Code
P0746
Generic
P — Powertrain
Pressure Control Solenoid A Performance/Stuck Off
Views:
UK: 25
EN: 37
RU: 32
AI status
Completed
Completed
100%
Causes
- Failed/shorted/open TCC pressure control solenoid A
- Wiring: open, short to ground or battery, poor pin connection or corrosion at solenoid connector
- Faulty PCM/TCM driver or ground
- Low, dirty, or incorrect transmission fluid
- Clogged filter or internal valve body passage (sticking valve)
- Internal transmission or torque converter mechanical failure (TCC stuck, leakage)
Symptoms
- Check Engine/MIL illuminated (P0746 stored)
- Torque converter lockup not available (TCC does not engage) or intermittent lockup
- Poor fuel economy and increased engine RPM at cruising speeds
- Transmission slipping or harsh shifts during TCC apply/release
- Erratic shifting, limp-in mode, or reduced engine power in some vehicles
- Possible transmission overheating if problem is prolonged
What to check
- Read and record freeze-frame data and pending codes with a capable scan tool
- Inspect transmission fluid level, condition and smell (burnt fluid indicates internal damage)
- Visually inspect solenoid connector and wiring for damage, corrosion, pin fit and secure routing
- Check for related codes that may indicate wiring, PCM, or hydraulic faults
- Measure solenoid resistance (ohms) against specification (manufacturer data) and for intermittent values
- Backprobe connector and command the solenoid with a scan tool while observing voltage, ground and duty cycle
Signal parameters
- Typical control: PWM duty cycle from 0% (off) to near 100% (maximum apply) — depends on manufacturer
- Supply voltage: ~12 V when key on; solenoid driver switches to ground or PWM from PCM/TCM
- Solenoid resistance: commonly in the low- to mid-Ohm to low-10s Ohm range (consult vehicle spec)
- Common PWM frequency range: tens to a few hundred Hz (manufacturer dependent)
- Expected live-data response: commanded duty should change apply pressure/line pressure; monitored pressure or TCC feedback should follow command within seconds
Diagnostic algorithm
- Verify the code, record freeze-frame and related codes. Do not replace parts before verification.
- Check transmission fluid level and condition; correct level and replace fluid/filter if severely contaminated.
- Perform visual inspection of wiring and connector at Solenoid A; repair damaged wiring/connectors.
- With a DVOM, measure solenoid resistance and compare to spec. Replace solenoid if open or out-of-range.
- Backprobe connector and with a scan tool, command the solenoid on/off while observing voltage, ground and duty cycle. Confirm driver output from PCM/TCM and proper power supply to the solenoid.
- Check for shorts to ground or battery and continuity between solenoid connector and PCM/TCM. Repair any harness faults.
- If electrical tests are good but solenoid does not control pressure, remove valve body or solenoid (per shop manual) to inspect for contamination, sticking valves or internal wear; clean or replace as required.
- Verify line/charge pressure and TCC apply pressure when commanding solenoid; compare to specs. Low pressure may indicate pump or internal leakage issues.
- If all hydraulic and electrical checks pass, consider replacement of solenoid assembly or valve body. If replacement does not clear the issue, evaluate PCM/TCM driver output and consider module testing/replacement as a last resort.
- Clear codes and perform a road test with live-data monitoring to confirm repair; re-scan to ensure code does not return.
Likely causes
- Solenoid electrical fault (open/short/intermittent)
- Contaminated/low transmission fluid causing solenoid or valve sticking
- Connector pin corrosion or broken wire to solenoid
- Failed valve body or stuck apply/release valve
- PCM/TCM driver failure (less common)
Fault status
Status
P0746 — Pressure Control/Torque Converter Clutch Solenoid A Performance or Stuck Off. PCM detected solenoid not producing expected pressure or not responding to commands. MIL on.
Repair difficulty: Medium
Diagnostic time: 1-4 hours
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Code
P0746
GWM
P — Powertrain
- The pressure solenoid is not adjusted correctly
Views:
UK: 1
EN: 4
RU: 6
AI status
Completed
Completed
100%
Causes
- Failed/shorted/open TCC pressure control solenoid A
- Wiring: open, short to ground or battery, poor pin connection or corrosion at solenoid connector
- Faulty PCM/TCM driver or ground
- Low, dirty, or incorrect transmission fluid
- Clogged filter or internal valve body passage (sticking valve)
- Internal transmission or torque converter mechanical failure (TCC stuck, leakage)
Symptoms
- Check Engine/MIL illuminated (P0746 stored)
- Torque converter lockup not available (TCC does not engage) or intermittent lockup
- Poor fuel economy and increased engine RPM at cruising speeds
- Transmission slipping or harsh shifts during TCC apply/release
- Erratic shifting, limp-in mode, or reduced engine power in some vehicles
- Possible transmission overheating if problem is prolonged
What to check
- Read and record freeze-frame data and pending codes with a capable scan tool
- Inspect transmission fluid level, condition and smell (burnt fluid indicates internal damage)
- Visually inspect solenoid connector and wiring for damage, corrosion, pin fit and secure routing
- Check for related codes that may indicate wiring, PCM, or hydraulic faults
- Measure solenoid resistance (ohms) against specification (manufacturer data) and for intermittent values
- Backprobe connector and command the solenoid with a scan tool while observing voltage, ground and duty cycle
Signal parameters
- Typical control: PWM duty cycle from 0% (off) to near 100% (maximum apply) — depends on manufacturer
- Supply voltage: ~12 V when key on; solenoid driver switches to ground or PWM from PCM/TCM
- Solenoid resistance: commonly in the low- to mid-Ohm to low-10s Ohm range (consult vehicle spec)
- Common PWM frequency range: tens to a few hundred Hz (manufacturer dependent)
- Expected live-data response: commanded duty should change apply pressure/line pressure; monitored pressure or TCC feedback should follow command within seconds
Diagnostic algorithm
- Verify the code, record freeze-frame and related codes. Do not replace parts before verification.
- Check transmission fluid level and condition; correct level and replace fluid/filter if severely contaminated.
- Perform visual inspection of wiring and connector at Solenoid A; repair damaged wiring/connectors.
- With a DVOM, measure solenoid resistance and compare to spec. Replace solenoid if open or out-of-range.
- Backprobe connector and with a scan tool, command the solenoid on/off while observing voltage, ground and duty cycle. Confirm driver output from PCM/TCM and proper power supply to the solenoid.
- Check for shorts to ground or battery and continuity between solenoid connector and PCM/TCM. Repair any harness faults.
- If electrical tests are good but solenoid does not control pressure, remove valve body or solenoid (per shop manual) to inspect for contamination, sticking valves or internal wear; clean or replace as required.
- Verify line/charge pressure and TCC apply pressure when commanding solenoid; compare to specs. Low pressure may indicate pump or internal leakage issues.
- If all hydraulic and electrical checks pass, consider replacement of solenoid assembly or valve body. If replacement does not clear the issue, evaluate PCM/TCM driver output and consider module testing/replacement as a last resort.
- Clear codes and perform a road test with live-data monitoring to confirm repair; re-scan to ensure code does not return.
Likely causes
- Solenoid electrical fault (open/short/intermittent)
- Contaminated/low transmission fluid causing solenoid or valve sticking
- Connector pin corrosion or broken wire to solenoid
- Failed valve body or stuck apply/release valve
- PCM/TCM driver failure (less common)
Fault status
Status
P0746 — Pressure Control/Torque Converter Clutch Solenoid A Performance or Stuck Off. PCM detected solenoid not producing expected pressure or not responding to commands. MIL on.
Repair difficulty: Medium
Diagnostic time: 1-4 hours
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Code
P0746
HUMMER
P — Powertrain
Pressure Control Solenoid Performance or Stuck Off
Views:
UK: 9
EN: 18
RU: 16
AI status
Completed
Completed
100%
Causes
- Failed/shorted/open TCC pressure control solenoid A
- Wiring: open, short to ground or battery, poor pin connection or corrosion at solenoid connector
- Faulty PCM/TCM driver or ground
- Low, dirty, or incorrect transmission fluid
- Clogged filter or internal valve body passage (sticking valve)
- Internal transmission or torque converter mechanical failure (TCC stuck, leakage)
Symptoms
- Check Engine/MIL illuminated (P0746 stored)
- Torque converter lockup not available (TCC does not engage) or intermittent lockup
- Poor fuel economy and increased engine RPM at cruising speeds
- Transmission slipping or harsh shifts during TCC apply/release
- Erratic shifting, limp-in mode, or reduced engine power in some vehicles
- Possible transmission overheating if problem is prolonged
What to check
- Read and record freeze-frame data and pending codes with a capable scan tool
- Inspect transmission fluid level, condition and smell (burnt fluid indicates internal damage)
- Visually inspect solenoid connector and wiring for damage, corrosion, pin fit and secure routing
- Check for related codes that may indicate wiring, PCM, or hydraulic faults
- Measure solenoid resistance (ohms) against specification (manufacturer data) and for intermittent values
- Backprobe connector and command the solenoid with a scan tool while observing voltage, ground and duty cycle
Signal parameters
- Typical control: PWM duty cycle from 0% (off) to near 100% (maximum apply) — depends on manufacturer
- Supply voltage: ~12 V when key on; solenoid driver switches to ground or PWM from PCM/TCM
- Solenoid resistance: commonly in the low- to mid-Ohm to low-10s Ohm range (consult vehicle spec)
- Common PWM frequency range: tens to a few hundred Hz (manufacturer dependent)
- Expected live-data response: commanded duty should change apply pressure/line pressure; monitored pressure or TCC feedback should follow command within seconds
Diagnostic algorithm
- Verify the code, record freeze-frame and related codes. Do not replace parts before verification.
- Check transmission fluid level and condition; correct level and replace fluid/filter if severely contaminated.
- Perform visual inspection of wiring and connector at Solenoid A; repair damaged wiring/connectors.
- With a DVOM, measure solenoid resistance and compare to spec. Replace solenoid if open or out-of-range.
- Backprobe connector and with a scan tool, command the solenoid on/off while observing voltage, ground and duty cycle. Confirm driver output from PCM/TCM and proper power supply to the solenoid.
- Check for shorts to ground or battery and continuity between solenoid connector and PCM/TCM. Repair any harness faults.
- If electrical tests are good but solenoid does not control pressure, remove valve body or solenoid (per shop manual) to inspect for contamination, sticking valves or internal wear; clean or replace as required.
- Verify line/charge pressure and TCC apply pressure when commanding solenoid; compare to specs. Low pressure may indicate pump or internal leakage issues.
- If all hydraulic and electrical checks pass, consider replacement of solenoid assembly or valve body. If replacement does not clear the issue, evaluate PCM/TCM driver output and consider module testing/replacement as a last resort.
- Clear codes and perform a road test with live-data monitoring to confirm repair; re-scan to ensure code does not return.
Likely causes
- Solenoid electrical fault (open/short/intermittent)
- Contaminated/low transmission fluid causing solenoid or valve sticking
- Connector pin corrosion or broken wire to solenoid
- Failed valve body or stuck apply/release valve
- PCM/TCM driver failure (less common)
Fault status
Status
P0746 — Pressure Control/Torque Converter Clutch Solenoid A Performance or Stuck Off. PCM detected solenoid not producing expected pressure or not responding to commands. MIL on.
Repair difficulty: Medium
Diagnostic time: 1-4 hours
Similar codes
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Was this AI description helpful?
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Code
P0746
MERCEDES-BENZ
P — Powertrain
Pressure Control Solenoid Performance or Stuck Off
Views:
UK: 15
EN: 28
RU: 29
AI status
Completed
Completed
100%
Causes
- Failed/shorted/open TCC pressure control solenoid A
- Wiring: open, short to ground or battery, poor pin connection or corrosion at solenoid connector
- Faulty PCM/TCM driver or ground
- Low, dirty, or incorrect transmission fluid
- Clogged filter or internal valve body passage (sticking valve)
- Internal transmission or torque converter mechanical failure (TCC stuck, leakage)
Symptoms
- Check Engine/MIL illuminated (P0746 stored)
- Torque converter lockup not available (TCC does not engage) or intermittent lockup
- Poor fuel economy and increased engine RPM at cruising speeds
- Transmission slipping or harsh shifts during TCC apply/release
- Erratic shifting, limp-in mode, or reduced engine power in some vehicles
- Possible transmission overheating if problem is prolonged
What to check
- Read and record freeze-frame data and pending codes with a capable scan tool
- Inspect transmission fluid level, condition and smell (burnt fluid indicates internal damage)
- Visually inspect solenoid connector and wiring for damage, corrosion, pin fit and secure routing
- Check for related codes that may indicate wiring, PCM, or hydraulic faults
- Measure solenoid resistance (ohms) against specification (manufacturer data) and for intermittent values
- Backprobe connector and command the solenoid with a scan tool while observing voltage, ground and duty cycle
Signal parameters
- Typical control: PWM duty cycle from 0% (off) to near 100% (maximum apply) — depends on manufacturer
- Supply voltage: ~12 V when key on; solenoid driver switches to ground or PWM from PCM/TCM
- Solenoid resistance: commonly in the low- to mid-Ohm to low-10s Ohm range (consult vehicle spec)
- Common PWM frequency range: tens to a few hundred Hz (manufacturer dependent)
- Expected live-data response: commanded duty should change apply pressure/line pressure; monitored pressure or TCC feedback should follow command within seconds
Diagnostic algorithm
- Verify the code, record freeze-frame and related codes. Do not replace parts before verification.
- Check transmission fluid level and condition; correct level and replace fluid/filter if severely contaminated.
- Perform visual inspection of wiring and connector at Solenoid A; repair damaged wiring/connectors.
- With a DVOM, measure solenoid resistance and compare to spec. Replace solenoid if open or out-of-range.
- Backprobe connector and with a scan tool, command the solenoid on/off while observing voltage, ground and duty cycle. Confirm driver output from PCM/TCM and proper power supply to the solenoid.
- Check for shorts to ground or battery and continuity between solenoid connector and PCM/TCM. Repair any harness faults.
- If electrical tests are good but solenoid does not control pressure, remove valve body or solenoid (per shop manual) to inspect for contamination, sticking valves or internal wear; clean or replace as required.
- Verify line/charge pressure and TCC apply pressure when commanding solenoid; compare to specs. Low pressure may indicate pump or internal leakage issues.
- If all hydraulic and electrical checks pass, consider replacement of solenoid assembly or valve body. If replacement does not clear the issue, evaluate PCM/TCM driver output and consider module testing/replacement as a last resort.
- Clear codes and perform a road test with live-data monitoring to confirm repair; re-scan to ensure code does not return.
Likely causes
- Solenoid electrical fault (open/short/intermittent)
- Contaminated/low transmission fluid causing solenoid or valve sticking
- Connector pin corrosion or broken wire to solenoid
- Failed valve body or stuck apply/release valve
- PCM/TCM driver failure (less common)
Fault status
Status
P0746 — Pressure Control/Torque Converter Clutch Solenoid A Performance or Stuck Off. PCM detected solenoid not producing expected pressure or not responding to commands. MIL on.
Repair difficulty: Medium
Diagnostic time: 1-4 hours
Similar codes
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
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