Home / DTC / P0033 — Turbocharger/Supercharger Bypass Valve A Control Circuit

P0033 — Turbocharger/Supercharger Bypass Valve A Control Circuit

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Code

P0033

Generic P — Powertrain

Turbocharger/Supercharger Bypass Valve A Control Circuit

Brand: Generic
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the bypass valve control circuit
  • Corroded or loose connector at the bypass valve solenoid
  • Failed bypass valve solenoid (stuck or electrically open/shorted)
  • Poor ground or power supply to the solenoid
  • Blocked or disconnected vacuum/boost control hose (if vacuum actuated)
  • Intermittent connection (broken wire, chafing)

Symptoms

  • Check Engine Light (MIL) illuminated
  • Reduced engine power, poor acceleration or limp mode
  • Erratic or incorrect boost pressure (overboost or underboost)
  • Hissing or unusual boost noises
  • Possible turbo surge or delayed boost response

What to check

  • Read stored freeze frame and pending codes; note conditions when code set
  • Inspect wiring and connector at bypass valve for damage, corrosion or loose pins
  • Use a scan tool to command the bypass valve and observe commanded state vs actual
  • Backprobe connector: measure supply voltage and ground while commanding actuator
  • Measure coil resistance of bypass valve solenoid (compare to spec)
  • Wiggle test wiring while monitoring signal for intermittent faults

Signal parameters

  • Typical solenoid coil resistance: commonly 20–100 ohms (varies by vehicle) — consult OEM spec
  • Control signal behavior: many systems are PCM-grounded; when commanded ON the ECM grounds the circuit (voltage at connector may drop toward 0–1 V), when OFF it is near battery voltage (~12 V) or open
  • If system is high-side switched, commanded ON may apply battery voltage to solenoid — check vehicle wiring diagram
  • Expected response: voltage/ground state changes when commanded by scan tool; no open-circuit or short-to-B+/-GND

Diagnostic algorithm

  1. Verify the code and note freeze-frame data. Clear codes and attempt to re-create under same operating conditions.
  2. Visually inspect the bypass valve, solenoid, vacuum/boost hoses, harness and connectors for damage, corrosion, rodent chew or loose pins.
  3. Using a scan tool, command the bypass valve ON/OFF while watching live data and listening for valve operation. Note any lack of response or incorrect state.
  4. With ignition ON (engine off) backprobe the solenoid connector. Check for correct supply voltage and ground reference per wiring diagram. If supply or ground missing, trace upstream (fuse, relay, harness).
  5. Measure solenoid coil resistance with connector disconnected. Compare to manufacturer spec. Infinite or very high resistance = open coil; near zero ohms = short.
  6. If coil resistance is within spec, apply appropriate bench voltage (battery voltage or per spec) briefly to the solenoid to confirm it actuates (observe valve movement or listen for click). Use caution and avoid continuous application.
  7. Perform a wiggle test on wiring/connectors while commanding the valve to check for intermittent faults. Repair any damaged wiring or corroded connectors.
  8. Inspect and test vacuum/boost hoses and the mechanical bypass/wastegate for sticking or blockage. Replace or clean as required.
  9. If wiring, connector and solenoid test good, verify ECM drive output using an oscilloscope or multimeter under dynamic conditions. If ECM drive is missing or erratic and wiring is good, consider ECM fault and consult manufacturer service information before replacement.
  10. After repairs, clear codes and perform a road test to confirm proper operation and that the code does not return.

Likely causes

  • Damaged harness or connector to bypass valve
  • Failed solenoid coil (electrical failure)
  • Short to battery or short to ground at solenoid connector
  • Stuck bypass valve or mechanical binding preventing expected feedback
  • Blown fuse or relay feeding the circuit

Fault status

⚠️ Status
P0033 — Turbocharger/Supercharger Bypass Valve A Control Circuit. The ECM detected an electrical fault in the bypass valve control circuit (open, short, or incorrect signal) or a lack of expected actuation.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

6,773

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Code

P0033

LAND ROVER P — Powertrain

Turbocharger/Supercharger Bypass Valve Control - open circuit

AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the bypass valve control circuit
  • Corroded or loose connector at the bypass valve solenoid
  • Failed bypass valve solenoid (stuck or electrically open/shorted)
  • Poor ground or power supply to the solenoid
  • Blocked or disconnected vacuum/boost control hose (if vacuum actuated)
  • Intermittent connection (broken wire, chafing)

Symptoms

  • Check Engine Light (MIL) illuminated
  • Reduced engine power, poor acceleration or limp mode
  • Erratic or incorrect boost pressure (overboost or underboost)
  • Hissing or unusual boost noises
  • Possible turbo surge or delayed boost response

What to check

  • Read stored freeze frame and pending codes; note conditions when code set
  • Inspect wiring and connector at bypass valve for damage, corrosion or loose pins
  • Use a scan tool to command the bypass valve and observe commanded state vs actual
  • Backprobe connector: measure supply voltage and ground while commanding actuator
  • Measure coil resistance of bypass valve solenoid (compare to spec)
  • Wiggle test wiring while monitoring signal for intermittent faults

Signal parameters

  • Typical solenoid coil resistance: commonly 20–100 ohms (varies by vehicle) — consult OEM spec
  • Control signal behavior: many systems are PCM-grounded; when commanded ON the ECM grounds the circuit (voltage at connector may drop toward 0–1 V), when OFF it is near battery voltage (~12 V) or open
  • If system is high-side switched, commanded ON may apply battery voltage to solenoid — check vehicle wiring diagram
  • Expected response: voltage/ground state changes when commanded by scan tool; no open-circuit or short-to-B+/-GND

Diagnostic algorithm

  1. Verify the code and note freeze-frame data. Clear codes and attempt to re-create under same operating conditions.
  2. Visually inspect the bypass valve, solenoid, vacuum/boost hoses, harness and connectors for damage, corrosion, rodent chew or loose pins.
  3. Using a scan tool, command the bypass valve ON/OFF while watching live data and listening for valve operation. Note any lack of response or incorrect state.
  4. With ignition ON (engine off) backprobe the solenoid connector. Check for correct supply voltage and ground reference per wiring diagram. If supply or ground missing, trace upstream (fuse, relay, harness).
  5. Measure solenoid coil resistance with connector disconnected. Compare to manufacturer spec. Infinite or very high resistance = open coil; near zero ohms = short.
  6. If coil resistance is within spec, apply appropriate bench voltage (battery voltage or per spec) briefly to the solenoid to confirm it actuates (observe valve movement or listen for click). Use caution and avoid continuous application.
  7. Perform a wiggle test on wiring/connectors while commanding the valve to check for intermittent faults. Repair any damaged wiring or corroded connectors.
  8. Inspect and test vacuum/boost hoses and the mechanical bypass/wastegate for sticking or blockage. Replace or clean as required.
  9. If wiring, connector and solenoid test good, verify ECM drive output using an oscilloscope or multimeter under dynamic conditions. If ECM drive is missing or erratic and wiring is good, consider ECM fault and consult manufacturer service information before replacement.
  10. After repairs, clear codes and perform a road test to confirm proper operation and that the code does not return.

Likely causes

  • Damaged harness or connector to bypass valve
  • Failed solenoid coil (electrical failure)
  • Short to battery or short to ground at solenoid connector
  • Stuck bypass valve or mechanical binding preventing expected feedback
  • Blown fuse or relay feeding the circuit

Fault status

⚠️ Status
P0033 — Turbocharger/Supercharger Bypass Valve A Control Circuit. The ECM detected an electrical fault in the bypass valve control circuit (open, short, or incorrect signal) or a lack of expected actuation.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

320

Browse 320 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

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Send to email
Code

P0033

MITSUBISHI P — Powertrain

Waste gate system

AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the bypass valve control circuit
  • Corroded or loose connector at the bypass valve solenoid
  • Failed bypass valve solenoid (stuck or electrically open/shorted)
  • Poor ground or power supply to the solenoid
  • Blocked or disconnected vacuum/boost control hose (if vacuum actuated)
  • Intermittent connection (broken wire, chafing)

Symptoms

  • Check Engine Light (MIL) illuminated
  • Reduced engine power, poor acceleration or limp mode
  • Erratic or incorrect boost pressure (overboost or underboost)
  • Hissing or unusual boost noises
  • Possible turbo surge or delayed boost response

What to check

  • Read stored freeze frame and pending codes; note conditions when code set
  • Inspect wiring and connector at bypass valve for damage, corrosion or loose pins
  • Use a scan tool to command the bypass valve and observe commanded state vs actual
  • Backprobe connector: measure supply voltage and ground while commanding actuator
  • Measure coil resistance of bypass valve solenoid (compare to spec)
  • Wiggle test wiring while monitoring signal for intermittent faults

Signal parameters

  • Typical solenoid coil resistance: commonly 20–100 ohms (varies by vehicle) — consult OEM spec
  • Control signal behavior: many systems are PCM-grounded; when commanded ON the ECM grounds the circuit (voltage at connector may drop toward 0–1 V), when OFF it is near battery voltage (~12 V) or open
  • If system is high-side switched, commanded ON may apply battery voltage to solenoid — check vehicle wiring diagram
  • Expected response: voltage/ground state changes when commanded by scan tool; no open-circuit or short-to-B+/-GND

Diagnostic algorithm

  1. Verify the code and note freeze-frame data. Clear codes and attempt to re-create under same operating conditions.
  2. Visually inspect the bypass valve, solenoid, vacuum/boost hoses, harness and connectors for damage, corrosion, rodent chew or loose pins.
  3. Using a scan tool, command the bypass valve ON/OFF while watching live data and listening for valve operation. Note any lack of response or incorrect state.
  4. With ignition ON (engine off) backprobe the solenoid connector. Check for correct supply voltage and ground reference per wiring diagram. If supply or ground missing, trace upstream (fuse, relay, harness).
  5. Measure solenoid coil resistance with connector disconnected. Compare to manufacturer spec. Infinite or very high resistance = open coil; near zero ohms = short.
  6. If coil resistance is within spec, apply appropriate bench voltage (battery voltage or per spec) briefly to the solenoid to confirm it actuates (observe valve movement or listen for click). Use caution and avoid continuous application.
  7. Perform a wiggle test on wiring/connectors while commanding the valve to check for intermittent faults. Repair any damaged wiring or corroded connectors.
  8. Inspect and test vacuum/boost hoses and the mechanical bypass/wastegate for sticking or blockage. Replace or clean as required.
  9. If wiring, connector and solenoid test good, verify ECM drive output using an oscilloscope or multimeter under dynamic conditions. If ECM drive is missing or erratic and wiring is good, consider ECM fault and consult manufacturer service information before replacement.
  10. After repairs, clear codes and perform a road test to confirm proper operation and that the code does not return.

Likely causes

  • Damaged harness or connector to bypass valve
  • Failed solenoid coil (electrical failure)
  • Short to battery or short to ground at solenoid connector
  • Stuck bypass valve or mechanical binding preventing expected feedback
  • Blown fuse or relay feeding the circuit

Fault status

⚠️ Status
P0033 — Turbocharger/Supercharger Bypass Valve A Control Circuit. The ECM detected an electrical fault in the bypass valve control circuit (open, short, or incorrect signal) or a lack of expected actuation.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.5 hours

Similar codes

406

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+100 karma for a short comment :)
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