P24C5

Code

Generic P — Powertrain

EGR Cooler Bypass Position Sensor Exceeded Learning Limit Bank 2

Brand: Generic

Type: P — Powertrain

Views: UK: 19 EN: 49 RU: 26

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Page language: EN

Causes

Failed or out-of-range EGR cooler bypass position sensor (Bank 2)
EGR bypass actuator (motor/solenoid/stepper) failure or poor response
Sticking or seized bypass valve due to carbon, soot or deposits
Damaged wiring harness, connector corrosion, poor ground, or open/short in sensor circuit
Incorrect reference voltage or signal supply from PCM (5V reference lost)
Mechanical interference or binding in linkage/valve assembly

Symptoms

Malfunction Indicator Lamp (MIL) illuminated
Reduced engine performance or limp mode during fault conditions
Rough idle, hesitation, or poor driveability
Increased emissions (higher NOx/soot) or failed emissions test
Possible reduced EGR functionality or altered regeneration behavior on diesel systems
Stored related EGR or adaptation trouble codes

What to check

Read freeze frame and full DTC list; confirm P24C5 is current and review related codes
Check live data: commanded bypass position vs actual/learned position (Bank 2) while exercising valve
Verify EGR bypass position sensor signal voltage with ignition on and while operating valve (expected change in signal as valve moves)
Inspect connector and wiring at the position sensor and actuator for damage, corrosion, loose pins, or poor ground
Visually inspect bypass valve and linkage for carbon, soot, physical damage, or foreign objects
Perform actuator function test (if available via scan tool) to confirm valve moves to commanded positions

Signal parameters

Typical sensor reference: 5.0 V reference (check for stable 5V at sensor connector)
Typical signal voltage range: approximately 0.5 V (closed) to 4.5 V (open) — exact values vary by manufacturer
Expected change in signal when commanding valve: smooth, monotonic change across range; no jumps or dropouts
Actuator drive: may be PWM from 0–100% duty or variable voltage depending on design; commanded vs measured duty should correlate
Typical sensor resistance (if potentiometer type): often 1–10 kΩ — refer to service manual for exact Ohms
If stepper/encoder type, expect pulse/position counts to change as valve is commanded (use manufacturer PIDs)

Diagnostic algorithm

Verify code and record freeze-frame data. Check for other EGR or bank-2 related codes and note symptoms.
With scan tool, monitor live PIDs: commanded bypass position, actual/learned bypass position, sensor voltage, and actuator command. Try to reproduce fault by commanding valve through full travel.
Perform a quick electrical check: ignition ON (engine off) — verify 5V reference, battery voltage supply, and ground at sensor connector.
Inspect sensor/actuator connector and wiring for damage, corrosion, or loose pins. Wiggle-test wires while watching live data for intermittent changes.
Command the actuator (via scan tool or bench test) and observe actual sensor response. If actuator does not move but receives command, suspect actuator/mechanical bind or wiring to actuator.
Remove or access bypass valve and visually inspect for carbon/soot deposits, binding, or mechanical interference. Clean or free valve if restricted and retest.

Likely causes

Position sensor failure or intermittent signal (most common)
Carbon buildup causing bypass valve to stick or bind
Connector corrosion or open/short in signal or reference wiring
Actuator failure (unable to move valve to commanded position)

Fault status

⚠️ Status

EGR cooler bypass position sensor — Bank 2 exceeded learning/adaptation limits. Sensor/actuator out of expected range or unable to reach learned positions.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5 - 3.0 hours