Automatic Transaxle System > Automatic Transaxle System > Troubleshooting

General Description

The value of the input shaft speed should be equal to the value of the output shaft speed, when multiplied by the 2nd gear ratio, while the transaxle is engaged in the 2nd gear. For example, if the output speed is 1000 rpm and the 2nd gear ratio is 2.370, then the input speed is 2370 rpm.

DTC Description

This code is set if the value of input shaft speed is not equal to the value of the output shaft, when multiplied by the 2nd gear ratio, while the transaxle is engaged in 2nd gear. This malfunction is mainly caused by mechanical troubles such as control valve sticking or solenoid valve malfunctioning rather than an electrical issue.

DTC Detecting Condition

Item

Detecting Condition

Possible cause

DTC Strategy

•	2nd gear incorrect ratio

•

C1 clutch

•

B1 brake

•	Valve-body(C1, B1 pressure system)

•

TCU

•	Line pressure solenoid valve(SLT)

•	Shift control solenoid valve(SLC1, SLC2, SLB1)

•	S1,S2 solenoid valve

Enable Conditions

•	ATF temp. > 20°C

•	Output speed > 500rpm

•	TCU communication = normal

•

TPS >10%

•	Shift lever switch = "D" range

•	Shift gear = 2nd gear

Threshold value

•	ㅣinput speed/2st gear ratio - output speedㅣ≥200rpm

Diagnostic Time

•	More than 12 times × more than1sec

Fail Safe

•	Self learning control is inhibited

•	Locked in 3rd gear

•	Adaptive control is inhibited

Monitor Scantool Data

1.	Connect scan tool to data link connector(DLC).

2.	Engine "ON".

3.	Monitor the "ENGINE SPEED, INPUT SPEED SENSOR, OUTPUT SPEED SENSOR, GEAR POSITION" parameter on the scan tool.

Perform the "STALL TEST" with gear position "2"

Specification : 2000~2500 engine rpm

Stall test procedure in D2 and reason

Procedure

A.	Warm up the engine.

B.	After positioning the select lever in "D" or "ON" of the HOLD SW (Operate UP SHIFT in case of "SPORTS MODE"), depress the foot brake pedal fully after that, depress the accelerator pedal to the maximum. * The slippage of 2nd gear operating parts can be detected by stall test in D2.

Reason for stall test

A.	If there is no mechanical defaults in A/T, all slippages occurrs in torque converter.

B.	Therefore, engine revolution is output, but input and output speed revolution must be "zero" due to wheel's lock.

C.	If 2nd brake system(2nd gear operating part) has faults, input speed revolution will be out.

D.	If output speed revolution is output. It means that the foot brake force is not applied fully. Remeasuring is required.

Is "STALL TEST " within specification?

	▶ Go to "Signal circuit inspection" procedure.
	▶ Go to "Component inspection" procedure.

1.	Do not let anybody stand in front of or behind the vehicle while this test is being carried out.

2.	Check the A/T fluid level and temperature and the engine coolant temperature.

•	Fluid level : At the hot mark on the oil level gauge.

•	Fluid temperature : 176 °F~ 212 °F (80~100 °C).

•	Engine coolant temperature : 176 °F~ 212 °F (80~100 °C).

3.	Chock both rear wheel(left and right).

4.	Pull the parking brake lever on with the brake pedal fully depressed.

5.	The throttle should not be left fully open for more than eight second.

6.	If carrying out the stall test two or more time, move the select lever to the "N" position and run the engine at 1,000 rpm to let the A/T fluid cool down before carrying out subsequent.

Signal Circuit Inspection

1.	Connect Scantool.

2.	Engine "ON".

3.	Monitor the "INPUT & OUTPUT SPEED SENSOR" parameter on the scantool.

Accelerate the Engine speed until about 2000 rpm in the 1st gear.

Specification : INPUT SPEED - (OUTPUT SPEED × GEAR RATIO) ≤ 200 RPM

Does "INPUT & OUTPUT SPEED SENSOR" within specifications?

	▶ Go to "Component Inspection" procedure.
	▶ Check for electrical noise of circuit in INPUT & OUTPUT SPEED SENSOR or Replace INPUT & OUTPUT SPEED SENSOR. Repair as necessary and Go to "Verification of Vehicle Repair" procedure.

Component Inspection

1.	Connect Oil pressure gauge to "C1" port.

2.	Engine "ON".

3.	Drive a car with gear position 2 in "SPORTS MODE".

Compare it with reference data as below.

Specification : refer to Standard Oil Pressure Table as below

STANDARD PERSSURE
SHIFT LEVER POSITION	ENGINE STATUS	ELEMENT	Specification (Kg/cm²)
"D" RANGE	IDLE	C1 CLUTCH	3.8 ~ 4.4
"R" RANGE	IDLE	C3 CLUTCH	5.9 ~ 7.1

Is oil pressure value within specifications?

	▶ Repair AUTO TRANSAXLE(Clutch or Brake) as necessary and Go to "Verification of Vehicle Repair" procedure.
	▶ Replace AUTO TRANSAXLE (BODY CONTROL VALVE faulty) as necessary and Go to "Verification of Vehicle Repair" procedure.

NOTE)

When replacing the TCU, must perform the N position learning and the Initial learning. (refer to Troubleshooting's 'How to perform N position learning' and 'How to perform initial learning')

Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.

1.	Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode

2.	Using a scantool, Clear DTC.

3.	Operate the vehicle within DTC Enable conditions in General information.

Are you DTCs present?

	▶ Go to the applicable troubleshooting procedure.
	▶ System performing to specification at this time.