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Home / DTC / P0407 — EGR Sensor B Circuit Low

P0407 — EGR Sensor B Circuit Low

Detailed page for trouble code P0407.

34,405codes
59brands
11,914generic
22,491specific
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Code

P0407

Generic P — Powertrain

EGR Sensor B Circuit Low

Brand: Generic
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the EGR Sensor B signal, reference, or ground circuit
  • Corroded, damaged or loose connector at the EGR sensor
  • Failed EGR sensor (pressure, position or DPFE type)
  • Low or missing reference voltage from PCM
  • Intermittent ECM/PCM input fault
  • Mechanical EGR valve fault or vacuum/pressure leak affecting sensor readings

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Engine may run rough at idle or have reduced power under load
  • Poor fuel economy or increased emissions
  • Possible hesitation or stumble during acceleration
  • Failed emissions test

What to check

  • Read and record freeze frame and live data (EGR Sensor B voltage/DPFE/position) with a scan tool
  • Visually inspect sensor, connector and wiring for damage, corrosion or disconnection
  • Backprobe sensor terminals: confirm reference voltage (usually ~5V), sensor signal voltage and ground integrity
  • Check continuity and resistance between sensor connector and PCM pin(s)
  • Perform wiggle test on harness while observing live data for intermittent changes
  • Compare Sensor B readings to Sensor A (if present) and to expected values

Signal parameters

  • Typical reference voltage: ~5.0 V (varies by manufacturer)
  • Expected sensor signal range: roughly 0.5–4.5 V under normal conditions (platform-dependent)
  • Low fault threshold: signal typically below ~0.2–0.3 V triggers 'circuit low' (varies by vehicle)
  • Ground continuity: near 0 ohms to chassis/PCM ground
  • Sensor resistance/open-circuit: consult vehicle-specific service data for exact ohms

Diagnostic algorithm

  1. Connect a scan tool, confirm P0407 and record freeze frame/live data for EGR Sensor B.
  2. Visually inspect connector and wiring for damage, corrosion, pin pushed out or moisture. Repair as needed.
  3. With ignition ON (engine off), backprobe connector to verify reference voltage from PCM and good ground. If reference missing, suspect PCM or open feed.
  4. Measure sensor signal voltage with key ON then with engine running and while commanding EGR (if possible). If signal remains low, proceed to wiring checks.
  5. Check continuity and resistance between sensor signal/ground/reference pins and corresponding PCM pins; repair any opens or high resistance.
  6. Perform a wiggle test on the harness while monitoring live data to find intermittent shorts/opens.
  7. If wiring and connectors are good, substitute a known-good sensor (if available) or bench-test the sensor per service manual. Replace sensor if it fails.
  8. If sensor and wiring check good, test PCM input by checking for shorts to ground or power on the input circuit. Repair or replace PCM only after exhaustive verification.
  9. After repairs, clear codes, perform functional tests and a test drive to confirm code does not return.

Likely causes

  • Damaged harness insulation and short to ground on the sensor signal
  • Corroded pins or poor connector contact causing low voltage
  • Failed EGR sensor electronics (internal short/open)
  • Blown or high-resistance ground or reference circuit between sensor and PCM
  • Vacuum hose leak or blocked EGR passage causing sensor to read low

Fault status

⚠️ Status
Stored when the PCM detects the EGR Sensor B circuit voltage is below the expected threshold (circuit low). May set MIL and store freeze-frame data.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

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Code

P0407

GWM P — Powertrain

- Exhaust Gas Recirculation Sensor B Low

Brand: GWM
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the EGR Sensor B signal, reference, or ground circuit
  • Corroded, damaged or loose connector at the EGR sensor
  • Failed EGR sensor (pressure, position or DPFE type)
  • Low or missing reference voltage from PCM
  • Intermittent ECM/PCM input fault
  • Mechanical EGR valve fault or vacuum/pressure leak affecting sensor readings

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Engine may run rough at idle or have reduced power under load
  • Poor fuel economy or increased emissions
  • Possible hesitation or stumble during acceleration
  • Failed emissions test

What to check

  • Read and record freeze frame and live data (EGR Sensor B voltage/DPFE/position) with a scan tool
  • Visually inspect sensor, connector and wiring for damage, corrosion or disconnection
  • Backprobe sensor terminals: confirm reference voltage (usually ~5V), sensor signal voltage and ground integrity
  • Check continuity and resistance between sensor connector and PCM pin(s)
  • Perform wiggle test on harness while observing live data for intermittent changes
  • Compare Sensor B readings to Sensor A (if present) and to expected values

Signal parameters

  • Typical reference voltage: ~5.0 V (varies by manufacturer)
  • Expected sensor signal range: roughly 0.5–4.5 V under normal conditions (platform-dependent)
  • Low fault threshold: signal typically below ~0.2–0.3 V triggers 'circuit low' (varies by vehicle)
  • Ground continuity: near 0 ohms to chassis/PCM ground
  • Sensor resistance/open-circuit: consult vehicle-specific service data for exact ohms

Diagnostic algorithm

  1. Connect a scan tool, confirm P0407 and record freeze frame/live data for EGR Sensor B.
  2. Visually inspect connector and wiring for damage, corrosion, pin pushed out or moisture. Repair as needed.
  3. With ignition ON (engine off), backprobe connector to verify reference voltage from PCM and good ground. If reference missing, suspect PCM or open feed.
  4. Measure sensor signal voltage with key ON then with engine running and while commanding EGR (if possible). If signal remains low, proceed to wiring checks.
  5. Check continuity and resistance between sensor signal/ground/reference pins and corresponding PCM pins; repair any opens or high resistance.
  6. Perform a wiggle test on the harness while monitoring live data to find intermittent shorts/opens.
  7. If wiring and connectors are good, substitute a known-good sensor (if available) or bench-test the sensor per service manual. Replace sensor if it fails.
  8. If sensor and wiring check good, test PCM input by checking for shorts to ground or power on the input circuit. Repair or replace PCM only after exhaustive verification.
  9. After repairs, clear codes, perform functional tests and a test drive to confirm code does not return.

Likely causes

  • Damaged harness insulation and short to ground on the sensor signal
  • Corroded pins or poor connector contact causing low voltage
  • Failed EGR sensor electronics (internal short/open)
  • Blown or high-resistance ground or reference circuit between sensor and PCM
  • Vacuum hose leak or blocked EGR passage causing sensor to read low

Fault status

⚠️ Status
Stored when the PCM detects the EGR Sensor B circuit voltage is below the expected threshold (circuit low). May set MIL and store freeze-frame data.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0400 P0401 P0403 P0405 P0406 P0408
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Code

P0407

HUMMER P — Powertrain

Exhaust Gas Recirculation Sensor B Circuit Low

Brand: HUMMER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the EGR Sensor B signal, reference, or ground circuit
  • Corroded, damaged or loose connector at the EGR sensor
  • Failed EGR sensor (pressure, position or DPFE type)
  • Low or missing reference voltage from PCM
  • Intermittent ECM/PCM input fault
  • Mechanical EGR valve fault or vacuum/pressure leak affecting sensor readings

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Engine may run rough at idle or have reduced power under load
  • Poor fuel economy or increased emissions
  • Possible hesitation or stumble during acceleration
  • Failed emissions test

What to check

  • Read and record freeze frame and live data (EGR Sensor B voltage/DPFE/position) with a scan tool
  • Visually inspect sensor, connector and wiring for damage, corrosion or disconnection
  • Backprobe sensor terminals: confirm reference voltage (usually ~5V), sensor signal voltage and ground integrity
  • Check continuity and resistance between sensor connector and PCM pin(s)
  • Perform wiggle test on harness while observing live data for intermittent changes
  • Compare Sensor B readings to Sensor A (if present) and to expected values

Signal parameters

  • Typical reference voltage: ~5.0 V (varies by manufacturer)
  • Expected sensor signal range: roughly 0.5–4.5 V under normal conditions (platform-dependent)
  • Low fault threshold: signal typically below ~0.2–0.3 V triggers 'circuit low' (varies by vehicle)
  • Ground continuity: near 0 ohms to chassis/PCM ground
  • Sensor resistance/open-circuit: consult vehicle-specific service data for exact ohms

Diagnostic algorithm

  1. Connect a scan tool, confirm P0407 and record freeze frame/live data for EGR Sensor B.
  2. Visually inspect connector and wiring for damage, corrosion, pin pushed out or moisture. Repair as needed.
  3. With ignition ON (engine off), backprobe connector to verify reference voltage from PCM and good ground. If reference missing, suspect PCM or open feed.
  4. Measure sensor signal voltage with key ON then with engine running and while commanding EGR (if possible). If signal remains low, proceed to wiring checks.
  5. Check continuity and resistance between sensor signal/ground/reference pins and corresponding PCM pins; repair any opens or high resistance.
  6. Perform a wiggle test on the harness while monitoring live data to find intermittent shorts/opens.
  7. If wiring and connectors are good, substitute a known-good sensor (if available) or bench-test the sensor per service manual. Replace sensor if it fails.
  8. If sensor and wiring check good, test PCM input by checking for shorts to ground or power on the input circuit. Repair or replace PCM only after exhaustive verification.
  9. After repairs, clear codes, perform functional tests and a test drive to confirm code does not return.

Likely causes

  • Damaged harness insulation and short to ground on the sensor signal
  • Corroded pins or poor connector contact causing low voltage
  • Failed EGR sensor electronics (internal short/open)
  • Blown or high-resistance ground or reference circuit between sensor and PCM
  • Vacuum hose leak or blocked EGR passage causing sensor to read low

Fault status

⚠️ Status
Stored when the PCM detects the EGR Sensor B circuit voltage is below the expected threshold (circuit low). May set MIL and store freeze-frame data.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0400 P0401 P0403 P0405 P0406 P0408
Repair manuals

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Code

P0407

LAND ROVER P — Powertrain

Exhaust gas recirculation sensor B low circuit

Brand: LAND ROVER
Type: P — Powertrain
AI status
Completed
ready
Completed 100%
Page language: EN

Causes

  • Open or shorted wiring in the EGR Sensor B signal, reference, or ground circuit
  • Corroded, damaged or loose connector at the EGR sensor
  • Failed EGR sensor (pressure, position or DPFE type)
  • Low or missing reference voltage from PCM
  • Intermittent ECM/PCM input fault
  • Mechanical EGR valve fault or vacuum/pressure leak affecting sensor readings

Symptoms

  • Malfunction Indicator Lamp (MIL) illuminated
  • Engine may run rough at idle or have reduced power under load
  • Poor fuel economy or increased emissions
  • Possible hesitation or stumble during acceleration
  • Failed emissions test

What to check

  • Read and record freeze frame and live data (EGR Sensor B voltage/DPFE/position) with a scan tool
  • Visually inspect sensor, connector and wiring for damage, corrosion or disconnection
  • Backprobe sensor terminals: confirm reference voltage (usually ~5V), sensor signal voltage and ground integrity
  • Check continuity and resistance between sensor connector and PCM pin(s)
  • Perform wiggle test on harness while observing live data for intermittent changes
  • Compare Sensor B readings to Sensor A (if present) and to expected values

Signal parameters

  • Typical reference voltage: ~5.0 V (varies by manufacturer)
  • Expected sensor signal range: roughly 0.5–4.5 V under normal conditions (platform-dependent)
  • Low fault threshold: signal typically below ~0.2–0.3 V triggers 'circuit low' (varies by vehicle)
  • Ground continuity: near 0 ohms to chassis/PCM ground
  • Sensor resistance/open-circuit: consult vehicle-specific service data for exact ohms

Diagnostic algorithm

  1. Connect a scan tool, confirm P0407 and record freeze frame/live data for EGR Sensor B.
  2. Visually inspect connector and wiring for damage, corrosion, pin pushed out or moisture. Repair as needed.
  3. With ignition ON (engine off), backprobe connector to verify reference voltage from PCM and good ground. If reference missing, suspect PCM or open feed.
  4. Measure sensor signal voltage with key ON then with engine running and while commanding EGR (if possible). If signal remains low, proceed to wiring checks.
  5. Check continuity and resistance between sensor signal/ground/reference pins and corresponding PCM pins; repair any opens or high resistance.
  6. Perform a wiggle test on the harness while monitoring live data to find intermittent shorts/opens.
  7. If wiring and connectors are good, substitute a known-good sensor (if available) or bench-test the sensor per service manual. Replace sensor if it fails.
  8. If sensor and wiring check good, test PCM input by checking for shorts to ground or power on the input circuit. Repair or replace PCM only after exhaustive verification.
  9. After repairs, clear codes, perform functional tests and a test drive to confirm code does not return.

Likely causes

  • Damaged harness insulation and short to ground on the sensor signal
  • Corroded pins or poor connector contact causing low voltage
  • Failed EGR sensor electronics (internal short/open)
  • Blown or high-resistance ground or reference circuit between sensor and PCM
  • Vacuum hose leak or blocked EGR passage causing sensor to read low

Fault status

⚠️ Status
Stored when the PCM detects the EGR Sensor B circuit voltage is below the expected threshold (circuit low). May set MIL and store freeze-frame data.
🟡 Repair difficulty: Medium
⏱️ Diagnostic time: 0.5-2.0 hours

Similar codes

P0400 P0401 P0403 P0405 P0406 P0408
320

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

LAND ROVER

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