Automatic Transmission: Other Suzuki Verona I

Personal Injury Precaution

Refer to PERSONAL INJURY PRECAUTION .

Mechanical

1. Torque converter with TCC
2. Drive link assembly
3. 2 multiple disk clutch assemblies: Clutch B, E
4. 3 multiple brake assemblies: Brake C, D, F
5. Lock-up clutch valve
6. 2 planetary gear sets
7. 1 oil pump
8. Final drive and differential assembly

Electronic

1. 2 shift solenoid valve (sol. 1, 2)
2. 4 pressure control solenoid valve (EDS)
3. 2 speed sensors: A/T ISS and A/T OSS
4. Fluid temperature sensor
5. Automatic transaxle control module (TCM)
6. Wiring harness assembly

Planetary Gears

The ZF 4HP 16 automatic transaxle is equipped with a sun gear, 4 planetary gears, planetary carrier, ring gear. Each gear is located one directly behind the other and are linked together. In other words, front ring gear is permanently linked to rear planet carrier, front planet carrier is linked to rear ring gear.

The individual gear ratios are obtained by linking together the gear set elements in different ways by means of clutches and brakes.

On the 4HP 16, the power flow is directed into the planetary gear set via rear planet carrier or rear sun gear, or via both simultaneously, depending on the gear in question. The output is always via the front planet carrier.

Scheme 136

Shift Elements: Multi-disc Clutches and Brakes

The purpose of the shift elements is to perform shifts under load without the tractive flow being interrupted. The shift elements consist of the following.

Scheme 137

The shift elements are engaged hydraulically. The pressurized oil reaches the space between the cylinder and piston, as a result the discs are compressed. The clutch/brake is engaged when the oil pressure drops, the cup spring acting on the piston presses the piston back into its initial position. The clutch/brake is now released again.

Depending on the gear, the multi-disc clutches B and E supply the engine torque to the planetary gear train, with multi-disc brakes C, D and F directing the torque into the housing.

The dynamic pressure at clutches B and E is equal: i.e. the dynamic pressure in front of and behind the piston is equal. This equalizing effect is achieved in the following way.

The space between the baffle plate and piston is filled with unpressurized oil. A dynamic pressure dependent on the engine speed builds up. The space between pressure also builds up. However, there is simultaneously a static pressure, which causes the clutch to engage. If the static pressure is relieved, the cup spring is able to force the piston back into its original position.

The advantages of this dynamic pressure equalization are

1. Reliable clutch opening in all speed ranges
2. Smoother shifts.

Parking Lock

The parking lock is actuated via the selector lever when in position P. It protects the vehicle mechanically against rolling away.

The stop plate is actuated by the selector shaft, which is permanently connected to the selector lever via a pull cable. The parking lock pawl on the parking lock gear is welded onto the lateral shaft of the transaxle and this prevents the drive wheels from turning.

This blocks the driven wheels.

Scheme 138

Valve Body

Valve body performs the following tasks

1. Generates the line pressure needed for actuating the shift elements.
2. Actuates the individual shift elements via the clutch valves.
3. Assures limited operation of the automatic transaxle in the event of the electronics failing.
4. Actuating the lock-up clutch.
5. Generating the lubricating pressure for the transaxle.

Scheme 139

Selector Lever/Program Switch

The driver engages the travel position via the selector lever

P: Park Position

R: Reverse

N: Neutral

D: Forward Speeds

Park/Neutral Position Switch

The Park/Neutral Position Switch is located on the selector shaft and informs the TCM of the current selector lever position P-R-N-D-3-2-1.

The selector lever position is transmitted to the TCM in encoded form along 4 lines. The encoding is such that malfunctions in the connecting lead are identified.

The Park/Neutral Position Switch is located on the selector shaft, which is connected to the selector lever via a pull cable. In addition, the Park/Neutral Position Switch controls the starter interlock, the reversing light and the selector lever position indicator on the instrument panel.

Signal Combination

SIGNAL COMBINATION CHART

Scheme 140

Automatic Transaxle Output Speed Sensor (A/T OSS)

The vehicle A/T OSS is a magnetic inductive pickup that relays information relative to vehicle speed to the TCM. Vehicle speed information is used by the TCM to control shift timing, line pressure, and TCC (lock-up clutch) apply and release.

The output speed sensor mounts in the case at the speed sensor rotor, which is pressed onto the spur gear. An air gap of 0.1 - 1.3 mm (0.004 - 0.05 in.) is maintained between the sensor and the teeth on the spur gear teeth. The sensor consists of a permanent magnet surrounded by a coil of wire.

As the differential rotates, an AC signal is generated by the output speed sensor (OSS).

Scheme 141

Automatic Transaxle Input Speed Sensor (A/T ISS)

The A/T ISS is a magnetic inductive pickup that relays information relative to transaxle input speed to the TCM. The TCM uses transaxle input speed information to control line pressure, TCC apply and release and transaxle shift patterns. This information is also uses to calculate the appropriate operating gear ratios and TCC slippage. The input speed sensor mounts onto piston B that is inside of valve body.

An air gap of 1.8 - 2.2 mm (0.07 - 0.086 in.) is maintained between the sensor and the piston B.

The sensor consists of a permanent magnet surrounded by a coil of wire. As the piston B is driven by the turbine shaft, an AC signal induced in the input speed sensor.

Higher vehicle speeds induce a higher frequency and voltage measurement at the sensor.

Sensor resistance should measure between 825 - 835 ohms at 20 °C (68 °F). Sensor can measure from 1,000 - 8,000 Hz.

Scheme 142

The shift solenoids are 2 identical, normally open electronic exhaust work that control upshifts and downshifts in all forward gear ranges. These shift solenoids valves together in a combination of ON and OFF sequences to control the line pressure and shift mechanisms (clutches, brakes).

Solenoid 1 controls the high or low of the line pressure (flow to each clutch valve) by the operation type (ON/OFF), i.e. solenoid 1 is ON, line pressure will be low (87 -116 psi [6 - 8 bar]), solenoid 1 is OFF, line pressure will be high (232 - 261 psi [16 - 18 bar]).

Solenoid 2 controls the oil flow to clutch valve E or lock-up clutch valve by the ON/OFF signal.

The TCM monitors numerous inputs to determine the appropriate solenoid state combination and transaxle gear for the vehicle operating conditions.

SHIFT SOLENOID VALVE OPERATING CONDITIONS

SHIFT SOLENOID VALVE RESISTANCE SPECIFICATION

Scheme 143

The pressure control valve (EDS valve 3, 4, 5, 6) is a precision electronic pressure regulator that controls the operation of the clutches, brakes and the lock-up clutch.

The valve reduces the system pressure with which the downstream solenoid valves and electrical pressure regulating valves are supplied. It is possible to use smaller solenoid valves as a result. The EDS require a constant input pressure.

Scheme 144

The TFT sensor is a positive temperature coefficient thermistor (temperature sensitive resistor) that provides information to the TCM regarding transaxle fluid temperature. The temperature sensor is located in valve body. Calculated temperature is a factor used to determine the shift time and shift delay time.

The internal electrical resistance of the sensor varies in relation to the operating temperature of the transaxle fluid (see chart).

Scheme 145

The TCM sends a 5 volt reference signal to the temperature sensor and measures the voltage rise in the electrical circuit. A higher fluid temperature creates a higher resistance in the temperature sensor, thereby measuring a lower voltage signal.

Scheme 146

The TCM measures this voltage as another input to help control line pressure, shift schedules and TCC apply. When transaxle fluid temperature reaches 140 °C (284 °F) the TCM enters "hot mode". Above this temperature the TCM modifies transaxle shift schedules and TCC apply in an attempt to reduce fluid temperature by reducing transaxle heat generation. During hot mode the TCM applies the TCC at all times in 4th gear. Also, the TCM commands the 2 - 3 and 3 - 4 shifts earlier to help reduce fluid heat generation. Hot mode may not be available on some applications.

TRANSAXLE SENSOR SPECIFICATION

Transaxle Electrical Connector

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

The following items can affect the electrical connections

1. Bent pins in the connector from rough handling during connection and disconnection.
2. Wires backing away from the pins or coming unclamped (in either internal or 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 during reconnection.
5. Excessive transaxle fluid leaking into the connector, wicking up into the external wiring harness, and degrading the wire insulation.
6. Water/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. Broken/cracked connector assembly.
10. Points to remember when working with transaxle wiring connector assembly.
11. To remove the connector, squeeze the 2 tabs towards each other and pull straight up (refer to illustration).

Scheme 147

Carefully limit twisting or wiggling the connector during removal. Bent pins can occur.

DO NOT pry the connector off with a screwdriver or other tool.

To reinstall the external wiring connector, first orient the pins by lining up 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.

Transaxle Control Module (TCM)

The transaxle control module (TCM) is an electronic device which monitors inputs to control various transaxle functions including shift quality and transaxle sensors, switches, and components to process for use within its' control program. Based on this input information, the TCM controls various transaxle output functions and devices.

Data Link Connector (DLC)

The data link connector (DLC) is a multiple cavity connector. The DLC provides the means to access serial data from the TCM to aid in powertrain diagnosis. The DLC allows the technician to use a scan tool to monitor various systems and display diagnostic trouble codes (DTCs). The DLC connector is located within the driver's compartment, directly below the steering column.

Scheme 148

Throttle Position Sensor

1. Provides throttle position data to the TCM for determining shift patterns and TCC apply/release.
2. An incorrect throttle position sensor input could causes erratic or shift pattern, poor shift quality or TCC function

Automatic Transaxle Output (Shaft) Speed Sensor

1. Provides vehicle speed data to the TCM for determining shift patterns and TCC apply/release, and gear ratio calculations.
2. An incorrect throttle position sensor input could causes erratic or shift pattern, poor shift quality or TCC function

Automatic Transaxle Input (Shaft) Speed Sensor

Provides transaxle input speed data to the TCM for determining shift patterns and TCC apply/release, and gear ratio.

Engine Coolant Temperature Sensor

1. Provides coolant temperature data to the TCM for determining initial TCC engagement.
2. An incorrect engine coolant temperature sensor input could causes an incorrect initial TCC apply

Engine Speed

1. The ignition module provides engine speed data the TCM.
2. The TCM uses engine speed information for controlling wide open throttle shifts and the TCC PWM solenoid duty cycle.

Stoplamp Switch

1. Provides brake apply information to the TCM for controlling TCC apply and release.
2. An incorrect TCC stoplamp switch input could causes an incorrect TCC apply or release.

Line Pressure Control Valve

The line pressure control valve sets the general pressure level in the valve body. When gearshifts are not taking place, the line pressure varies between 2 levels, depending on the turbine torque. Line pressure increase linearly by time. But it has a limit point. When pressure reaches that point, excess oil pressure drains back into the oil sump.

Reduction Valve

The reduction valve reduces the line pressure with which the downstream solenoid valves and pressure control solenoid valves (EDS) are supplied. This makes it possible to use smaller solenoid valves. The line pressure comes from the oil pump and flows to the reduction valve. The inlet port to the reduction valve will be blocked and line pressure will be maintained at the appropriate level.

Solenoid Valve 1, 2

Solenoid Valve 1 controls the line pressure (high and low) to the clutch valves. Solenoid Valve 1 is either ON or OFF. When the solenoid is turned ON the line pressure will be low (87 - 116 psi [6 - 8 bar]). When the solenoid is turned OFF the line pressure will be high (232 - 261 psi [16 - 18 bar]).

Solenoid 2 controls the fluid flow to clutch valve E or the TCC clutch valve. When solenoid 2 is ON fluid is directed to the TCC pressure valve and if the solenoid is switched OFF fluid will flow to the inlet at clutch valve E.

The TCM monitors numerous inputs to determine the appropriate solenoid state combination and transaxle gear for the vehicle operating conditions.

In Park and Neutral solenoid valve 1 is ON. So line pressure flows to the safety valve and the line pressure control valve via the solenoid valve.

Clutch B Engaged

In Park and Neutral solenoid valves 1 and 2 are both ON. Pressure control solenoids (EDS) 4 and 6 are also turned ON.

When EDS 6 is ON, the fluid supplied from the reduction valve flows to the safety valve, clutch valve B and holding valve B. The oil that is supplied to the inlet port of the clutch valve presses on the valve spool. Line pressure then flows to the holding valve and check ball, engaging clutch B.

Lock-up Clutch (TCC)

Solenoid 2 is turned ON and the line pressure control valves spool will be depressed. Fluid will now flow through the torque converter pressure valve.

As a result, the oil pressure behind the converter lock-up clutch piston and in the turbine zone is equal. The direction of flow is through the turbine shaft and through the space behind the piston, to the turbine chamber.

The line pressure, which is supplied by the oil pump, is directed to clutch B via the manual valve. The position of the check ball will change allowing direct pressure to clutch B.

Brake D Engaged

The line pressure, which engaged clutch B, is also supplied to clutch valve D.

In Reverse, solenoid 1 is switched ON and EDS 4 is switched OFF. This will cause the fluid supplied to the reduction valve to flow to clutch valve D via the EDS 4.

The spool of clutch valve D will be depressed allowing fluid to pass to holding valve D.

Solenoid 2 is turned ON and the line pressure control valve spool will be depressed. Fluid will now flow through the torque converter pressure valve.

As a result, the oil pressure behind the converter lock-up clutch piston and in the turbine zone is equal. The direction of flow is through the turbine shaft and through the space behind the piston, to the turbine chamber.

In Park and Neutral solenoid valves 1 and 2 are both ON. Pressure control solenoids (EDS) 4 and 6 are also turned ON.

When EDS 6 is ON, the fluid supplied from the reduction valve flows to the safety valve, clutch valve B and holding valve B. The oil that is supplied to the inlet port of the clutch valve presses on the valve spool. Line pressure then flows to the holding valve and check ball, engaging clutch B.

Clutch F Engaged

EDS 5 will be switched ON. The line pressure, which passed through the reduction valve, will flow to the holding valve and the clutch valve inlet. As a result the valve spool is depressed.

Solenoid 2 is turned ON and the line pressure control valve spool will be depressed. Fluid will now flow through the torque converter pressure valve.

As a result, the oil pressure behind the converter lock-up clutch piston and in the turbine zone is equal. The direction of flow is through the turbine shaft and through the space behind the piston, to the turbine chamber.

Clutch E Engaged

Solenoid 2 will be switched OFF. Line pressure, which is supplied by the reduction valve, flows to the inlet port of clutch valve E. Fluid will then pass through the clutch valve and clutch E will engage.

EDS 5 will be switched ON. The line pressure, which passed through the reduction valve, will flow to the holding valve and the clutch valve inlet. As a result the valve spool is depressed.

Lock-up Clutch

Solenoid valve 2 is turned ON and the line pressure control valve spool will be depressed. Fluid will now flow through the torque converter pressure valve.

As a result, the oil pressure behind the converter lock-up clutch piston and in the turbine zone is equal. The direction of flow is through the turbine shaft and through the space behind the piston, to the turbine chamber.

In Park and Neutral solenoid valves 1 and 2 are both ON. Pressure control solenoids (EDS) 4 and 6 are also turned ON.

When EDS 6 is ON, the fluid supplied from the reduction valve flows to the safety valve, clutch valve B and holding valve B. The oil that is supplied to the inlet port of the clutch valve presses on the valve spool. Line pressure then flows to the holding valve and check ball, engaging clutch B.

Solenoid valve 2 is turned ON and the line pressure control valve spool will be depressed. Fluid will now flow through the torque converter pressure valve.

As a result, the oil pressure behind the converter lock-up clutch piston and in the turbine zone is equal. The direction of flow is through the turbine shaft and through the space behind the piston, to the turbine chamber.

Scheme 149

In Drive 4, transaxle drive is via the input shaft and clutches E and C. The elements of this transaxle function are as follows

1. Clutch E is engaged to drive the rear planetary gear carrier.
2. The rear planetary gear carrier drives the rear ring gear.
3. The rear ring gear carrier drives the differential gear.

Solenoid 2 will be switched OFF. Line pressure, which is supplied by the reduction valve, flows to the inlet port of clutch valve E. Fluid will then pass through the clutch valve and clutch E will engage.

Clutch C Engaged

EDS 4 will be switched OFF causing the fluid level to be high. Line pressure will be directed to the safety valve, clutch valve D and holding valve D. Clutch valve C and holding valve C will engage as pressure flows through the safety valve.

Solenoid valve 2 is turned ON and the line pressure control valve spool will be depressed. Fluid will now flow through the torque converter pressure valve.

As a result, the oil pressure behind the converter lock-up clutch piston and in the turbine zone is equal. The direction of flow is through the turbine shaft and through the space behind the piston, to the turbine chamber.

Scheme 150

In Drive 4, transaxle drive is via the input shaft and clutches E and C. The elements of this transaxle function are as follows

1. Clutch E is engaged to drive the rear planetary gear carrier.
2. The rear planetary gear carrier drives the rear ring gear.
3. The rear ring gear carrier drives the differential gear.

Solenoid 2 will be switched OFF. Line pressure, which is supplied by the reduction valve, flows to the inlet port of clutch valve E. Fluid will then pass through the clutch valve and clutch E will engage.

EDS 4 will be switched OFF causing the fluid level to be high. Line pressure will be directed to the safety valve, clutch valve D and holding valve D. Clutch valve C and holding valve C will engage as pressure flows through the safety valve.

Scheme 151

In Drive 3, transaxle drive is via the input shaft to clutches B and E. The elements of this transaxle function are as follows

1. Clutches B and E are engaged to drive the rear sun gear and rear planetary gear carrier clockwise.
2. The clockwise rotation of the rear sun gear and rear planetary gear carrier will cause the front planetary gear to rotate in the same direction.

In Park and Neutral solenoid valves 1 and 2 are both ON. Pressure control solenoids (EDS) 4 and 6 are also turned ON.

When EDS 6 is ON, the fluid supplied from the reduction valve flows to the safety valve, clutch valve B and holding valve B. The oil that is supplied to the inlet port of the clutch valve presses on the valve spool. Line pressure then flows to the holding valve and check ball, engaging clutch B.

Basic Knowledge Required

You must be familiar with some basic electronics to use this article. They will help you to follow diagnostic procedures.

Do not, under any circumstances, attempt to diagnose a transaxle problem without this basic knowledge.

Diagnostic test probes are now available that allow you to probe individual wires without leaving the wire open to the environment. These probe devices are inexpensive and easy to install, and they permanently seal the wire from corrosion.

General Method

1. Verify that the leak is transaxle fluid.
2. Thoroughly clean the suspected leak area.
3. Drive the vehicle for approximately 25 km (15 miles) or until the transaxle reaches normal operating temperature (88 °C [190 °F]).
4. Park the vehicle over clean paper or cardboard.
5. Turn the engine OFF and look for fluid spots on the paper.
6. Make the necessary repairs to correct the leak.

Powder Method

1. Thoroughly clean the suspected leak area.
2. Apply an aerosol type powder (foot powder) to the suspected leak area.
3. Drive the vehicle for approximately 25 km (15 miles) or until the transaxle reaches normal operating temperature (88 °C [190 °F]).
4. Turn the engine OFF.
5. Inspect the suspected leak area and trace the leak path through the powder to find the source of the leak.
6. Make the necessary repairs.

Dye and Black Light Method

1. Add dye to the transaxle though the transaxle fluid filler plug. Follow the manufacturer's recommendation for the amount of dye to be used.
2. Use the black light to find the fluid leak.
3. Make the necessary repairs.

Composition Plates

Dry the plate and inspect the plates for the following conditions

1. Pitting
2. Flaking
3. Wear
4. Glazing
5. Cracking
6. Charring

Chips or metal particles embedded in the lining.

Replace a composition plate which shows any of these conditions.

Steel Plates

Wipe the plates dry and check the plates for heat discoloration. If the surfaces are smooth, even if colorsmear is indicated, you can reuse the plate. If the plate is discolored with hot spots or if the surface is scuffed, replace the plate.

Causes of Burned Clutch Plates

The following conditions can result in a burned clutch plate

1. Incorrect usage of clutch plates.
2. Engine coolant in the transaxle fluid.
3. A cracked clutch piston.
4. Damaged or missing seals.
5. Low line pressure.
6. Valve problems. The valve body face is not flat Porosity between channels The valve bushing clips are improperly installed. The check balls are misplaced.
7. The seal rings are worn or damaged.

Engine Coolant in Transaxle

Perform the following steps if the transaxle oil cooler has developed a leak, allowing engine coolant to enter the transaxle

1. Because the coolant will attach to the seal material causing leakage, disassemble the transaxle and replace all rubber type seals.
2. Because the facing material may become separated from the steel center portion, replace the composition faced clutch plate assemblies.
3. Replace all nylon parts including washers.
4. Replace the torque converter.
5. Thoroughly clean and rebuild the transaxle, using new gaskets and oil filter.
6. Flush the cooler lines after you have properly repaired or replaced the transaxle.

Functional Check

1. Install a tachometer or scan tool.
2. Operate the vehicle unit proper operating temperature is reached.
3. Drive the vehicle at 80 - 88 km/h (50 - 55 mph) with light throttle (road load).
4. Maintaining throttle position, lightly touch the brake pedal and check for release of the TCC and a slight increase in engine speed (RPM).
5. Release the brake slowly accelerate and check for a reapply of the Lock-up clutch and a slight decrease in engine speed (RPM).

Condition A - Poor Acceleration Low Speed

The car tends to have poor acceleration from a stand still. At speeds above 50 - 55 km/h (30 - 35 mph), the car may act normal. If poor acceleration is noted, it should first be determined that the exhaust system is not blocked, and the transaxle is in 1st (First) gear when starting out.

If the engine freely accelerates to high RPM in N (Neutral), it can be assumed that the engine and exhaust system are normal. Checking for poor performance in "Drive" and "Reverse" will help determine if the stator is freewheeling at all times.

Condition B - Poor Acceleration High Speed

Engine RPM and car speed limited or restricted at high speeds. Performance when accelerating from a standstill is normal. Engine may overheat. Visual examination of the converter may reveal a blue color from overheating. If the converter has been removed, the stator roller clutch can be checked by inserting 2 fingers into the splined inner race of the roller clutch and trying to turn freely clockwise, but not turn or be very difficult to turn counter clockwise.

While TCC Is Applying or Releasing

If the shudder occurs while TCC is applying, the problem can be within the transaxle or torque converter. Something is not allowing the clutch to become fully engaged, not allowing clutch to release or is trying to release and apply the clutch at the same time. This could be caused by leaking turbine shaft seals, a restricted release orifice, a distorted clutch or housing surface due to long converter bolts or defective friction material on the TCC plate.

Shudder Occurs after TCC Has Applied

In this case, most of the time there is nothing wrong with the transaxle. As mentioned above, once the TCC has been applied, it is very unlikely that will slip. Engine problems may go unnoticed under light throttle and load, but become noticeable after TCC apply when going up a hill or accelerating, due to the mechanical coupling between engine and transaxle.

Inspect the following components to avoid misdiagnosis of TCC shudder and possibly disassembling a transaxle and/or replacing a torque converter unnecessarily

1. Spark plugs - Inspect for cracks, high resistance or broken insulator.
2. Plug wires - Lock in each end, if there is red dust (ozone) or black substance (carbon) present, then the wires are bad. Also look for a white discoloration of the wire indicating arcing during hard acceleration.
3. Distributor cap and rotor - look for broken or un-crimped parts.
4. Coil - look for black on bottom indication arcing while engine is misfiring.
5. Fuel injector - filter may be plugged.
6. Vacuum leak - engine won't get correct amount of fuel. May run rich or lean depending on where the leak is.
7. EGR valve - valve may let it too much unburnable exhaust gas and cause engine to run lean.
8. MAP sensor - like vacuum leak, engine won't get correct amount of fuel for proper engine operation.
9. Carbon on intake valves - restricts proper flow or air/fuel mixture into cylinders.
10. Flat cam - valves don't open enough to let proper fuel/air mixture into cylinders.
11. Oxygen sensor - may command engine too rich or too lean for too long.
12. Fuel pressure - may be too low.
13. Engine mounts - vibration of mounts can be multiplied by TCC engagement.
14. Axle joints - checks for vibration.
15. TPS - TCC apply and release depends on the TPS in many engines. If TPS is out of specification, TCC may remain applied during initial engine starting.
16. Cylinder balance - bad piston rings or poorly sealing valves can cause low power in a cylinder.
17. Fuel contamination - causes poor engine performance.

TCM Initialization Procedure

When one or more operations such as shown below are performed, all learned contents which are stored in TCM memory should be erased after the operations.

1. When A/T H/W is replaced in a vehicle.
2. When a used TCU is installed in other vehicle.
3. When a vehicle condition is unstable (engine RPM flare, TPS toggling and so on; at this kind of unstable conditions, mis-adaptation might be done).

1. Connect the Scan Tool with a DLC connector in a vehicle.
2. Turn ignition switch ON.
3. Turn the power on for the Scan Tool.
4. Follow the "LEARNED INITIALIZE" procedure on the Scan Tool menu. NOTE: Before pushing "Yes" Button for TCM initialization on the Scan Tool screen, make sure that the condition is as follows: Condition: Engine idle. Select lever set "P" range.

Begin with the Functional Check Procedure which provides a general outline of how to diagnose automatic transaxle. The following functional check procedure will indicate the proper path of diagnosing the transaxle by describing the basic checks and then referencing the locations of the specific checks.

1. Check the fluid level according to the Fluid Level Service Procedure.
2. Check the transaxle for fluid leaks.
3. Check if the transaxle fluid is not burnt by color and smell.
4. Ensure that the transaxle is not in Limp Home Mode (LHM).
5. Check the battery terminals and the ground connections for corrosion or looseness.
6. Check that the cooler flow is not restricted.
7. Check all electrical connections for tightness.
8. Use on-board diagnostic tool or a scan tool to see if any transaxle trouble codes have been set. Refer to the appropriate DTC Identification information and repair the vehicle as directed. After repairing the vehicle, perform the road test and verify that the code has not set again.
9. Perform the Electrical/Garage Shift Tests.
10. Perform the Road Test .
11. Inspect the oil and check for metal or other contaminants in the oil pan.

Line Pressure Check

The 4HP 16 A/T uses a trochoid type oil pump to produce hydraulic pressure, and a pressure control solenoid (solenoid 1) to control that pressure at the pressure regulator valve, after it leaves the pump. The transaxle pressure control solenoid is controlled by an electrical signal that ranges from 0 - 12 V corresponds to minimum line pressure (approx. 89.9 - 124.7 psi [6.2 - 8.6 bar]) and 0 V corresponds to a maximum line pressure (approx. 221.9 - 252.4 psi [15.3 - 17.4 bar]) in all range.

Line pressures are calculated for 2 sets of gear ranges - Drive-Park-Neutral and Reverse. This allow the transaxle line pressure to be appropriate for different pressure needs in different gear ranges

GEAR RANGES AND LINE PRESSURE SPECIFICATION

Before performing a line pressure check, verify that the pressure control solenoid is receiving the correct electrical signal from the TCM

Scheme 152

1. Install a scan tool.
2. Start the engine and set parking brake.
3. Check for a stored pressure control solenoid diagnostic trouble code and other diagnostic trouble codes.
4. Repair vehicle, if necessary. Inspect: Fluid level Manual linkage Install or Connect: Scan tool (scanner) Oil pressure gauge at line pressure port (clutch B or E ports on transaxle case)
5. Put gear selector in Park and set the parking brake.
6. Start engine and allow it to warm up at idle.
7. Access the "Solenoid 1 Control Mode" on the scanner.
8. Switching solenoid 1 ON/OFF, accelerating the engine to 2,500 rpm, and then read the line pressure at the each gear.
9. Compare data to the Drive-Park-Neutral line pressure chart below. CAUTION: Total test running time should not exceed 2 minutes, or transaxle damage could occur. CAUTION: Brake must be applied at all times to prevent unexpected vehicle motion.

If pressure readings differ greatly from the line pressure chart, refer to the Diagnosis Charts contained in this section.

The scanner is only able to control the pressure control solenoid in Park and Neutral with the vehicle stopped. This protects the clutches from extremely high or low pressures in Drive or Reverse range.

DRIVE-PARK-NEUTRAL LINE PRESSURE CHART

Upshift Procedure

With gear selector in drive (D)

1. Look at the shift speed chart contained in this section and choose a percent throttle angle of 10 or 25%.
2. Set up the scan tool to monitor throttle angle and vehicle speed.
3. Accelerate to the chosen throttle angle and hold the throttle steady.
4. As the transaxle upshifts, note the shift speed and commanded gear changes for: 2nd gear. 3rd gear. 4th gear. CAUTION: Shift speeds may vary due to slight hydraulic delays responding to electronic controls. A change from the original equipment tire size affects shift speeds. Note when TCC applies. This should occur in fourth gear. If the apply is not noticed by an RPM drop, refer to the " Torque Converter Lock-Up Clutch (TCC) Diagnosis " information contained in this article. The Lock-up clutch should not apply unless the transaxle has reached a minimum operating temperature of 8 °C (46 °F) Trans Temp and engine coolant temp of 50 °C (122 °F).
5. Repeat steps 1 - 4 using several different throttle angles.

Part Throttle Detent Downshift

At vehicle steeds of 55 - 65 km/h (34 - 40 mph) in 4th gear, quickly increase throttle angle to greater than 50%.

Verify that

1. TCC apply.
2. Transaxle downshift to 3rd gear.
3. Solenoid 1 turns ON to OFF.
4. Solenoid 2 turns OFF.

Full Throttle Detent Downshift

At vehicle speeds of 55 - 65 km/h (34 - 40 mph) in 4th gear, quickly increase throttle angle to its maximum position (100%).

Verify that

1. TCC release.
2. Transaxle downshift to 2nd gear immediately.
3. Solenoid 1 turns ON to OFF.
4. Solenoid 2 turns OFF.

Manual Downshifts

1. At vehicle speeds of 60 km/h (40 mph) in 4th gear, release accelerator pedal while moving gear selector to Manual 3rd. Observe that: Transaxle downshift to 3rd gear immediately. Engine slows vehicle down.
2. Move gear selector back to overdrive (D) and accelerate to 50 km/h (31 mph). Release the accelerator pedal and move the gear selector to Manual 1st and observe that: Transaxle downshift to 2nd gear immediately. Engine slows vehicle down. CAUTION: A Manual 1st - 3rd Gear Ratio will occur at high speeds as an upshift safety feature. Do not attempt to perform this shift.

Coasting Downshifts

1. With the gear selector in Overdrive (D), accelerate to 4th gear with TCC applied.
2. Release the accelerator pedal and lightly apply the brakes, and observe that: TCC release. Down shifts occur at speeds shown ON the shift speed chart.

Manual Gear Range Selection

Upshifts in the manual gear ranges are controlled by the shift solenoids. Perform the following tests by accelerating at 25% TP sensor increments.

Manual 3rd

1. With vehicle stopped, move the gear selector to Manual 3rd and accelerate to observe: 1 - 2 shift. 2 - 3 shift.

Manual 2nd

1. With vehicle stopped, move the gear selector to Manual 2nd and accelerate to observe: 1 - 2 shift.
2. Accelerate to 40 km/h (25 mph) and observe: 2 - 3 shift does not occur. TCC does not apply.

Manual 1st

1. With vehicle stopped, move gear selector to Manual 1st. Accelerate to 30 km/h (19 mph) and observe: No upshifts occur.

Reverse (R)

1. With vehicle stopped, move gear selector to R (Reverse) and observe: Solenoid 1 is OFF. Solenoid 2 is OFF.

Use a scan tool to see if any transaxle trouble codes have been set. Refer to DTC Identification and repair the vehicle as directed. After repairing the vehicle, perform the hoist test and verify that the code has not set again. If the transaxle is not performing well and no trouble codes have been set, there may be an intermittent condition. Check all electrical connections for damage or a loose fit. You also have to perform a snapshot test which can help catch an intermittent condition that dose not occur long enough to set a code.

You may want to read "Electronic Component Diagnosis " in this section to become familiar with transaxle conditions caused by transaxle electrical malfunction.

If no trouble codes have been set and the condition is suspected to be hydraulic, take the vehicle on a road test.

Up Shift Speed

SHIFT SPEED CHART - UP

Down Shift Speed

SHIFT SPEED CHART - DOWN

Component Resistance Chart

TRANSAXLE COMPONENT RESISTANCE CHART

Oil Leakage

Note. Careful localization of leakage points may make it possible to prevent incorrect or cost-intensive repairs.

Test Steps

1. Thoroughly clean the transaxle, engine, and surrounding area (using a steam jet, for example).
2. To locate leakage, use a suitable identifying spray or similar product.
3. Depending on the amount of leakage, take the car for a short or a longer test drive - It may prove sufficient to place the car on a hoist and run the engine at idle speed to trace the leak.
4. If possible, determine exactly which type of oil is escaping.

OIL LEAKAGE PROBLEM SYMPTOM CHART

Shift Quality

Note. The assessment of shaft quality is, to a large extent, an individual, subjective matter. Take careful note of how the customer describes the complaint and of the manner in which he or she handles the vehicle and the controls. A sudden deterioration of shift quality may also be caused by the transaxle selecting an emergency or substitute program.

Test Steps

1. Carry out the general checks described in the automatic transaxle diagnostic information.
2. Perform a test drive to answer the following questions.

In which driving situations does the shift quality complaint arise?

To which shifts does the complaint apply?

Is the complaint reproducible within a short period, or has it only occurred sporadically or on a single occasion?

1. Check the oil level and oil quality.
2. Interrogate the fault memory and read out measurement block data.

SHIFT QUALITY PROBLEM SYMPTOM CHART

Malfunction

Note. The faults dealt with here concern transaxle functions such as "traction" (forwards and reverse) and all type of shifts. Entries will not always be made in the fault memory.

Test Steps

Perform the general checks according to the automatic transaxle diagnostic procedure.

1. Test drive
2. Check oil level and quality
3. Interrogate fault memory MALFUNCTION PROBLEM SYMPTOM CHART Symptom Possible Cause Action Malfunction Defective Clutch in Transaxle It There Is Still No Drive With the TCM Disconnected This is usually due to too little oil being added or to internal leakage. Repair is not possible; if necessary, exchange transaxle. Kick Down Switch Not Functioning Properly For checking and remedial action, refer to "Emergency/Substitute Program". Kick Down Switch Not Operating Properly For checking and remedial action, refer to ENGINE GENERAL INFORMATION AND DIAGNOSIS article. Vehicle Is in Emergency Mode For checking and remedial action, refer to "Emergency/Substitute Program".

Shift Lever Does Not Move with Brake Pedal Depressed

TEST PROCEDURE - SHIFT LEVER DOES NOT MOVE WITH BRAKE PEDAL DEPRESSED

Shift Lever Can Be Moved without Brake Pedal Depressed

TEST PROCEDURE - SHIFT LEVER CAN BE MOVED WITHOUT BRAKE PEDAL DEPRESSED

Gear Position and Range Signal Chart

GEAR POSITION AND RANGE SIGNAL CHART

1. Verify that the leak is transaxle fluid.
2. Thoroughly clean the suspected leak area.
3. Operate the vehicle for about 25 km (15 miles) or until the transaxle reaches normal operating temperature, 88 °C (190 °F).
4. Park the vehicle over clean paper or cardboard.
5. Turn the engine OFF and look for fluid spots on the paper.
6. Make the necessary repairs to correct the leak.

1. Thoroughly clean the suspected leak area.
2. Apply an aerosol-type powder (foot powder) to the suspected leak area.
3. Operate the vehicle for about 25 km (15 miles) or until the transaxle reaches normal operating temperature, 88 °C (190 °F).
4. Turn the engine OFF.
5. Inspect the suspected leak area and trace the leak path through the powder to find the source of the leak.
6. Make the necessary repairs.

Case Porosity Repair

1. Thoroughly clean the area to be repaired with a cleaning solvent. Air dry the area.
2. Using instructions from the manufacturer, mix a sufficient amount of epoxy to make the repair.
3. While the transaxle case is still hot, apply the epoxy. You can use a clean, dry soldering acid brush to clean the area and also apply the epoxy cement. Make certain that the area to be repaired is fully covered.
4. Allow the epoxy cement to dry for 3 hours before starting the engine.
5. Repeat the fluid leak diagnosis procedures. Refer to Repairing Fluid Leaks .

Scheme 153

Scheme 154

Scheme 155

1. Disconnect the negative battery cable.
2. Remove the floor console. Refer to FLOOR CONSOLE REMOVAL .
3. Disconnect the electrical switch connectors.
4. Remove the shift control cable adjuster pinch nut.
5. Loosen the nut from the shift control cable mounting bracket on the shift control assembly.
6. Remove the cable from the bracket.
7. Remove the bolt holding the shift control assembly to the floor panel.
8. Remove the shift control assembly.

Scheme 156

Determining Adjusting Disc B (PB)

Tools Required

DW260-100 Clutch B/E Disc Thickness Measuring Fixture

Scheme 157

1. Using disc thickness gauge, determine thickness MB for the disc set for clutch B (without setting disc). Turning the knob of DW260-100, make sure that surface height of A (upper side tool) is same with surface height of B (lower side tool). Then measure the B disc set thickness.
2. Calculate the test dimension PB (PB = EB - MB) EB = installation space MB = B disc set thickness EXAMPLE EB = 14.37 mm MB = 11.3 mm PB = 3.07 mm
3. Find the clutch B setting disc (clutch plate) thickness. Refer to the below table. CLUTCH B SETTING DISC (CLUTCH PLATE) THICKNESS SPECIFICATION PB Clutch B Setting Disc Thickness 2.83 - 3.39 mm 1.8 mm 3.40 - 3.68 mm 2.1 mm 3.69 - 4.08 mm 2.5 mm 4.09 - 4.54 mm 3.0 mm PB is 3.07 mm so, the setting disc (clutch plate of B set) thickness is 1.8 mm.
4. Replace clutch B's setting disc. (1.8 mm)

Determining Adjusting Disc E (PE)

Tools Required

DW260-100 Clutch B/E Disc Thickness Measuring Fixture

1. Using disc thickness gauge, determine thickness ME for the disc set for clutch E (without the setting disc). Measure the E disc set thickness. Refer to Determining Adjusting Disc B (PB) .
2. Calculate the test dimension PE (PE = EE - ME) EE = installation space ME = E disc set thickness EXAMPLE EE = 23.34 mm ME = 16.70 mm PE = 6.64 mm
3. Find the clutch E setting disc (clutch plate) thickness. Refer to the below table. CLUTCH E SETTING DISC (CLUTCH PLATE) THICKNESS SPECIFICATION PB Clutch E Setting Disc Thickness 5.41 - 6.00 mm 3.9 mm 6.01 - 6.48 mm 4.4 mm 6.49 - 6.98 mm 5.0 mm PE is 6.64 mm so, the setting disc (clutch plate of E set) thickness is 5.0 mm.
4. Replace clutch E's setting disc. (5.0 mm)

Scheme 158

Scheme 159

Scheme 160

Scheme 161

Scheme 162

Scheme 163

Scheme 164

1. Remove the clutch B/E. Refer to Clutch B/E Disassembly and Assembly .
2. Remove the rear sun gear.
3. Remove the planetary gear set.
4. Remove snap ring from front ring gear.
5. Take out rear planetary gear set.
6. Remove the axial needle bearing.
7. Take out front gear set with rear ring gear, front sun gear and oil trays.
8. Take oil trays and front sun gear off the planetary gear set.
9. Installation should follow the removal procedure in the reverse order.

Determining Adjusting Disc F

1. Calculate the test dimension PF (PF = BF - MF) BF = installation space MF = disc set thickness (assume 14.50 mm) EXAMPLE BF = 18.70 mm MF = 14.50 mm PE = 4.2 mm
2. Find the disc set's thickness. Refer to the below table. BRAKE F SETTING DISC THICKNESS SPECIFICATION PB Brake F Setting Disc Thickness 3.01 - 3.19 mm 1.8 mm 3.20 - 3.48 mm 2.1 mm 3.49 - 3.88 mm 2.5 mm 3.89 - 4.08 mm 2.7 mm 4.09 - 4.30 mm 3.0 mm PE is 4.20 mm so, the setting disc (clutch plate of F set) thickness is 3.0 mm.
3. Replace clutch B's setting disc. (3.0 mm)

Scheme 165

Scheme 166

Scheme 167

Scheme 168

1. Remove the torque converter bolts.
2. Hit the torque converter housing lightly.
3. Remove the torque converter housing. Installation Notice First pre-tighten the bolts in the following order. (7, 20) - (12, 23) - (16, 4) Tighten: Tighten the bolts to 15 N.m (11 lb-ft). Then, tighten the bolts in the following order. (15, 3) - (16, 4) - (14, 5) - (13, 23) - (12, 22) - (11, 21) - (10, 20) - (9, 19) - (8, 18) - (7, 17) - (6) - (1, 2) Last, in numerical order, tighten the bolts all the way. (1 - 23) Tighten: Tighten the bolts to 23 N.m (17 lb-ft).
4. Take out the metal gasket.
5. Take out the paper gasket.
6. Remove the oil filter bolt and oil filter. Installation Notice Tighten: Tighten the oil filter bolt to 10 N.m (89 lb-in.).
7. Remove the baffle plate bolts and baffle plate. Installation Notice Tighten: Tighten the baffle plate bolts to 10 N.m (89 lb-in.).
8. Remove the line pressure measurement plug.
9. Installation should follow the removal procedure in the reverse order. Installation Notice Tighten: Tighten the line pressure measurement plug to 20 N.m (15 lb-ft).

Scheme 169

Scheme 170

Scheme 171

1. Take out the select shaft clamping sleeve.
2. Remove the shift mechanism. Shift mechanism consists of select shaft, detent disc, connecting bar, stop bush.
3. Installation should follow the removal procedure in the reverse order.

Scheme 172

Scheme 173

1. Remove the parking lock assembly. Parking lock system is consist of parking pawl, leg spring, support bolt.
2. Installation should follow the removal procedure in the reverse order.

Scheme 174

1. Remove the piston F. Refer to Brake F, Slotted Nut Disassembly and Assembly .
2. Remove the bearing plate bolts and bearing plate.
3. Installation should follow the removal procedure in the reverse order. Installation Notice Tighten: Tighten the bearing plate bolts to 27 N.m (17 lb-ft).

Adjusting Axial Play, Input Shaft

Tools Required

DW260-080 Clutch B/E Shim Setting Gauge

Incorrect axial play may cause the vibration or noise. The specification of the axial play is 0.18 - 0.42 mm.

Scheme 175

1. Clamp fixture on the input shaft so that the measuring base rests on the stator shaft.
2. Set dial gauge to 0.
3. Measure axial play by pulling and pressing on the handle. (repeat measurement)
4. Calculate the measurement values. (average) EXAMPLE M1 = 0.51 mm M2 = 0.49 mm M = (0.51 + 0.49) / 2 = 0.5 mm S (specification) = 0.18 - 0.42 mm D (adjustment value) = 0.5 mm - (0.18 - 0.42) mm So, D is 0.08 - 0.32 mm Calculate the average, so D is 0.2 mm
5. Replace shim. Disc thickness must be between 0.08 and 0.32 mm thicker. It is sensible to select one with a disc that average 0.2 mm thicker than the one that was installed.

Transaxle Gear Ratio

TRANSAXLE GEAR RATIO

Line Pressure

LINE PRESSURE CHART