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Wiring diagrams Section: Automatic Trans

Automatic Transaxle Hydraulic Diagrams - 4T80-E

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Automatic Transaxle Diagnosis - 4T65-E: Other Oldsmobile Aurora II

Automatic Trans 24 illustrations ~6430 words

GEAR RATIOS

Gear Range	Gear Ratio
1st	2.92:1
2nd	1.57:1
3rd	1.00:1
4th	0.71:1
Reverse	2.39:1

TRANSAXLE GEAR RATIOS

ADAPT FUNCTION

The 4T65-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

The clutch fiber plates.
The springs and seals.
The apply bands.

The PCM maintains information for the following transaxle adaptive systems

Upshift Adapts (1-2, 2-3 & 3-4)

The PCM monitors the Input Shaft Speed (ISS) sensor and the Vehicle Speed Sensor (VSS) to determine when an upshift has started and completed. The PCM measures the time for the upshift. If the upshift time is longer than a calibrated value, then the PCM will adjust the current to the Pressure Control (PC) solenoid valve to increase the line pressure for the next shift in the same torque range. If the upshift time is shorter than the calibrated value, then the PCM will decrease the line pressure for the next shift in the same torque range.

Steady State Adapts

The PCM monitors the ISS sensor and the VSS after an upshift to determine the amount of clutch slippage. If excessive slippage is detected, then the PCM will adjust the current to the PC solenoid valve. This will increase the line pressure to maintain the proper gear ratio for the commanded gear.

The Transmission Adaptive Pressure (TAP) information is divided into 13 units called cells. The cells are numbered 4 through 16. Each cell represents a given torque range. TAP cell 4 is the lowest adaptable torque range and TAP cell 16 is the highest adaptable torque range. It is normal for TAP cell values to display zero or negative numbers. This indicates that the PCM has adjusted line pressure at or below the calibrated base pressure.

Clearing Transmission Adaptive Pressure

Updating TAP information is a learning function of the PCM designed to maintain acceptable shift times. It is not recommended that TAP information be reset unless one of the following repairs has been made

Transaxle overhaul or replacement.
Repair or replacement of an apply or release component (clutch, band, piston, servo).
Repair or replacement of a component or assembly which directly affects line pressure.

Resetting the TAP values using a scan tool will erase all learned values in all cells. As a result, the PCM will need to relearn TAP values. Transaxle performance may be affected as new TAPs are learned. The PCM must also relearn TAP values when the PCM or the transaxle is replaced.

TRANSAXLE COMPONENTS & SYSTEMS

Note. For transaxle electronic component locations (Scheme 289)

The mechanical components of this unit are as follows

A torque converter with an Electronically Controlled Capacity Clutch (ECCC).
A drive link assembly.
Four multiple disk clutch assemblies: Input, 2nd, 3rd and 4th.
Three friction bands: Forward band, 2-1 band and Reverse band.
Two planetary gear sets: Input and Reaction.
Three one-way clutches: one roller clutch (1-2 support) and two sprag clutches (3rd and Input).
A final drive and differential assembly.
One control valve assembly.
One vane type oil pump.

The electrical components of this unit are as follows

Two shift solenoid valves: 1-2 and 2-3.
A Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid valve.
A Pressure Control (PC) solenoid valve.
An Transmission Fluid Temperature (TFT) sensor.
Two speed sensors: input shaft and vehicle speed sensors.
An Transmission Fluid Pressure (TFP) manual valve position switch.
Either an internal mode switch or an exterior-mounted transaxle range switch.
An transaxle internal wiring harness assembly.

Input Shaft Speed Sensor

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

The ISS sensor mounts in the case cover, next to the input shaft speed sensor reluctor wheel assembly. An air gap of 0.0032-0.0834 in (0.08-2.12 mm) occurs between the sensor and the teeth on the speed sensor reluctor wheel as the drive sprocket rotates. The speed sensor reluctor wheel is secured to and turns with the drive sprocket by the tangs on the drive sprocket forward thrust washer.

The sensor consists of a permanent magnet surrounded by a coil of wire. As the turbine shaft rotates the speed sensor reluctor wheel and the drive sprocket, an AC signal is produced by the ISS sensor. This AC signal consists of a voltage and frequency that changes based on vehicle speed. The PCM uses the frequency portion of this signal to determine input shaft speed. Higher input shaft speeds induce a higher frequency and a higher voltage measurement at the sensor. The voltage portion of the signal is used in diagnostic procedures.

Sensor resistance should measure between 820-1020 ohms at 68°F (20°C). Output voltage will vary with the vehicle speed from a minimum of 0.5 volts AC at 300 RPM to 200 volts at 6000 RPM.

Pressure Control Solenoid Valve

The Pressure Control (PC) solenoid valve is a precision electronic pressure regulator that controls transmission line pressure based on current flow through its coil windings. As current flow is increased, the magnetic field which is produced by the coil moves the solenoid's plunger further away from the exhaust port. Opening the exhaust port decreases the output fluid pressure, which is regulated by the PC solenoid valve. This ultimately decreases line pressure. The PCM controls the PC solenoid valve based upon various inputs including throttle position, fluid temperature, MAP sensor, and gear state.

The PCM controls the PC solenoid valve on a positive duty cycle at a fixed frequency of 292.5 Hz (cycles per second). Duty cycle is defined as the percentage of time when current flows through the solenoid coil during each cycle. A higher duty cycle provides a greater current flow through the solenoid. The high (positive) side of the PC solenoid valve electrical circuit at the PCM controls the PC solenoid valve operation. The PCM provides a ground path for the circuit, monitors average current, and continuously varies the PC solenoid valve duty cycle to maintain the correct average current flowing through the PC solenoid valve. See PC SOLENOID VALVE DUTY CYCLE table.

The PC solenoid valve resistance should measure between 3-5 ohms when measured at 68°F (20°C).

Duty Cycle %	Current (Amps)	Line Pressure
+5	.02	Maximum
+90	1.1	Minimum

PC SOLENOID VALVE DUTY CYCLE

Transaxle Electrical Connector

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

The following items can affect the electrical connection

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

Remember the following points

In order to remove the connector, squeeze the two tabs toward each other and pull straight up without pulling by the wires.
Limit twisting or wiggling the connector during removal. Bent pins can occur.
Do not pry the connector off with a screwdriver or other tool.
Visually inspect the seals to ensure that they are not damaged during handling.
In order 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.
The connector should click into place with a positive feel and/or noise.
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 289

Vehicle Speed Sensor

The Vehicle Speed Sensor (VSS) is a magnetic inductive pickup that relays vehicle speed information to the PCM. The PCM uses this information to control shift timing, line pressure, and TCC apply and release.

The VSS mounts in the case extension at the vehicle speed sensor reluctor wheel, which is pressed onto the final drive carrier assembly. An air gap of 0.011-0.062" (0.27-1.57 mm) occurs between the sensor and the teeth on the vehicle speed sensor reluctor wheel as the final drive carrier assembly rotates.

The sensor consists of a permanent magnet surrounded by a coil of wire. As the vehicle speed sensor reluctor wheel on the final drive carrier assembly rotates, an AC signal is produced by the VSS. This AC signal consists of a voltage and frequency that changes based on vehicle speed. The PCM uses the frequency portion of this signal to determine vehicle speed. Higher vehicle speeds induce a higher frequency and a higher voltage measurement at the sensor. The voltage portion of the signal is used in diagnostic procedures.

Sensor resistance should measure between 1650-2200 ohms at 68°F (20°C). Output voltage will vary with vehicle speed from a minimum of 0.5 volts AC at 100 RPM to 200 volts at 6000 RPM.

1-2 & 2-3 Shift Solenoid Valves

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

Gear Range		Solenoid Position
"D" (Drive)
1st Gear		1-2 ON/2-3 ON
2nd Gear		1-2 OFF/2-3 ON
3rd Gear		1-2 OFF/2-3 OFF
Overdrive		1-2 ON/2-3 OFF
"3" (3rd)
3rd Gear		1-2 OFF/2-3 OFF
2nd Gear		1-2 OFF/2-3 ON
1st Gear		1-2 ON/2-3 ON
"2" (2nd)
2nd Gear		1-2 OFF/2-3 ON
1st Gear		1-2 ON/2-3 ON
"1" (Low)
1st Gear		1-2 ON/2-3 ON
"R"(Reverse)		1-2 ON/2-3 ON
"N" Or "P" (Neutral Or Park)		1-2 ON/2-3 ON

SHIFT SOLENOID OPERATION

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

Shift solenoid resistance should measure between 19-24 ohms when measured at 68°F (20°C), and between 24-31 ohms when measured at 190°F (88°C).

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

POWERTRAIN CONTROL MODULE

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 305)- (Scheme 312).

Application	Location
Aurora	Left Side Of Engine Compartment, In Air Cleaner

POWERTRAIN CONTROL MODULE LOCATION

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

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

Note. Stored DTCs may be retrieved from PCM memory using a factory recommended scan tool. DTCs cannot be retrieved by grounding 16-pin Data Link Connector (DLC). Connecting scan tool into DLC (located under left side of instrument panel) enables user to read DTCs and check system voltages on serial data line.

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

If MIL is illuminated, DTC(s) are currently being detected. If MIL is off, and PCM has detected a circuit or sensor problem, DTC(s) will be stored in computer memory.

SHIFT INTERLOCK SYSTEM

Note. For additional information, see appropriate SHIFT INTERLOCK SYSTEMS article.

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.

Connect the scan tool.
Ensure the gear selector is in Park and set the parking brake.
Start the engine.
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
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.
Check the garage shifts as follows: Apply the brake pedal and ensure the parking brake is set. Move the gear selector through the following ranges: Park to Reverse, Reverse to Neutral, Neutral to Drive. Pause 2 to 3 seconds in each gear position. Verify the gear engagements are immediate and not harsh.
Monitor transaxle range on the scan tool as follows: Apply the brake pedal and ensure the parking brake is set. Move the gear selector through all ranges. Pause 2 to 3 seconds in each range. Return gear selector to Park. Verify that all selector positions match the scan tool display.
Check throttle angle input as follows: Apply the brake pedal and ensure the parking brake is set. Ensure the gear selector 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.

Part Throttle Detent Downshift

Place the gear selector in the Overdrive position.
Accelerate the vehicle to 40-55 MPH in 4th gear.
Quickly increase throttle angle to greater than 50 percent.
Verify the following: The TCC releases. The transaxle downshifts immediately to 3rd gear.

Full Throttle Detent Downshift

Place the gear selector in the Overdrive position.
Accelerate the vehicle to speeds of 40-55 MPH in 4th gear.
Quickly increase throttle angle to 100 percent.
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 gear selector in the Overdrive position. Accelerate the vehicle to 40-55 MPH in 4th gear. Release the throttle while moving the gear selector to 3rd. Verify the following

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

Manual 4-2 Downshift

Place the gear selector in the Overdrive position. Accelerate the vehicle to 40-45 MPH. Release the throttle while moving the gear selector to 2nd. Verify the following

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

Manual 4-1 Downshift

Place the gear selector in the Overdrive position. Accelerate the vehicle to 40 MPH. Release the throttle while moving the gear selector to 1st. Verify the following

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

Coasting Downshifts

Place the gear selector in the Overdrive position. Accelerate the vehicle to 4th gear with the TCC applied. Release the throttle and lightly apply the brakes. Verify the following

The TCC releases.
Downshifts occur at speeds shown in the shift speed chart. See «SHIFT SPEED SPECIFICATIONS»(ref-132617-S42563652512002012400000) .

Manual Gear Range Selection

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

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

Reverse

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

Manual 1st

With the vehicle stopped, move the gear selector to 1st. Accelerate the vehicle to 20 MPH. Verify the following

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

Manual 2nd

With the vehicle stopped, move the gear selector to 2nd. Accelerate the vehicle to 35 MPH. Verify the following

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

Manual 3rd

With the vehicle stopped, move the gear selector to 3rd. Accelerate the vehicle to 40 MPH. Verify the following

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

Scheme 290

Scheme 290: SHIFT SPEED SPECIFICATIONS

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.

If Shudder Occurs After TCC Has Applied

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

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

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

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

Spark Plugs Inspect for cracks, high resistance or a broken insulator.
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.
Coil Look for a black discoloration on the bottom of the coil. This indicates arcing while the engine is misfiring.
Fuel Injector The filter may be plugged.
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.
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.
MAP/MAF Sensor -- Like a vacuum leak, the engine will not get the correct amount of fuel for proper engine operation.
Carbon On The Intake Valves Carbon restricts the proper flow of air/fuel mixture into the cylinders.
Flat Cam Valves do not open enough to let the proper fuel/air mixture into the cylinders.
Oxygen Sensor This sensor may command the engine too rich or too lean for too long.
Fuel Pressure This may be too low.
Engine Mounts Vibration of the mounts can be multiplied by TCC engagement.
Axle Joints Check for vibration.
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.
Cylinder Balance Bad piston rings or poorly sealing valves can cause low power in a cylinder.
Fuel Contamination This causes poor engine performance.

HYDRAULIC PRESSURE TESTS

WARNING

Keep the brakes applied at all times to prevent unexpected vehicle motion. Personal injury may result if the vehicle moves unexpectedly.

CAUTION

Total test running time should not be longer than two minutes, or transaxle damage could occur.

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

Install a scan tool.
Start the engine and set the parking brake.
Check for a stored Diagnostic Trouble Code (DTC). See «DIAGNOSTIC SYSTEM CHECK»(ref-132617-S25641455412002012400000) under SELF-DIAGNOSTIC SYSTEM.
Repair the vehicle, if necessary.
Check the transmission fluid level. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
Check the manual linkage for proper adjustment. See appropriate AUTOMATIC article in TRANSMISSION SERVICING.
Turn the engine off. Remove the oil pressure test hole plug and install the Pressure Gauge (J 21867). (Scheme 291)
Put the gear selector in Park range and set the parking brake.
Start the engine and allow the engine to warm up at idle.
Access the Pressure Control (PC) solenoid valve control test on the scan tool.
Increase the PC solenoid actual current from zero to one amp in 0.1 amp increments. Allow the pressure to stabilize for five seconds after each pressure change. Read the corresponding line pressure on the pressure gauge.
Compare the data to the table. See «PC SOLENOID CURRENT & LINE PRESSURE SPECIFICATIONS»(ref-132617-S10547081702002012400000) table.
If pressure readings differ greatly from the table, See «SYMPTOM DIAGNOSIS»(ref-132617-S04859075362002012400000) under TROUBLE SHOOTING.
Shut the engine off. Remove the pressure gauge.
Apply sealant (GM P/N 12345382) to the oil pressure test hole plug.
Install the oil pressure test hole plug. Tighten the plug to 106 INCH lbs. (12 N.m).

PC Solenoid Current (Amps) (1)	Psi (kg/cm 2 )
.0	243-310 (17.1-21.8)
.10	241-308 (16.9-21.7)
.20	234-305 (16.5-21.4)
.30	225-300 (15.8-21.1)
.40	210-288 (14.8-20.2)
.50	190-276 (13.4-19.4)
.60	170-254 (12.0-17.9)
.70	145-222 (10.2-15.6)
.80	115-178 (8.1-12.5)
.90	82-130 (5.8-9.1)
1.00	68-93 (4.8-6.5)
1.10	65-80 (4.6-5.6)
(1) PC solenoid current is increased using scan tool with engine at 1400 RPM.

(1)	PC solenoid current is increased using scan tool with engine at 1400 RPM.

PC SOLENOID CURRENT & LINE PRESSURE SPECIFICATIONS

Scheme 291

CLUTCH & SERVO AIR CHECKS

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

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.

Action Taken By PCM

PCM performs the following actions if DTC is set

The PCM does not illuminate the MIL.
The PCM freezes shift adapts.
The PCM records the operating conditions when the conditions for setting the DTC are met. The PCM stores this information as freeze frame records.
The PCM stores DTC P0218 in PCM history.

The PCM performs the following if DTC is set

The PCM illuminates the MIL during the second consecutive trip in which the conditions for setting the DTC are met.
The PCM commands maximum line pressure.
The PCM freezes shift adapts.
The PCM calculates vehicle speed from the input shaft speed sensor for shift timing.
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.
The PCM stores DTC P0502 in PCM history during the second consecutive trip in which the conditions for setting the DTC are met.