Code
P1008
RENAULT
P — Powertrain
- Camshaft position (CMP) sensor, intake, bank 1 - signal fault
Views:
UK: 7
EN: 10
RU: 6
AI status
Completed
Completed
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Causes
- Failed or intermittent intake CMP sensor (bank 1)
- Damaged, corroded or poorly seated connector at CMP sensor
- Wiring harness open, short to ground or short to voltage in CMP circuit
- Poor sensor reference power or ground (ECM power/ground issue)
- Oil contamination or debris affecting sensor operation
- Incorrect camshaft timing (worn/failed timing chain, belt or phaser)
Symptoms
- Check Engine Light (MIL) illuminated
- Rough idle, hesitation or misfire at low RPM
- Hard start or no-start condition (intermittent)
- Reduced engine performance or limp-home mode
- Poor fuel economy and unstable idle
- Possible diagnostic trouble codes related to cam/crank correlation
What to check
- Read freeze-frame and live-data with a capable scan tool; note RPM, cam/crank correlation and any concurrent codes
- Visually inspect CMP sensor connector and wiring for damage, corrosion, oil or looseness
- Backprobe sensor connector and observe signal waveform and reference voltage with engine cranking/idle using oscilloscope or scan-tool live data
- Check continuity and resistance of wiring between CMP sensor and ECM (with ignition off)
- Check sensor reference voltage and ground at the connector (key on, engine off)
- Inspect timing chain/belt and camshaft position actuators if mechanical timing fault suspected
Signal parameters
- Typical CMP sensor uses a digital (Hall-effect/variable reluctor) signal — expected square-wave or sine-wave pulsed signal synchronized to cam rotation
- Reference supply usually ~5 V (confirm with vehicle-specific data), signal swings between ~0 V and reference voltage when active
- Signal frequency and pulse pattern vary with engine speed — expect more pulses per time at higher RPM
- No signal or stuck high/low voltage indicates open circuit, short to Vb or short to ground; intermittent/noisy waveform indicates connector/wiring or sensor contamination
- For inductive sensors the AC amplitude increases with cranking speed; for Hall sensors there is a clear digital transition
Diagnostic algorithm
- Capture freeze-frame and live data, note any concurrent codes (crank sensor, cam correlation).
- Visually inspect the intake CMP sensor, connector and harness for oil, damage or corrosion; repair or clean as required.
- With ignition ON (engine off) measure reference voltage and ground at the sensor connector; verify the reference is within expected range (~5 V typical, confirm vehicle spec).
- Start engine (or crank) and observe signal with scope or scan tool live data. Look for consistent pulses and correct timing relationship to crank if available.
- If no/erratic signal, check continuity between sensor and ECM pins; check for short to battery or ground. Repair wiring as needed.
- If wiring and supply/ground are good but signal is absent or invalid, replace the CMP sensor and re-test.
- If replacing sensor does not clear fault, inspect cam timing (chain/belt/phaser) and camshaft position actuator for mechanical issues.
- If mechanical timing and wiring are confirmed good, consider ECM fault or software — consult manufacturer service information and perform ECM tests or reflash as directed.
- After repair, clear codes and perform test drive/functional checks to confirm the fault does not return and timing/engine performance is normal.
Likely causes
- CMP sensor electrical fault (failed sensor or connector)
- Wiring harness damage (chafing, pinched or shorted wires)
- Corroded/loose connector causing intermittent contact
- Oil intrusion into connector or sensor interfering with signal
- Cam timing/chain phaser problems causing out-of-sync signal
Fault status
Status
P1008 — Intake camshaft position (bank 1) signal fault: ECM detected missing, intermittent or out-of-range signal from the intake CMP sensor circuit.
Repair difficulty: Medium
Diagnostic time: 1.0-2.5 hours
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