P1104
AIR FLOW CTRL V/V POS. SNSR
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
Fault status
Similar codes
P1104
Mass Air Flow Sensor Circuit Ground
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
Fault status
Similar codes
P1104
Mass or volume of air in the soil damage 2 collector absolute pressure range
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
Fault status
Similar codes
P1104
Turbocharger Wastegate Solenoid
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
Fault status
Similar codes
P1104
MAF Ground Malfunction
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
Fault status
Similar codes
P1104
Turbocharger Waste Gate Solenoid Malfunction
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
Fault status
Similar codes
P1104
Engine Torque Control Signal Circuit Malfunction
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
Fault status
Similar codes
P1104
Oxygen Sensor Bank 1 Sensor 2 Voltage Too Low/Air Leak
Causes
- Faulty AFV position sensor (internal failure or worn potentiometer)
- Open/shorted or corroded wiring or connector between sensor/actuator and ECM
- Poor ground or missing reference voltage to the sensor
- Stuck, seized or mechanically binding air flow control valve/actuator
- ECM internal fault or incorrect calibration
- Contamination, carbon buildup or vacuum leak affecting AFV movement
Symptoms
- Malfunction Indicator Lamp (MIL) illuminated
- Erratic or high/low idle; stalling at idle
- Poor throttle response, hesitation, or reduced engine power
- Surging or unstable idle speed
- Possible limp-home mode or reduced performance
What to check
- Retrieve freeze frame and live data (AFV position sensor PID) with a scan tool
- Inspect sensor and actuator connectors for corrosion, bent pins, moisture, and secure fit
- Visually inspect wiring harness for damage, rubbing, or repairs
- Backprobe sensor connector and measure signal, reference and ground voltages
- Command AFV/actuator with a bidirectional scan tool to observe movement and sensor change
- Check for vacuum leaks or intake contamination that may impede valve movement
Signal parameters
- Sensor output: typically 0–5.0 V (varies by design) — should change smoothly with valve movement
- Reference supply: stable +5 V reference (about 5.0 V ±0.25 V) at sensor connector
- Ground: low resistance to chassis ground (near 0 Ω) with connector disconnected
- At closed valve: signal often low (approx. 0.5–1.0 V); at open valve: signal higher (approx. 4.0–4.5 V) — consult vehicle service manual for exact values
- If PWM-type position sensor: duty cycle should vary smoothly from ~0% to ~100% as valve moves
Diagnostic algorithm
- Connect a scan tool, read and record PIDs, freeze frame and pending codes. Note AFV position PID and any related codes.
- Visually inspect AFV assembly, connectors and harness. Repair any obvious physical damage or corrosion.
- With ignition ON (engine off), backprobe sensor connector: verify +5 V reference, ground continuity and sensor output voltage. Compare to expected ranges.
- Operate AFV using bidirectional control (if available) while observing sensor PID and signal voltage. Confirm the sensor signal changes smoothly and corresponds to commanded positions.
- If sensor output is stuck or out of range: disconnect sensor and measure resistance (if applicable) between sensor terminals and to ground per service manual. Check for short to power or ground.
- Perform continuity and resistance checks between sensor connector and ECM connector to rule out wiring opens or shorts. Repair damaged wiring or connectors.
- Inspect AFV mechanical movement: remove actuator or intake cover if needed to confirm valve is not seized, binding, or obstructed. Clean or replace components as necessary.
- After repairs, clear codes, perform a functional test and a road test. Re-scan to ensure the code does not return and that drivability is restored.
- If wiring and sensor check good but fault persists, consider ECM input/output diagnostics or replacement per manufacturer procedures.
Likely causes
- Damaged sensor connector pins or water ingress
- Broken wire or chafed harness to ECM causing intermittent signal
- Sensor output voltage stuck at high or low (0 V, near 5 V, or open circuit)
- Actuator not moving when commanded (mechanical seizure or linkage fault)
- Loose or corroded ground at engine harness
