Code
P1492
NISSAN
P — Powertrain
EVAP Canister Purge Control Solenoid Valve Circuit
Views:
UK: 26
EN: 61
RU: 31
AI status
Completed
Completed
100%
Causes
- Open or short in purge solenoid wiring or connector
- Corroded, loose, or disconnected connector at purge solenoid
- Failed EVAP canister purge control solenoid (stuck or coil open/shorted)
- Faulty ground or blown fuse supplying the solenoid circuit
- ECM/PCM driver fault (rare)
- Blocked or collapsed purge/vacuum hoses causing abnormal circuit operation
Symptoms
- Check Engine Light (MIL) illuminated
- Possible increased evaporative emissions or failed emission test
- Whistling or hissing from purge line if valve stuck open
- Rough idle or drivability issues if purge valve stuck open during idle
- No noticeable symptom if valve fails open/closed but overall system compensates
What to check
- Read/record freeze frame and pending codes; note operating conditions when code set
- Visual inspection of purge solenoid, connector, wiring harness, and vacuum lines
- Check related fuses and ground points for corrosion or looseness
- Measure purge solenoid coil resistance at the connector (compare to spec)
- Backprobe connector with scan tool or multimeter to verify supply voltage and ground while commanding the valve
- Command purge solenoid ON/OFF with a capable scan tool and observe response
Signal parameters
- Expected supply voltage: ~12 V battery at harness feed (key ON); may be switched or fused
- Control method: PCM typically switches ground or uses a PWM/duty cycle signal to control flow
- Coil resistance (typical range): often in the ~20–60 ohm range (verify Nissan spec for model)
- When commanded ON, coil circuit should show continuity and a change in current/duty cycle; voltage at control pin will change (grounded or PWM)
Diagnostic algorithm
- Confirm code and relevant freeze frame data with scan tool; attempt to reproduce with same conditions.
- Visually inspect purge valve, connector, wiring harness and vacuum lines for damage, corrosion or disconnection.
- Check fuse(s) and ground(s) for the EVAP purge circuit; repair as needed.
- With ignition OFF, measure purge solenoid coil resistance at the connector. If open or shorted relative to spec, replace solenoid.
- Backprobe connector: with ignition ON (engine running if required by freeze frame), command the purge valve ON/OFF from the scan tool and observe voltage/ground behavior at the harness. No change or incorrect voltage indicates wiring/ECM issue.
- If wiring seems suspect, perform continuity/resistance check from solenoid connector to ECM pin. Repair any open/shorts or chafed sections.
- If wiring and connectors are good but valve does not respond, bench-test the solenoid with a fused 12 V supply to verify operation (observe valve actuation and current draw). Replace if faulty.
- After repair, clear codes, perform active test if available, and complete a drive cycle to verify the DTC does not return.
- Safety: avoid shorting pins when backprobing; use appropriate fused test leads and protective equipment.
Likely causes
- Damaged wiring harness to the purge solenoid (chafing, rodent damage)
- Corroded connector pins at the solenoid or ECM
- Defective purge solenoid coil (out of specified resistance range or intermittent)
- Blown fuse or poor ground connection serving EVAP circuit
Fault status
Status
EVAP canister purge control solenoid valve circuit — ECM detected an electrical fault (open/short/incorrect signal) in the purge valve circuit.
Repair difficulty: Medium
Diagnostic time: 0.5-2.0 hours
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