Code
P0740
Generic
P — Powertrain
Torque Converter Clutch Circuit/Open
Views:
UK: 20
EN: 25
RU: 50
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
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Code
P0740
GWM
P — Powertrain
- Malfunction in the clutch chain
Views:
UK: 1
EN: 7
RU: 11
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
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Code
P0740
HUMMER
P — Powertrain
TCC Enable Solenoid Circuit Electrical
Views:
UK: 5
EN: 15
RU: 24
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
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Code
P0740
LAND ROVER
P — Powertrain
Failure in the torque converter clutch circuit
Views:
UK: 5
EN: 13
RU: 18
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
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Repair manuals for LAND ROVER
3
Land Rover Defender 300Tdi — Workshop Manual (1996 model year)
Workshop Manual199,00 UAH
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Workshop Manual199,00 UAH
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Workshop Manual199,00 UAH
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Code
P0740
MERCEDES-BENZ
P — Powertrain
Torque Converter Clutch Circuit Malfuction
Views:
UK: 10
EN: 21
RU: 27
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
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Code
P0740
MITSUBISHI
P — Powertrain
DCC solenoid
Views:
UK: 5
EN: 20
RU: 25
AI status
Completed
Completed
100%
Causes
- Open or shorted wiring in TCC circuit
- Failed TCC solenoid (coil open/short)
- Poor or corroded connector or pin
- Blown fuse or faulty relay in transmission control power/ground
- Low or contaminated automatic transmission fluid (ATF) causing stuck valve
- Internal transmission hydraulic fault (sticking valve, damaged torque converter)
Symptoms
- Check Engine Light / MIL illuminated (P0740 set)
- Torque converter fails to lock up — higher RPMs at cruise
- Poor fuel economy, increased engine RPMs at steady speed
- Transmission slipping or harsh/erratic shifts
- Transmission or engine overheat (increased operating temp)
- Delayed or rough engagement into drive or gears
What to check
- Verify stored freeze frame and pending codes with scan tool; re-check after clearing and drive-cycle
- Monitor live data: TCC commanded state, TCC actual/pressure (if available), transmission range and speed
- Visually inspect wiring harness and connectors at transmission for damage, corrosion, or loose pins
- Check transmission fluid level and condition (color, smell, debris)
- Check fuses and relays related to transmission/TCM power and grounds
- Backprobe TCC solenoid connector: measure reference voltage, switched ground, and PWM duty when commanded
Signal parameters
- TCC control is typically a switched ground or PWM-controlled solenoid from the TCM
- Typical solenoid coil resistance range (varies by vehicle): roughly 10–40 ohms (measure and compare to spec)
- Reference supply: ~12 V (key ON) to the circuit supply pin; control often provides ground/PWM from TCM
- PWM control can vary: 0–100% duty cycle; frequency often tens to a few hundred Hz depending on manufacturer
- Expected behavior: command ON should produce a measurable change in duty/voltage and corresponding TCC engagement/pressure (verify with live data)
Diagnostic algorithm
- Connect a capable scan tool; record freeze frame and live data for TCC command and related PIDs. Note conditions when code set.
- Clear code, perform a controlled test drive to reproduce. Confirm code returns and note conditions.
- Visually inspect connectors and wiring between TCM/ECM and transmission; repair any chafing, corrosion, or loose pins.
- With ignition ON (engine off), backprobe the TCC solenoid connector. Verify reference supply (~12V) and that control lead is low/high as expected when commanded by scan tool.
- Measure solenoid coil resistance with a multimeter. Compare to manufacturer spec; an open circuit indicates failed solenoid.
- Using the scan tool, command the TCC ON/OFF and observe voltage/duty at the connector. Look for proper PWM or switching and corresponding change in engine RPM/lock-up indication.
- If wiring and connector are good but control signal is not present, check fuses/relays and ground circuits. Trace continuity to the TCM and check for shorts to power or ground.
- If electrical circuit is good and solenoid operates but code persists, check ATF level/condition and perform transmission hydraulic pressure and stall tests to confirm valve body and torque converter functionality.
- If wiring, solenoid, and hydraulics are verified, suspect TCM/ECM driver fault; consult manufacturer guidance before replacing control module.
- After repairs, clear codes and perform a full road test and re-check for stored codes. Document findings and repairs.
Likely causes
- Broken/shorted harness to TCC solenoid
- Faulty TCC solenoid coil (open circuit)
- Corroded connector or poor ground at transmission
- Low ATF or severely degraded fluid causing internal sticking
Fault status
Status
P0740 — Torque Converter Clutch Circuit/Open: control module detected open or out-of-range signal in the TCC circuit. MIL illuminated; lock-up control disabled until condition resolved.
Repair difficulty: Medium
Diagnostic time: 1.0-3.0 hours (varies by vehicle and accessibility)
Similar codes
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