101

TROUBLE CODE DIAGNOSIS

A/T
TCU DIAGNOSTIC SYSTEM OVERVIEW

M / T
NOTICE
• To prevent Transmission Control Module (TCM) damage. The ignition key must be OFF when disconnection or reconnection
the power to the TCM (for example bttery cable, TCM pigtail connector, TCM fuse, jumper cables, etc.).

T/C
When the TCU detects a system fault, a Diagnostic Trouble Code (DTC) is set in the TCU. This code is present while
the fault conditions are met and is stored as a ‘History DTC’ until cleared. Condition for setting and clearing each

CLUTCH
TCU DTC are provided in the relevant sections.
In the case where the vehicle type is certified for Eure On-Board Diagnostic (EOBD) compliance, the Engine Control
Module (ECM) provides the communication link to the EOBD scan tool to pass on any EOBD relevant codes from
the TCU. The table below contains a list of all supported DTCs and the classification of each for EOBD purposes.

AXLE
Where a type B DTC has been set in an EOBD vehicle, the response to the fault may include action by the ECM,
including the illumination of the Malfunction lndicator Lamp (MIL). Refer to Engine Control, for details on EOBD
system function, checks and fault clearing.

SP
CLEARING TROUBLE CODES
TCU DTCs should be cleared after repairs have been completed. Some diagnostic tables will tell you to clear the
codes before using the chart, which will help to find the cause of the problem more quickly. Always note the DTCs

ST’NG
present before clearing - this information may be helpful in the diagnostic process.

DIAGNOSTIC TROUBLE CODES

BRAKE
DTC Code Defective Cause and Action
P0707 Low gear position Cause: - Gear position sensor signal of the inhibitor switch is lower than
sensor input the normal value (defective gear position sensor)

A / BAG
- Specified value of gear position sensor signal: 0.87 V
Symptom: - Cannot shift to 1st, 3rd and 4th gear.
- Torque converter clucth stops from its operation.

A / CON
Action: - Check gear position sensor for short to ground.
- Check inhibitor switch and TCU connector for proper connection.
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 30 seconds.
P0708 High gear position Cause: - Gear position sensor signal of the inhibitor switch is higher
sensor input than the normal value (defective inhibitor switch)
- Specified value of inhibitor switch: 4.12 V
Symptom: - Cannot shift to 1st, 3rd and 4th gear position.
- Torque converter clucth stops from its operation.
Action: - Check gear position sensor for short to B+.
- Check inhibitor switch and TCU connector for proper connection.
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 30 seconds.

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DTC Code Defective Cause and Action

P0741 Torque converter Cause: - Torque conver clutch cannot be engaged even when solenoid
clutch cannot be valve (S7) is operated.
engaged - The rpm of engine and output shaft is not consistent with the
selected shift's gear ratio.
• Allowable slip rpm of torque converter:100 rpm
Symptom: - Torque converter clutch cannot be locked
Action: - Check solenoid valve (S7) wiring for short to ground or open circuit.
- Replace solenoicd valve (S7) if necessary.
- Check T/M connector TCU connector for their proper connection.
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 30 seconds.
P0742 Torque converter Cause: - Torque conver clutch is engaged when solenoid valve (S7) is
clutch engaged not operated.
- The rpm of engine and output shaft is not consistent with the
characteristic under the condition with torque converter not
engaged.
• Allowable slip rpm of torque converter < 50 rpm
Symptom: - Torque converter clutch is locked.
Action: - Check solenoid valve (S7) wiring for short to B+.
- Replace solenoicd valve (S7) if necessary.
- Check T/M connector TCU connector for their proper connection.
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 30 seconds.
P0710 Defective T/M oil Cause: - Oil temperature of T/M exceeds the specified value.
temperature sensor • Oil temperature sensor voltage > 4.88 V
• Oil temperature sensor voltage < 0.21 V
Symptom: - Oil temperature is fixed to 120°C
- Shifting impression is poor.
Action: - Check T/M oil temperature sensor for short or open circuit.
- Check T/M connector and TCU connector for proper connection.
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 3 seconds.
P0790 Defective W/N/P Cause: - The W/N/P mode switch's connection is intermittently discon-
mode switch nected (the input of the mode switch changes rapidly).
Symptom: - The switch is fixed to normal mode.
Action: - Check W/N/P mode switch input circuit for short or open circuit.
- Check W/N/P mode switch wiring.
- Replace W/N/P mode switch if necessary.
- Returns to the normal operation if the failure does not occur
within 3 seconds.

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DTC Code Defective Cause and Action

A/T
P1703 Abnormal engine Cause: - The engine rpm signal (CAN) is out of specified value or there is
rpm (CAN) no engine rpm signal.
• Engine rpm < 0 rpm

M / T
• Engine rpm > 7000 rpm
Symptom: - The engine rpm corresponding to the max. engine torque is
applyed to the shifting condition.
Action: - Check ECU and TCU connectors for poor contact.

T/C
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur

CLUTCH
within 3 seconds.
P1704 Abnormal output Cause: - The output shaft signal (CAN) is out of specified value or there
shaft rpm (CAN) is no output shaft signal.
• Output shaft rpm < 0 rpm

AXLE
• Output shaft rpm > 9000 rpm
- The actual vehicle speed is 0 while other signals indicate that
vehicle is moving.
Symptom: - Cannot shift down by limiting the engine rpm to prevent the

SP
engine from overrunning.
Action: - Check ECU and TCU connectors for poor contact.
- Replace TCU if necessary.

ST’NG
- Returns to the normal operation if the failure does not occur
within 3 seconds and the rpm is over 0.

BRAKE
P1708 Low TCU supply Cause: - The TCU supply voltage is low or there is no measured voltage
voltage value.
Symptom: - Cannot shift to 1st gear position.
- Cannot shift to other gear positions due to the low supply voltage.

A / BAG
- No. 6 solenoid valve (S6) stops from its operation.
Action: - Check TCU terminal for poor contact, bending or deformation.
- Replace TCU if necessary.

A / CON
- Returns to the normal operation if the failure does not occur
within 30 seconds.
P1709 High TCU supply Cause: - The TCU supply voltage is high.
voltage • TCU supply voltage > 16.5 V
Symptom: - All solenoid valves stop from their operation when high battery
voltage is detected.
- Enters into the emergency mode.
Action: - Check TCU terminal for short to B+ or short to ground.
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 30 seconds.

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DTC Code Defective Cause and Action

P1713 Defective accelera- Cause: - The accelerator pedal signal (CAN) is out of the specified value.
tor pedal signal • Accelerator pedal signal < 0 %
(CAN)
• Accelerator pedal signal > 100 %
Symptom: - Cannot shift to 4th gear position.
- Torque converter clucth stops from its operation.
- The interior default value is applied for shift determination (if the
accelerator pedal signal is defective, ECU selects the default
value and sends it and error message to TCU via CAN line).
- The accelerator pedal signal is not used for P, R, N B2.
Action: - Check ECU and TCU connectors for poor contact and their
terminals for bend or deformation.
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 30 seconds.
P1714 Defective vehicle Cause: - The vehicle coding stored in EEPROM is defective (self-test
coding when IGN ON).
Symptom: - Determines the vehicle coding value via CAN communication
or selects 0 for the coding value.
- Shifting impression is poor.
Action: - Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1715 Abnormal VPS Cause: - VPS (Variable pressure solenoid valve) is used for controlling
offset clutch and band pressure while shifting.
- The VPS offset stored in EEPROM is incorrect (self-test when
IGN ON).
• VPS offset > 120 mA
Symptom: - Shifting impression is poor.
Action: - Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1717 Defective RAM Cause: - RAM operates abnormally. (self-test when IGN ON)
Symptom: - No output signal.
- Enters into the emergency mode.
Action: - Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1718 Defective ROM Cause: - The program memory is defective (self-test when IGN ON).
- The calculated checksum value is not consistent with the stored
checksum value.
Symptom: - No output signal.
- Enters into the emergency mode.
Action: - Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

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DTC Code Defective Cause and Action

A/T
P1719 Abnormal CAN Cause: - Cannot use information necessary for TCU via CAN communication.
communication Symptom: - The default value is used for all CAN signals.
- Enters into the emergency mode.

M / T
Action: - Check ECU and TCU connectors wiring for poor contact.
- Check ECU and TCU connectors' terminals for bend or
deformation.

T/C
- Replace TCU if necessary.
- Returns to the normal operation if the failure does not occur
within 30 seconds.

CLUTCH
P1720 Defective EEPROM Cause: - EEPROM memory is defective.
- The calculated checksum value is not consistent with the stored
checksum value or the error occurs in EEPROM communication.
(self-test when IGN ON)

AXLE
Symptom: - Determines the vehicle coding value via CAN communication
or selects 0 for the coding value.
- Shifting impression is poor.
Action: - Replace TCU if necessary.

SP
- DTC disappears after turning ignition from OFF to ON.
P1722 Incorrect vehicle Cause: - Cannot detect the vehicle coding through EEPROM or CAN
model communication.

ST’NG
Symptom: - Selects 0 for the coding value.
- Enters into the emergency mode.

BRAKE
Action: - Check TCU connector and terminals for poor contact.
- DTC disappears after turning ignition from OFF to ON.
P1733 No. 1 solenoid valve Cause: - The No. 1 solenoid valve operates with the No. 2 solenoid valve
open to control the oil flow for the 1-2 shift valve.

A / BAG
- The No.1 solenoid valve internal circuit or solenoid valve wiring
is open.
- The solenoid valve connection is short to B+.

A / CON
Symptom: - The No. 1 solenoid valve is OFF.
- Enters into the emergency mode.
Action: - Check No. 1 solenoid valve wiring and connector (especially its
ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No.1 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

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DTC Code Defective Cause and Action

P1734 No. 2 solenoid valve Cause: - The No. 2 solenoid valve operates with the No. 1 solenoid valve
open to control the oil flow for the 2-3 shift valve.
- The No. 2 solenoid valve circuit is open.
- The solenoid valve connection is short to B+.
Symptom: - The No. 2 solenoid valve is OFF.
- Enters into the emergency mode.
Action: - Check No. 2 solenoid valve wiring and connector (especially,
its ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No.2 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1735 No. 3 solenoid valve Cause: - The No. 3 solenoid valve operates with the No. 4 solenoid valve
open to shift smoothly and control the shifting order.
- The No. 3 solenoid valve turns the clutch regulator valve ON
and OFF.
- The No. 3 solenoid valve circuit is open.
- The solenoid valve connection is short to B+.
Symptom: - The No. 3 solenoid valve is OFF.
- Shifting impression is poor.
Action: - Check No. 3 solenoid valve wiring and connector (especially,
its ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No.3 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

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DTC Code Defective Cause and Action

A/T
P1736 No. 4 solenoid valve Cause: - The No. 4 solenoid valve operates with the No. 3 solenoid valve
open to shift smoothly and control the shifting order.
- The No. 4 solenoid valve turns the clutch regulator valve ON and OFF.

M / T
- The No. 4 solenoid valve circuit is open.
- The solenoid valve connection is short to B+.
Symptom: - The No. 4 solenoid valve is OFF or ON.

T/C
- Shifting impression is poor.
Action: - Check No. 4 solenoid valve wiring and connector (especially,
its ground condition).

CLUTCH
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No.4 solenoid valve if necessary.

AXLE
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1737 No. 5 solenoid valve Cause: - The No. 5 solenoid valve is a variable solenoid valve to change

SP
open the pressure for shifting.
- The No. 5 solenoid valve circuit is open.
- The solenoid valve connection is short to B+.

ST’NG
Symptom: - The No. 4 solenoid valve is always OFF.
- Shifting impression is poor.
Action: - Check No. 5 solenoid valve wiring and connector (especially,

BRAKE
its ground condition).
- Specified resistance value: 3.6 ~ 5.5Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.

A / BAG
- Replace No.5 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

A / CON
P1738 No. 6 solenoid valve Cause: - The No. 6 solenoid valve is used to set the hydraulic line pres-
open sure to HIGH/LOW level.
- The No. 6 solenoid valve circuit is open.
- The solenoid valve connection is short to B+.
Symptom: - The hydraulic line pressure is high. (No. 6 solenoid valve stops
its operation)
- Cannot to shift to 1st gear position.
Action: - Check No. 6 solenoid valve wiring and connector (especially,
its ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No. 6 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

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DTC Code Defective Cause and Action

P1739 No. 7 solenoid valve Cause: - The No. 7 solenoid valve controls the operation of the torque
open converter clutch.
- The No. 7 solenoid valve circuit is open.
- The solenoid valve connection is short to B+.
Symptom: - The No. 7 solenoid valve stops its operation (OFF).
- The torque converter clutch cannot be locked.
Action: - Check No. 7 solenoid valve wiring and connector (especially,
its ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No. 7 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1741 No. 1 solenoid valve Cause: - The No. 1 solenoid valve operates with the No. 2 solenoid valve
short to control the oil flow for the 1-2 shift valve.
- The No. 1 solenoid valve circuit is short to ground.
Symptom: - The No. 1 solenoid valve is OFF.
- Enters into the emergency mode.
Action: - Check No. 1 solenoid valve wiring and connector (especially its
ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No.1 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1742 No. 2 solenoid valve Cause: - The No. 2 solenoid valve operates with the No. 1 solenoid valve
short to control the oil flow for the 2-3 shift valve.
- The No. 2 solenoid valve circuit is short to ground.
Symptom: - The No. 2 solenoid valve is OFF.
- Enters into the emergency mode.
Action: - Check No. 2 solenoid valve wiring and connector (especially its
ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No. 2 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

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DTC Code Defective Cause and Action

A/T
P1743 No. 3 solenoid valve Cause: - The No. 3 solenoid valve operates with the No. 4 solenoid valve
short to shift smoothly and control the shifting order.
- The No. 3 solenoid valve turns the clutch regulator valve ON

M / T
and OFF.
- The No. 3 solenoid valve circuit is short to ground.
Symptom: - The No. 3 solenoid valve is OFF.
- Shifting impression is poor.

T/C
Action: - Check No. 3 solenoid valve wiring and connector (especially its
ground condition).

CLUTCH
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No. 3 solenoid valve if necessary.

AXLE
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1744 No. 4 solenoid valve Cause: - The No. 4 solenoid valve operates with the No. 3 solenoid valve
short to shift smoothly and control the shifting order.

SP
- The No. 4 solenoid valve turns the clutch regulator valve ON
and OFF.
- The No. 4 solenoid valve circuit is short to ground.

ST’NG
Symptom: - The No. 4 solenoid valve is OFF.
- Shifting impression is poor.

BRAKE
Action: - Check No. 4 solenoid valve wiring and connector (especially its
ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for

A / BAG
bend or deformation.
- Replace No. 4 solenoid valve if necessary.
- Replace TCU if necessary.

A / CON
- DTC disappears after turning ignition from OFF to ON.
P1745 No. 5 solenoid valve Cause: - The No. 5 solenoid valve is a variable solenoid valve to change
short the pressure for shifting.
- The No. 5 solenoid valve circuit is short to ground.
Symptom: - The No. 4 solenoid valve is always OFF.
- Shifting impression is poor.
Action: - Check No. 5 solenoid valve wiring and connector (especially,
its ground condition).
- Specified resistance value: 3.6 ~ 5.5Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No.5 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

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DTC Code Defective Cause and Action

P1746 No. 6 solenoid valve Cause: - The No. 6 solenoid valve is used to set the hydraulic line pres-
short sure to HIGH/LOW level.
- The No. 6 solenoid valve circuit is short to ground.
Symptom: - The hydraulic line pressure is high. (No. 6 solenoid valve stops
its operation)
- Cannot to shift to 1st gear position.
Action: - Check No. 6 solenoid valve wiring and connector (especially,
its ground condition).
- Specified resistance value : 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No. 6 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.
P1747 No. 7 solenoid valve Cause: - The No. 7 solenoid valve controls the operation of the torque
short converter clutch.
- The No. 7 solenoid valve circuit is short to ground.
Symptom: - The No. 7 solenoid valve stops its operation (OFF).
- The torque converter clutch cannot be locked.
Action: - Check No. 7 solenoid valve wiring and connector (especially,
its ground condition).
- Specified resistance value: 22 ~ 30Ω
- Check TCU connector for proper connection and its terminal for
bend or deformation.
- Replace No. 7 solenoid valve if necessary.
- Replace TCU if necessary.
- DTC disappears after turning ignition from OFF to ON.

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