P044B

Code

Generic P — Powertrain

EGR Sensor C Circuit Range/Performance

Brand: Generic

Type: P — Powertrain

Views: UK: 20 EN: 40 RU: 33

AI status

Completed

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Page language: EN

Causes

Open, short, or damaged wiring between the EGR sensor C and PCM
Corroded or loose connector at the sensor or PCM
Failed EGR position/feedback sensor (Sensor C)
Bad sensor reference voltage or ground at the PCM
Carbon buildup or mechanical binding preventing EGR movement
Contamination (oil, coolant, water) affecting sensor operation

Symptoms

Check Engine MIL illuminated
Poor idle quality or stalling
Rough running, hesitation or reduced power under load
Increased exhaust emissions or failed emissions test
Possible limp-home mode depending on vehicle
Possible fuel trim abnormalities

What to check

Scan tool: read live data for EGR Sensor C voltage/position and freeze frame data
Verify related codes (EGR or reference circuit codes) and pending status
Visual inspection of EGR sensor connector and wiring for damage/corrosion
Backprobe signal, reference and ground with a multimeter or oscilloscope
Wiggle test wiring while observing live data for intermittent faults
Perform functional/commanded EGR test with scan tool (if available)

Signal parameters

Sensor type: typical EGR position sensors use a variable voltage output; expected idle range often ~0.5–4.5 V (vehicle-specific)
Reference: stable 5 V reference from PCM (verify ~5 V at sensor reference pin with key ON)
Ground: low resistance to chassis/PCM ground (near 0 Ω)
Signal behavior: voltage should change smoothly when EGR is commanded open/closed
Short to power: signal stuck near battery voltage (~12 V) or reference voltage
Short to ground: signal near 0 V or not moving when EGR commanded

Diagnostic algorithm

Retrieve freeze frame and stored data with a scan tool; note engine conditions when code set.
Verify other related DTCs (EGR control, reference circuit, ECM faults) to prioritize.
Visually inspect the EGR sensor C connector, wiring harness and nearby components for damage, heat charring, corrosion or oil contamination.
With key ON (engine OFF), backprobe the sensor connector: verify 5 V reference, good ground, and that the signal voltage is within expected range per vehicle spec.
Command EGR on/off with a scan tool while watching live signal: sensor voltage/position should move smoothly. If it does not, note whether signal is fixed, jumps, or is noisy.
Perform continuity and resistance checks on the harness between sensor and PCM pins to detect opens/shorts (including to power and ground). Repair any wiring issues.

Likely causes

Broken/frayed harness or chafed insulation near EGR valve
Corroded connector terminals at EGR sensor
Sensor C failed due to heat/oil contamination
Missing or low 5 V reference from PCM
EGR valve stuck open/closed causing out-of-range feedback
Aftermarket wiring or recent service disturbed connector

Fault status

⚠️ Status

P044B — EGR Sensor C Circuit Range/Performance: PCM detected the EGR feedback/sensor C signal is outside expected range or not changing appropriately with commanded EGR operation.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.0 - 3.0 hours