenoid valve ignition 1 voltage circuit (839) for a short to ground between the transaxle in-line 20-way connector and the 2-3 shift solenoid valve. Did you find the condition? If so, go to step 20 .
6. Test the 2-3 shift solenoid valve ignition 1 voltage circuit (739) for an open between the underhood fuse block and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 . If not, go to next step.
7. Test the 2-3 shift solenoid valve ignition 1 voltage circuit (839) for an open between the transaxle in-line 20-way connector and the 2-3 shift solenoid valve. Did you find the condition? If so, go to step 20 .
8. Use the scan tool to command the 2-3 shift solenoid valve on and off three times. Listen at the transaxle bottom pan. Does the solenoid click when commanded on and off? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
9. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install the Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Using the Terminal Test Kit (J-35616-A), connect a test light between jumper harness terminals "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 14 . 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 the PCM connector C2. 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 22 .
12. Test the 2-3 shift solenoid valve control circuit (1223) for a short to ground between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 .
13. Test the 2-3 shift solenoid valve control circuit (1223) for an open between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 23 . If not, go to step 22 .
14. Turn ignition off. Disconnect the jumper harness from the engine side of the transaxle in-line 20-way connector. Install the jumper harness on the transaxle side of the transaxle in-line 20-way connector. Using a DVOM and the terminal test kit, measure the resistance between jumper harness terminals "E" and "B". Is the resistance 20-40 ohms? If so, go to step 17 . If not, go to next step.
15. Is the resistance greater than 40 ohms? If so, go to next step. If not, go to step 17 .
16. Test the 2-3 shift solenoid valve control circuit (1223) for an open between the transaxle in-line 20-way connector and the 2-3 shift solenoid valve. Test the ignition 1 voltage circuit (839) for an open between the transaxle in-line 20-way connector and the 2-3 shift solenoid valve. Did you find a condition? If so, go to step 20 . If not, go to step 21 .
17. Measure the resistance from jumper harness terminal "B" to ground. Is the resistance less than 100 ohms? If so, go to next step. If not, go to step 19 .
18. Test the 2-3 shift solenoid valve control circuit (1223) for a short to ground between the transaxle in-line 20-way connector and the 2-3 shift solenoid valve. Did you find the condition? If so, go to step 20 .
19. Measure the resistance between jumper harness terminal "B" and all other jumper harness terminals, except terminals "A" and "E". Is the resistance between terminal "B" and any other terminal, except terminals "A" and "E", less than 100 ohms? If so, go to next step. If not, go to step 21 .
20. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 23 .
21. Replace the 2-3 shift solenoid valve. See «SHIFT SOLENOID VALVES»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-valves) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 23 .
22. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
23. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle in "D4". Allow the transaxle to obtain a 2-3 upshift. Select SPECIFIC DTC. Enter DTC P1845. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, 2-3 shift solenoid valve and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1847: 2-3 SHIFT SOLENOID CIRCUIT HIGH VOLTAGE

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

The 2-3 shift solenoid valve controls the transmission fluid pressure acting on the 1-2 and 2-3 shift valves to position the valves for the appropriate gear. The 2-3 shift solenoid valve is a normally open exhaust valve located on the lower control valve body. Ignition voltage is supplied to the solenoid. The output driver module, within the PCM, commands the solenoid on or off by providing a ground path. When the 2-3 shift solenoid valve is commanded on, the PCM senses low voltage. When the 2-3 shift solenoid valve is commanded off, the PCM senses high voltage.

If the PCM detects a continuous short to voltage in the 2-3 shift solenoid valve circuit, then DTC P1847 sets. DTC P1847 is a type "A" DTC.

Conditions For Running DTC P1847

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.
3. The PCM commands the 2-3 shift solenoid valve on.

Conditions For Setting DTC P1847

DTC sets when the following condition exists

1. The 2-3 shift solenoid valve feedback circuit indicates a continuous short to voltage for 4.3 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL.
2. The PCM commands an immediate landing to 2nd gear.
3. The PCM commands maximum line pressure.
4. The PCM inhibits TCC engagement.
5. The PCM freezes shift adapt functions.
6. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
7. The PCM stores DTC P1847 in PCM history.

Conditions For Clearing DTC P1847

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 3 This step tests the PCM and the wiring to the transaxle.
2. 5 This step verifies that the circuit has the correct resistance.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Select 2-3 SOL SHORT TO VOLTS on the scan tool. Drive the vehicle in "D4". When 3rd or 4th gear is commanded, does the scan tool display indicate a short to voltage? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Install Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Using Terminal Test Kit (J-35616-A), connect a test light between jumper harness terminal "B" and ground. Turn ignition on, engine off. Is the test light on? If so, go to next step. If not, go to step 5 .
4. Test the 2-3 shift solenoid valve control circuit (1223) for a short to voltage between the PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 11 . If not, go to step 10 .
5. Turn ignition off. Disconnect the jumper harness from the engine side of the transaxle in-line 20-way connector. Install the jumper harness on the transaxle side of the transaxle in-line 20-way connector. Using a DVOM and terminal test kit, measure the resistance between jumper harness terminals "E" and "B". Is the resistance 20-40 ohms? If so, go to step 7 . If not, go to next step.
6. Leave the DVOM test leads connected. Disconnect the wiring harness from 2-3 shift solenoid valve. Is the resistance less than 100 ohms? If so, go to step 8 . If not, go to step 9 .
7. Measure the resistance between jumper harness terminal "B" and all other jumper harness terminals, except terminals "A" and "E". Is the resistance between terminal "B" and any other terminal, except terminals "A" and "E", less than 100 ohms? If so, go to next step. If not, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) .
8. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 11 .
9. Replace the 2-3 shift solenoid valve. See «SHIFT SOLENOID VALVES»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__shift-solenoid-valves) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 11 .
10. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
11. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle in "D4". Allow the transaxle to obtain a 3-4 upshift. Select SPECIFIC DTC. Enter DTC P1847. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect connectors at PCM, 2-3 shift solenoid valve and all other circuit connecting points for an intermittent condition. Inspect circuit wiring for intermittent conditions.

DTC P1860: TCC PWM SOLENOID CIRCUIT - ELECTRICAL MALFUNCTION

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

Ignition voltage is provided to the Torque Converter Clutch Pulse Width Modulated (TCC PWM) solenoid valve. The PCM controls the on and off time of the solenoid by providing a ground through the output driver module. The PCM uses a pulse width modulated duty cycle to control application and release of the TCC. When the solenoid is commanded off, the PCM senses high volts. When the solenoid is commanded on, the PCM senses low volts.

If the PCM detects a continuous open, short to ground or short to voltage in the TCC PWM solenoid valve circuit, then DTC P1860 sets. DTC P1860 is a type "B" DTC.

Conditions For Running DTC P1860

DTC will run under the following conditions

1. The system voltage is 8-18 volts.
2. The engine run time is greater than 5 seconds.
3. The TCC PWM solenoid valve duty cycle is 10 percent or less or 90 percent or greater.

Conditions For Setting DTC P1860

DTC sets when the following condition exists

1. The TCC PWM solenoid valve feedback circuit indicates a continuous open, short to ground or short to voltage for 4.3 seconds.

PCM performs the following if DTC is set

1. The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
2. The PCM inhibits 4th gear when the transaxle is in hot mode.
3. The PCM freezes shift adapt functions.
4. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame and failure records.
5. The PCM stores DTC P1860 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.

Conditions For Clearing DTC P1860

DTC will clear under the following conditions

1. The PCM turns off the MIL during the third consecutive trip in which the diagnostic test runs and passes.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the ignition is off long enough to power down the PCM.

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

1. 11 This step tests the PCM and the wiring to the transaxle in-line 20-way connector.
2. 14 This step tests the control circuit for a short to voltage.
3. 16 This step tests the circuit for correct resistance.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Is DTC P1842 or P1845 also set? If so, go to next step. If not, go to step 8 .
3. Remove the TRANS fuse. 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 ignition 1 voltage circuit (739) for a short to ground between the underhood fuse block and the transaxle in-line 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 ignition 1 voltage circuit (1135) for a short to ground between the transaxle in-line 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 ignition 1 voltage circuit (739) for an open between the underhood fuse block and the transaxle in-line 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 ignition 1 voltage circuit (1135) for an open between the transaxle in-line 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 in-line 20-way connector. Additional DTCs may set. Install the Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Using Terminal Test Kit (J-35616-A), connect a test light between jumper harness terminals "U" 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 connector C2. 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 (422) for a short to ground between the PCM connector C2 and the transaxle in-line 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 control circuit (422) and the Ignition 1 voltage circuit (739) for an open between the PCM connector C2 and the transaxle in-line 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 (422) for a short to voltage between the PCM connector C2 and the transaxle in-line 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 in-line 20-way connector. Install the jumper harness on the transaxle side of the transaxle in-line 20-way connector. Measure the resistance between jumper harness terminals "U" 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 (418) for an open between the transaxle in-line 20-way connector and the TCC PWM solenoid valve. Test the ignition "1" voltage circuit (1135) for an open between the transaxle in-line 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 100 ohms? If so, go to next step. If not, go to step 21 .
20. Test the TCC PWM solenoid valve control circuit (418) for a short to ground between the transaxle in-line 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 terminal "U". Is the resistance between terminal "T" and any other terminal, except terminal "U", less than 100 ohms? If so, go to next step. If not, go to step 23 .
22. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 25 .
23. Replace the TCC PWM solenoid valve. See «TCC PULSE WIDTH MODULATION SOLENOID VALVE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__tcc-pulse-width-modulation-solenoid-valve) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 25 .
24. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
25. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Drive the vehicle in "D4". Increase vehicle speed until the TCC is applied. Ensure that DTCs P0741 and P0742 have both run and passed. Select SPECIFIC DTC. Enter DTC P1860. 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. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. Check for moisture and corrosion in wiring and connections. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value. Ensure transaxle fluid is at proper level.

DTC P1868: TRANSMISSION FLUID LIFE

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

Transmission fluid life is determined by monitoring transmission fluid temperature over a period of time. The PCM calculates transmission fluid life based on a set of temperature ranges stored in PCM memory. As the vehicle is driven, a counter increments. The rate at which the counter increments depends on the temperature range in which the transaxle is currently operating in. The higher the temperature range, the faster the counter increments. As the counts increment, the PCM will begin to decrease the fluid life percentage from 100 percent (high fluid life) to zero percent (low fluid life).

If the PCM detects a calculated transmission oil life of 10 percent or less, then DTC P1868 sets. DTC P1868 is a type "C" DTC.

Conditions For Running DTC P1868

DTC will run under the following conditions

1. No transmission fluid temperature DTCs P0711, P0712, or P0713.

Conditions For Setting DTC P1868

DTC will set when the following condition exists

1. The calculated transmission oil life remaining is 10 percent or less.

PCM performs the following actions if DTC is set

1. The PCM does not illuminate the MIL.
2. CHANGE TRANSMISSION FLUID displays on the driver information center.
3. The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as failure records.
4. The PCM stores DTC P1868 in PCM history.

Conditions For Clearing DTC P1868

DTC will clear under the following conditions

1. The PCM clears the DIC when the condition no longer exists.
2. A scan tool can clear the DTC.
3. The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without a non-emission-related diagnostic fault occurring.
4. The PCM cancels the DTC default actions when the fault no longer exists and the DTC passes.

The number listed below refers to step number in the diagnostic procedure

1. 2 This step changes the transmission fluid and filter. It is important to reset the oil life monitor after the fluid and filter are replaced.

1. Did you perform the diagnostic system check? If so, go to next step. If not, see «DIAGNOSTIC SYSTEM CHECK»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under SELF-DIAGNOSTIC SYSTEM.
2. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the failure records. Using the CLEAR INFO function erases the failure records from the PCM. Record the DTC failure records. Clear the DTC. Change the transmission fluid and filter. Use the scan tool to reset the transmission oil life monitor to 100 percent. Did you complete the above procedures? If so, go to next step.
3. Perform the following procedure to verify the repair: Select DTC. Select CLEAR INFO. Ensure that the transmission oil life monitor displays 100 percent. Select SPECIFIC DTC. Enter DTC P1868. Has the test run and passed? If so, system is okay. If not, go to step 1 .

Inspect the transaxle cooling system for possible blockage and restrictions.

HARSH GARAGE SHIFT OR ENGINE HESITATION ON ACCELERATION

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

The Transmission Fluid Pressure (TFP) manual valve position switch consists of two normally open pressure switches. The assembly is attached to the lower control valve body.

The PCM supplies ignition voltage on the two range signal circuits, signal circuit "A" and signal circuit "C". By grounding one of the switches with fluid pressure from the manual valve, the PCM detects a garage shift from Park/Neutral to Reverse or Drive. See TFP MANUAL VALVE POSITION SWITCH LOGIC table under DESCRIPTION & OPERATION. This information is used by the PCM to adjust line pressure during garage shifts.

If one of the following conditions occur, garage shifts may become harsh

1. An open signal circuit.
2. A signal circuit shorted to ground.
3. A damaged or leaking pressure switch seal.
4. Sediment or debris in a pressure switch.
5. Damaged or stuck pressure switch contacts.

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

1. 2 This step tests the indicated range signal to the manual valve range actually selected.
2. 4 This step tests for correct voltage from the PCM.

1. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
2. Install a scan tool. Start the engine and idle at the normal operating temperature. Select TFP SW on the scan tool. Apply the brake pedal. Select each transaxle range. Does each selected transaxle range match the scan tool TFP SW display? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Does the scan tool TFP switch signal "C" parameter indicate HI for both range states? If so, go to next step. If not, go to step 6 .
4. Turn ignition off. Install the Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Turn ignition on, engine off. Using DVOM and Terminal Test Kit (J-35616-A), measure the voltage from jumper harness terminal "N" to ground. Measure the voltage from jumper harness terminal "P" to ground. Does the voltage measure ignition voltage at both terminals? If so, go to next step. If not, go to step 7 .
5. Connect a fused jumper wire from jumper harness terminal "N" (signal "A" circuit) to ground while monitoring the scan tool TFP SW signal "C" parameter. When the signal "A" circuit (1224) is grounded, does the signal "C" circuit (1226) indicate LOW? If so, go to step 8 . If not, go to step 9 .
6. Test the TFP manual valve position switch signal circuit or circuits (1224 and/or 1226) which did not indicate HI for a short to ground between PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct a condition? If so, go to step 13 . If not, go to step 12 .
7. Test the TFP manual valve position switch signal circuit or circuits (1224 and/or 1226) which did not indicate ignition voltage for an open between PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct a condition? If so, go to step 13 . If not, go to step 12 .
8. Test the TFP manual valve position switch signal circuits (1224 and 1226) for a shorted together condition between PCM connector C2 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 13 . If not, go to step 12 .
9. Test the TFP manual valve position switch signal circuits (1224 and 1226) for an open or shorted condition between the transaxle in-line 20-way connector and the TFP manual valve position switch. Did you find a condition? If so, go to next step. If not, go to step 11 .
10. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 13 .
11. Replace the TFP manual valve position switch. See «TFP MANUAL VALVE POSITION SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__tfp-manual-valve-position-switch) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 13 .
12. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Is the replacement complete? If so, go to next step.
13. Perform the following procedure to verify the repair: Start the engine and idle at the normal operating temperature. Select TFP SW on the scan tool. Apply the brake pedal. Select each transaxle range. Does each selected transaxle range match the scan tool TFP SW display? If so, system is okay. If not, go to step 1 .

Inspect wiring for poor connections. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. Check for moisture and corrosion in wiring and connections. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

TRANSAXLE RANGE SELECTOR DISPLAYS INCORRECT RANGE

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

The internal mode switch is a sliding contact switch attached to the lower control valve body, within the transaxle. The manual valve link assembly then connects the internal mode switch to the manual valve. The four inputs to the PCM from the internal mode switch indicate which position is selected by the gearshift lever. This information is used for engine controls as well as determining the transaxle shift patterns. The input voltage level at the PCM is high (ignition voltage) when the internal mode switch is open, and low when the switch is closed to ground. The state of each input is available for display on the scan tool. The four input parameters represented are signal "A", signal "B", signal "C" and signal "P" (Parity).

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

1. 3 This step tests the internal mode switch for an open ground circuit.
2. 5 This step tests for correct reference voltage from the PCM.

1. Install a scan tool. Turn ignition on, engine off. Before clearing the DTC, use the scan tool to record the freeze frame and failure records. Using the CLEAR INFO function erases the freeze frame and failure records from the PCM. Record the DTC freeze frame and failure records. Clear the DTC. Select Internal Mode Switch (IMS) on the scan tool. Place the gearshift lever in each transaxle range. Does each range selected match the scan tool IMS display? If so, see «DIAGNOSTIC AIDS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) . If not, go to next step.
2. Select IMS A/B/C/P on the scan tool. Place the gearshift lever in each transaxle range. Does the IMS A/B/C/P display HI/HI/HI/HI for each range selected? If so, go to step 12 . If not, go to next step.
3. Turn ignition off. Disconnect the transaxle in-line 20-way connector. Additional DTCs may set. Turn ignition on, engine off. Select IMS A/B/C/P on the scan tool. Does the scan tool IMS A/B/C/P parameter indicate HI for all range signal states? If so, go to next step. If not, go to step 8 .
4. Turn ignition off. Install the Jumper Harness (J-44152) on the engine side of the transaxle in-line 20-way connector. Turn ignition on, engine off. Using DVOM and Terminal Test Kit (J-35616-A), measure the voltage at jumper harness terminals "F", "G", "H" and "J". Does the voltage measure ignition voltage at all four terminals? If so, go to next step. If not, go to step 9 .
5. Connect a fused jumper wire from jumper harness terminal "F" (signal "A" circuit) to ground while monitoring the scan tool IMS 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 10 . If not, go to next step.
6. Connect a fused jumper wire from jumper harness terminal "G" (signal "B" circuit) to ground while monitoring the scan tool IMS 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 10 . If not, go to next step.
7. Connect a fused jumper wire from jumper harness terminal "H" (signal "C" circuit) to ground while monitoring the scan tool IMS 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 10 . If not, go to step 11 .
8. Test the internal mode switch signal circuits (771, 772, 773, and 776) that did not indicate HI for a short to ground between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 17 . If not, go to step 16 .
9. Test the internal mode switch signal circuits (771, 772, 773, and 776) that did not indicate ignition voltage for an open between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 17 . If not, go to step 16 .
10. Test the affected signal circuits of the internal mode switch for a shorted together condition between the PCM connector C1 and the transaxle in-line 20-way connector. Did you find and correct the condition? If so, go to step 17 . If not, go to step 16 .
11. Test the internal mode switch signal circuits (771, 772, 773, and 776) for an open or shorted condition between the transaxle in-line 20-way connector and the internal mode switch. Did you find a condition? If so, go to step 14 . If not, go to step 15 .
12. Test the internal mode switch ground circuit (1550) for an open between the transaxle in-line 20-way connector and the ground distribution block. Did you find and correct the condition? If so, go to step 17 . If not, go to next step.
13. Test the internal mode switch ground circuit (1050) for an open between the transaxle in-line 20-way connector and the internal mode switch. Did you find a condition? If so, go to next step. If not, go to step 15 .
14. Replace the transaxle wiring harness. See «TRANSAXLE WIRING HARNESS»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e__transaxle-wiring-harness) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 17 .
15. Replace the internal mode switch. See «INTERNAL MODE SWITCH»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to step 17 .
16. Replace the PCM. See «POWERTRAIN CONTROL MODULE»(/cadillac/seville/v-1998-2004/remont/automatic-trans/#automatic-transaxle-diagnosis-4t80-e) under REMOVAL & INSTALLATION. Did you complete the replacement? If so, go to next step.
17. Turn ignition on, engine off. With the scan tool, observe the IMS display while selecting each transaxle range. Does each selected transaxle range match the scan tool IMS display? If so, system is okay. If not, go to step 2 .

Inspect wiring for poor connections. Check for bent, backed out or damaged terminals, or poor terminal tension. Check for chafed wire or broken wire inside insulation. Check for moisture and corrosion in wiring and connections. When diagnosing intermittent condition, wiggle wiring harness while watching scan tool for change in value.

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 lower control valve body.
2. Install the 1-2 or the 2-3 shift solenoid valve into bore number "3" of the Solenoid Testing Kit (J-44246), and install the factory retainer clip to retain the solenoid. (Scheme 119)
3. Connect the solenoid testing harness supplied with the solenoid tester to the solenoid. (Scheme 120)
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 airflow 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 lower control valve body.

Scheme 119

Scheme 120

REMOVAL & INSTALLATION

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

Removal (DeVille)

1. Record the TRANSAXLE FLUID and ENGINE OIL LIFE indexes.
2. Turn ignition off.
3. Disconnect the negative battery cable.
4. Disconnect the Mass Air Flow/Intake Air Temperature (MAF/IAT) sensor electrical connector.
5. Loosen the intake air duct clamp at the throttle body.
6. Loosen the air filter element cover screws.
7. Remove the air filter element cover, MAF/IAT sensor, and intake air duct. (Scheme 121)
8. Disconnect both PCM connectors.
9. Remove the PCM.

Installation (DeVille)

Note. Inspect the following areas before installing the PCM: No debris in the air filter element assembly, or the MAF/IAT sensor inlet screen that may distort the air flow. No signs of damage to the air filter element assembly, or the intake air duct. If a problem is found, replace as necessary.

Note. If the PCM is being programmed using the off-vehicle method, perform the programming before continuing with the steps listed below. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.

1. Install the PCM.
2. Install the PCM connectors. Tighten the PCM connectors screws to 71 INCH lbs. (8 N.m).
3. Install the intake air duct, MAF/IAT sensor, and the air filter element cover to the throttle body. (Scheme 121)
4. Align and engage the tabs on the air filter element cover with the slots in the air filter element housing.
5. Tighten the air element cover screws to 35 INCH lbs. (4 N.m).
6. Tighten the intake air duct clamp at the throttle body. Tighten the clamp to 27 INCH lbs. (3 N.m).
7. Reconnect the MAF/IAT sensor connector.
8. Connect the negative battery cable.
9. Program the PCM. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.

Scheme 121

Removal (Seville)

1. Record the TRANSAXLE FLUID and ENGINE OIL LIFE indexes.
2. Turn ignition off.
3. Disconnect the negative battery cable.
4. Remove the screw retaining the intake air duct/resonator (3) to the PCM housing. (Scheme 122)
5. Unsnap the air filter housing clamps on top of the air cleaner housing assembly.
6. Pull the intake air duct/resonator assembly (2) up enough to remove the air cleaner cover (3) and the PCM. (Scheme 123)
7. Slide the air cleaner element assembly toward the fender to separate the air cleaner element assembly from the air inlet assembly.
8. Loosen the PCM connector attaching bolts.
9. Disconnect both PCM connectors.
10. Remove the PCM (1). (Scheme 124)

Installation (Seville)

Note. If the PCM is being programmed using the off-vehicle method, perform the programming before continuing with the steps listed below. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.

1. Install the PCM (1). (Scheme 124)
2. Install the PCM connectors. Tighten the PCM connectors screws to 71 INCH lbs. (8 N.m).
3. Install the air cleaner cover (3) onto the air inlet housing. (Scheme 123)
4. Snap the assembly clamps into place.
5. Align the intake air duct/resonator assembly (3) into place. (Scheme 122)
6. Install the screw onto the intake air duct/resonator assembly. Tighten the intake air duct clamp to 27 INCH lbs. (3 N.m).
7. Connect the negative battery cable.
8. Program the PCM. See appropriate BODY CONTROL MODULES article in ACCESSORIES & EQUIPMENT.

Scheme 122

Scheme 123

Scheme 124

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

SHIFT SOLENOID VALVES

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

Removal

Remove the left sound insulator. Rotate the stoplamp switch (2) counterclockwise, then pull to remove the switch. (Scheme 125) Disconnect the electrical connectors from the switch.

Installation

1. Connect the stoplamp switch electrical connectors to the stoplamp switch. Install the stoplamp switch into the retainer. Press the switch into the retainer until the switch plunger is fully depressed into the switch barrel.
2. Rotate the switch clockwise until travel has stopped and the switch locks fully into position. (Scheme 125) Install sound insulator.

Scheme 125

TCC PULSE WIDTH MODULATION SOLENOID VALVE

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

TRANSAXLE WIRING HARNESS

Note. The transaxle wiring harness consists of two separate harnesses, the Transaxle Wiring Harness Assembly (GM P/N 15320475) and the Transaxle Wiring Extension Harness Assembly (GM P/N 15320478). To avoid the unnecessary replacement of parts, determine which harness contains the fault and replace only that harness.

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

TFP MANUAL VALVE POSITION SWITCH

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

TFT SENSOR

Note. Manufacturer does not provide on-vehicle removal and installation procedure for this component. See appropriate OVERHAUL article.

Note. Removal and installation of vehicle speed sensor and input speed sensor is an un-bolt and bolt-on procedure. Only torque specifications are given. See TORQUE SPECIFICATIONS .

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

COMPONENT RESISTANCE

Connect DVOM between specified terminals at component or at transaxle in-line 20-way connector to transaxle. Measure individual component resistance at specified temperature. See COMPONENT RESISTANCE SPECIFICATIONS table. If resistance is not as specified, replace appropriate component. (Scheme 72)

COMPONENT RESISTANCE SPECIFICATIONS

Scheme 126

Scheme 127

Scheme 128

Scheme 129

Scheme 130

Scheme 131

Scheme 132

Scheme 133

Scheme 134

Scheme 135

Scheme 136

Scheme 137

Scheme 138

Scheme 139

Scheme 140

Scheme 141

Scheme 142

Scheme 143

Scheme 144

Scheme 145

Scheme 146

Scheme 147

Scheme 148

Transaxle Electronic Control System Wiring Diagram (2001-02 DeVille). Scheme 149

Transaxle Electronic Control System Wiring Diagram (2001-02 Seville). Scheme 150

See also:
• TFP MANUAL VALVE POSITION SWITCH LOGIC
• SYMPTOM DIAGNOSIS
• PRELIMINARY INSPECTION
• LINE PRESSURE ADAPTER & GAUGE INSTALLATION
• DIAGNOSTIC TROUBLE CODE DEFINITIONS
• P0218
• P0502
• P0503
• P0711
• P0712
• P0713
• P0716
• P0717
• P0719
• P0724
• P0731
• P0732
• P0733
• P0734
• P0741
• P0742
• P0748
• P0751
• P0752
• P0756
• P0757
• P1811
• P1814
• P1820
• P1822
• P1823
• P1825
• P1842
• P1843
• P1845
• P1847
• P1860
• P1868
• TROUBLE SHOOTING
• CLEARING DIAGNOSTIC TROUBLE CODES
• TRANSAXLE WIRING HARNESS
• TFT SENSOR
• HYDRAULIC PRESSURE TESTS
• SHIFT SOLENOID LEAK TEST
• SHIFT SOLENOID VALVES
• TCC PULSE WIDTH MODULATION SOLENOID VALVE
• TFP MANUAL VALVE POSITION SWITCH
• TORQUE SPECIFICATIONS