5A1 – 20IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
Reverse
In Reverse, transaxle drive is via the input shaft and clutch
B. The elements of this transaxle function are as follows:
S Clutch B is engaged and drives the reverse sun
gear in a clock––wise direction.
S The D band is engaged and holds the planetary
gear carrier (front & rear) stationary causing the
differential pinion to rotate clockwise.
S The differential rotates in a counterclockwise direc-
tion.
S The output shaft is driven in a counterclockwise or
reverse direction.
Control
Clutch B Engaged
The line pressure, which is supplied by the oil pump, is di-
rected 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 sup-
plied 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 re-
duction 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.
Lock–up Clutch (TCC)
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.
Lubrication/Cooling
The lubricating valve ensures that the converter is sup-
plied with cooling oil first if the pump rate is low. The lubri-
cating pressure valve in addition guarantees that the nec-
essary amount of cooling and lubricating oil is available via
the bypass duct.
The fluid, which is supplied from the torque converter,
flows to the cooler via the lubrication valve.
ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 43
DAEWOO V–121 BL4
DIAGNOSTIC INFORMATION AND
PROCEDURES DIAGNOSIS
BASIC KNOWLEDGE REQUIRED
You must be familiar with some basic electronics to use
this section of the Service Manual. They will help you to
follow diagnostic procedures.
Notice : Lack of the basic knowledge of this transaxle
when performing diagnostic procedures could result in in-
correct diagnostic performance or damage to transaxle
components.
Do not, under any circumstances, attempt to diagnose a
transaxle problem without this basic knowledge.
Notice : If a wire is probed with a sharp instrument and not
properly sealed afterward, the wire will corrode and an
open circuit will result.
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.
Special Tools
You should be able to use a Digital Volt Meter (DVM), a cir-
cuit tester, jumper wires or leads and a line pressure gauge
set.
The functional check procedure is designed to verify the
correct operation of electronic components in the trans-
axle.
This will eliminate the unnecessary removal of transaxle
components.
FUNCTIONAL CHECK PROCEDURE
Begin with the Functional Check Procedure which pro-
vides a general outline of how to diagnose automatic
transaxle. The following functional check procedure will in-
dicate the proper path of diagnosing the transaxle by de-
scribing the basic checks and then referencing the loca-
tions of the specific checks.
S Check the fluid level according to the Fluid Level
Service Procedure.
S Check the transaxle for fluid leaks.
S Check if the transaxle fluid is not burnt by color and
smell.
S Ensure that the transaxle is not in Limp Home
Mode(LHM).
S Check the battery terminals and the ground con-
nections for corrosion or looseness.
S Check that the cooler flow is not restricted.S Check all electrical connections for tightness.
S Use on–board diagnostic tool or a scan tool to see
if any transaxle trouble codes have been set. Refer
to the appropriate ”Diagnostic Trouble Code (DTC)”
information and repair the vehicle as directed. After
repairing the vehicle, perform the road test and
verify that the code has not set again.
S Perform the Electrical/Garage Shift Tests.
S Perform the Road Test Procedure in this section.
S Inspect the oil and check for metal or other contam-
inants in the oil pan.
LINE PRESSURE CHECK
PROCEDURE
The 4HP 16 A/T uses a trochoid type oil pump to produce
hydraulic pressure, and a pressure control solenoid (sole-
noid 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 to 12 volts corresponds to minimum line
pressure (approx. 89.9 to 124.7 psi (6.2 to 8.6 bar)) and
0 volt corresponds to a maximum line pressure (approx.
221.9 to 252.4 psi (15.3 to 17.4 bar)) in all range.
Line pressures are calculated for two sets of gear ranges
– Drive–Park–Neutral and Reverse. This allow the trans-
axle line pressure to be appropriate for different pressure
needs in different gear ranges:
Gear
Range
Solenoid
1RPMPressure
Drive,
ReverseOff2,500221.9~252.4psi
(15.3~17.4 bar)
On2,50017.4~269.8psi
(1.2~18.6 bar)
Neutral,
ParkOff2,500221.9~252.4psi
(15.3~17.4 bar)
On2,50089.9~269.8 psi
(6.2~18.6 bar)
Before performing a line pressure check, verify that the
pressure control solenoid is receiving the correct electrical
signal from the TCM:
1. Install a scan tool.
2. Start the engine and set parking brake.
3. Check for a stored pressure control solenoid diag-
nostic trouble code, and other diagnostic trouble
codes.
5A1 – 44IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
4. Repair vehicle, if necessary.
Inspect:
S Fluid level.
S Manual linkage.
Install or Connect:
S Scan tool (scanner)
S 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 scan-
ner.
8. Switching solenoid 1 ON/OFF, accelerating the en-
gine to 2,500rpm, and then read the line pressure
at the each gear.
9. Compare data to the Drive–Park–Neutral line pres-
sure chart below.
Notice : Total test running time should not exceed 2 min-
utes, or transaxle damage could occur.
CAUTION : Brake must be applied at all times to pre-
vent unexpected vehicle motion.
If pressure readings differ greatly from the line pressure
chart, refer to the Diagnosis Charts contained in this sec-
tion.
Notice : Clutch damage may occur.
The scanner is only able to control the pressure control so-
lenoid in Park and Neutral with the vehicle stopped.
This protects the clutches from extremely high or low pres-
sures in Drive or Reverse rang.
Gear Range
SolenoidLine
Pressure B PortE Port
Park / NeutralONLOW90~124.7 psi (6.2~8.6 bar)
OFFHIGH221.9~252.3 ps
i (15.3~17.4 bar)
ReverseONLOW90~124.7 psi (6.2~8.6 bar)
OFFHIGH221.9~252.3 psi
(15.3~17.4 bar)
DriveONLOW90~124.7 psi (6.2~8.6 bar)
OFFHIGH137.7~162.4 psi
(9.5~11.2 bar)
3ONLOW90~124.7 psi (6.2~8.6 bar)90~124.7 psi (6.2~8.6 bar)
OFFHIGH221.9~252.3 psi
(15.3~17.4 bar)137.7~162.4 psi
(9.5~11.2 bar)
2ONLOW90~124.7 psi (6.2~8.6 bar)
OFFHIGH137.7~162.4 psi
(9.5~11.2 bar)
1ONLOW90~124.7 psi (6.2~8.6 bar)
OFFHIGH221.9~252.3 psi
(15.3~17.4 bar)
ZF 4 HP 16 AUTOMATIC TRANSAXLE 5A1 – 47
DAEWOO V–121 BL4
Repairing the Fluid Leak
Once the leak point is found the source of the leak must
be determined. The following list describes the potential
causes for the leak:
S Fasteners are not torqued to specification.
S Fastener threads and fastener holes are dirty or
corroded.
S Gaskets, seals or sleeves are misarranged, dam-
aged or worn.
S Damaged, warped or scratched seal bore or gasket
surface.
S Loose or worn bearing causing excess seal or
sleeve wears.
S Case or component porosity.
S Fluid level is too high.
S Plugged vent or damaged vent tube.
S Water or coolant in fluid.
S Fluid drain back holes plugged.
ELECTRICAL/GARAGE SHIFT TEST
This preliminary test should be performed before a hoist
or road test to make sure electronic control inputs is con-
nected and operating. If the inputs are not checked before
operating the transaxle, a simple electrical condition could
be misdiagnosed as a major transaxle condition.
A scan tool provides valuable information and must be
used on the automatic transaxle for accurate diagnosis.
1. Move gear selector to P (Park) and set the parking
brake.
2. Connect scan tool to Data Link Connector (DLC)
terminal.
3. Start engine.
4. Turn the scan tool ON.
5. Verify that the appropriate signals are present.
These signals may include:
S ENGINE SPEED
S VEHICLE SPEED
S THROTTLE POSITION
S TRANSAXLE GEAR STATE
S GEAR SHIFT LEVER POSITION
S TRANSAXLE FLUID TEMPERATURE
S CLOSED THROTTLE POSITION LEARN
S OPEN THROTTLE POSITION LEARNT
S CLOSED ACCEL. PEDAL POSITION LEARNT
S OPEN ACCEL. PEDAL POSITION LEARNT
S A/C COMPRESSOR STATUS
S MODE SWITCH
S THROTTLE POSITION VOLTAGE
S GEAR SHIFT LEVER POSITION VOLTAGE
S TRANS. FLUID TEMPERATURE VOLTAGE
S A/C SWITCH
S MODE SWITCH VOLTAGE
S BATTERY VOLTAGE
6. Monitor the A/C COMPRESSOR STATUS signal
while pushing the A/C switch.S The A/C COMPRESSOR STATUS should come
ON when the A/C switch is pressed, and turns
OFF when the A/C switch is repushed.
7. Monitor the GEAR SHIFT LEVER POSITION signal
and move the gear shift control lever through all the
ranges.
S Verify that the GEAR SHIFT LEVER POSITION
value matches the gear range indicated on the
instrument panel or console.
S Gear selections should be immediate and not
harsh.
8. Move gear shift control lever to neutral and monitor
the THROTTLE POSITION signal while increasing
and decreasing engine speed with the accelerator
pedal.
S THROTTLE POSITION should increase with
engine speed.
ROAD TEST PROCEDURE
S Perform the road test using a scan tool.
S This test should be performed when traffic and road
conditions permit.
S Observe all traffic regulations.
The TCM calculates upshift points based primarily on two
inputs : throttle angle and vehicle speed. When the TCM
wants a shift to occur, an electrical signal is sent to the shift
solenoids which in turn moves the valves to perform the
upshift.
The shift speed charts reference throttle angle instead of
”min throttle” or ”wot” to make shift speed measurement
more uniform and accurate. A scan tool should be used to
monitor throttle angle. Some scan tools have been pro-
grammed to record shift point information. Check the
introduction manual to see if this test is available.
Upshift Procedure
With gear selector in drive(D)
1. Look at the shift speed chart contained in this sec-
tion 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 :
S Second gear.
S Third gear.
S Fourth gear.
Important : 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
”Lock–up Clutch Diagnosis” information contained in this
section.
5A1 – 48IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
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 to 65km/h (34 to 40mph) in Fourth
gear, quickly increase throttle angle to greater than 50%.
Verify that :
S TCC apply.
S Transaxle downshift to 3rd gear.
S Solenoid 1 turns ON to OFF.
S Solenoid 2 turns OFF.
Full Throttle Detent Downshift
At vehicle speeds of 55 to 65km/h (34 to 40mph)in Fourth
gear, quickly increase throttle angle to its maximum posi-
tion (100%)
Verify that :
S TCC release.
S Transaxle downshift to Second gear immediately.
S Solenoid 1 turns ON to OFF
S Solenoid 2 turns OFF.
Manual Downshifts
1. At vehicle speeds of 60km/h (40mph)in Fourth
gear, release accelerator pedal while moving gear
selector to Manual Third (3). Observe that :
S Transaxle downshift to Third gear immediately.
S Engine slows vehicle down.
2. Move gear selector back to overdrive(D) and accel-
erate to 31mph (50km/h). Release the accelerator
pedal and move the gear selector to Manual
First(1) and observe that :
S Transaxle downshift to second gear immediate-
ly.
S Engine slows vehicle down
Notice : A Manual First––Third 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 Fourth gear with TCC applied.
2. Release the accelerator pedal and lightly apply the
brakes, and observe that :
S TCC release.
S 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 percent TP sensor increments.
Manual Third (3)
S With vehicle stopped, move the gear selector to
Manual third(3) and accelerate to observe :
– 1–2 shift.
– 2–3 shift.
Manual Second (2)
S With vehicle stopped, move the gear selector to
Manual second(2) and accelerate to observe :
– 1–2 shift.
S Accelerate to 40km/h(25mph) and observe :
– 2–3 shift does not occur
– TCC does not apply
Manual First (1)
S With vehicle stopped, move gear selector to Manu-
al First(1). Accelerate to 30km/h(19mph) and ob-
serve :
– No upshifts occur
Reverse (R)
S With vehicle stopped, move gear selector to R(Re-
verse) 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 ”Diagnostic Trouble Codes”in this sec-
tion 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 sus-
pected to be hydraulic, take the vehicle on a road test.
TORQUE CONVERTER LOCK–UP
CLUTCH(TCC) DIAGNOSIS
To properly diagnosis the lock–up clutch(TCC) system,
perform all electrical testing first and then the hydraulic
testing.
The TCC is applied by fluid pressure which is controlled by
a solenoid Located inside the valve body. The solenoid is
energized by completing an electrical circuit through a
combination of switches and sensors.
5A1 – 116IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
RangePark/
Neutr
alRever
seD321
GearNR1st2nd3rd4th1st2nd3rd1st2nd1st
Solenoid Valve
1ONON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFF
Solenoid Valve
2ONONONOFFOFFOFFONOFFOFFONOFFON
Line Pressure
Control Sole-
noid Valve 3
(EDS 3)OFFOFFOFFONON/
OFFON/
OFFOFFONON/
OFFOFFONOFF
Line Pressure
Control Sole-
noid Valve 4
(EDS 4)ONOFFONONONOFFONONONONONON
Line Pressure
Control Sole-
noid Valve 5
(EDS 5)OFFOFFONONOFFOFFONONOFFONONON
Line Pressure
Control Sole-
noid Valve 6
(EDS 6)ONOFFONONONOFFONONONONONON
Brake BAAAAAAAA
Brake CH
Brake DH
Clutch EAAAAAA
Brake FHHHHHHH
Lock–up
ClutchA
A = Applied
H = Holding
ON = The solenoid is energized.
OFF = The solenoid is de–energized.
** = Manual Second–Third gear is only available above approximately 100 km/h (62 mph).
*** = Manual First–Second gear is only available above approximately 60 km/h (37 mph).
Note : Manual First–Third gear is also possible at high vehicle speed as a safety feature.
DIAGNOSTIC TROUBLE CODE(DTC) P0731
GEAR 1 INCORRECT RATIO
Circuit Description
The TCM uses transaxle input speed information and out-
put speed sensor to control line pressure, TCC apply and
release and transaxle shift patterns. This information is
also uses to calculate the appropriate operating gear ra-
tios and TCC slippage. Conditions for Setting the DTC.
Conditions for Setting The DTC
S Time since TCM reset is greater than 500 msec.
S Time since shift end is greater than 500 msec.S Transmission oil temperature is greater than –10°C
(14°F).
S System voltage is greater than 9 volts.
S No input speed error DTCs P0715, P0716, and
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S No gear shift active.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.
5A1 – 118IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
RangePark/
Neutr
alRever
seD321
GearNR1st2nd3rd4th1st2nd3rd1st2nd1st
Solenoid Valve
1ONON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFF
Solenoid Valve
2ONONONOFFOFFOFFONOFFOFFONOFFON
Line Pressure
Control Sole-
noid Valve 3
(EDS 3)OFFOFFOFFONON/
OFFON/
OFFOFFONON/
OFFOFFONOFF
Line Pressure
Control Sole-
noid Valve 4
(EDS 4)ONOFFONONONOFFONONONONONON
Line Pressure
Control Sole-
noid Valve 5
(EDS 5)OFFOFFONONOFFOFFONONOFFONONON
Line Pressure
Control Sole-
noid Valve 6
(EDS 6)ONOFFONONONOFFONONONONONON
Brake BAAAAAAAA
Brake CH
Brake DH
Clutch EAAAAAA
Brake FHHHHHHH
Lock–up
ClutchA
A = Applied
H = Holding
ON = The solenoid is energized.
OFF = The solenoid is de–energized.
** = Manual Second–Third gear is only available above approximately 100 km/h (62 mph).
*** = Manual First–Second gear is only available above approximately 60 km/h (37 mph).
Note : Manual First–Third gear is also possible at high vehicle speed as a safety feature.
DIAGNOSTIC TROUBLE CODE(DTC) P0732
GEAR 2 INCORRECT RATIO
Circuit Description
The TCM uses transaxle input speed information and out-
put speed sensor to control line pressure, TCC apply and
release and transaxle shift patterns. This information is
also uses to calculate the appropriate operating gear ra-
tios and TCC slippage. Conditions for Setting the DTC.
Conditions for Setting The DTC
S Time since TCM reset is greater than 500 msec.
S Time since shift end is greater than 500 msec.S Transmission oil temperature is greater than –10°C
(14°F).
S System voltage is greater than 9 volts.
S No input speed error DTCs P0715, P0716 or
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S No gear shift active.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.
5A1 – 120IZF 4 HP 16 AUTOMATIC TRANSAXLE
DAEWOO V–121 BL4
RangePark/
Neutr
alRever
seD321
GearNR1st2nd3rd4th1st2nd3rd1st2nd1st
Solenoid Valve
1ONON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFFON/
OFF
Solenoid Valve
2ONONONOFFOFFOFFONOFFOFFONOFFON
Line Pressure
Control Sole-
noid Valve 3
(EDS 3)OFFOFFOFFONON/
OFFON/
OFFOFFONON/
OFFOFFONOFF
Line Pressure
Control Sole-
noid Valve 4
(EDS 4)ONOFFONONONOFFONONONONONON
Line Pressure
Control Sole-
noid Valve 5
(EDS 5)OFFOFFONONOFFOFFONONOFFONONON
Line Pressure
Control Sole-
noid Valve 6
(EDS 6)ONOFFONONONOFFONONONONONON
Brake BAAAAAAAA
Brake CH
Brake DH
Clutch EAAAAAA
Brake FHHHHHHH
Lock–up
ClutchA
A = Applied
H = Holding
ON = The solenoid is energized.
OFF = The solenoid is de–energized.
** = Manual Second–Third gear is only available above approximately 100 km/h (62 mph).
*** = Manual First–Second gear is only available above approximately 60 km/h (37 mph).
Note : Manual First–Third gear is also possible at high vehicle speed as a safety feature.
DIAGNOSTIC TROUBLE CODE(DTC) P0733
GEAR 3 INCORRECT RATIO
Circuit Description
The TCM uses transaxle input speed information and out-
put speed sensor to control line pressure, TCC apply and
release and transaxle shift patterns. This information is
also uses to calculate the appropriate operating gear ra-
tios and TCC slippage. Conditions for Setting the DTC.
Conditions for Setting The DTC
S Time since TCM reset is greater than 500 msec.
S Time since shift end is greater than 500 msec.S Transmission oil temperature is greater than –10°C
(14°F).
S System voltage is greater than 9 volts.
S No input speed error DTCs P0715, P0716, and
P0717.
S Output speed is greater than 256 rpm.
S Input speed is greater than 400 rpm.
S No gear shift active.
Action Taken When The DTC Sets
S The Malfunction Indicator Lamp(MIL) will illuminate.