Code
P1306
DAEWOO
P — Powertrain
PHASE SNSR - LOW INPUT
Views:
UK: 16
EN: 31
RU: 22
AI status
Completed
Completed
100%
Causes
- Damaged or corroded sensor connector or wiring (open, short to ground, or high resistance)
- Faulty phase/camshaft position sensor (failed Hall-effect or VR element)
- Low or missing sensor reference/ground (blown fuse, poor ground connection)
- Crankshaft/camshaft timing problems or damaged phaser/reluctor wheel
- Intermittent sensor contact (debris, oil contamination) or incorrect air gap
- Faulty Engine Control Module (rare)
Symptoms
- Check Engine Light (MIL) illuminated
- Hard starting, rough idle, or no-start condition
- Misfires, reduced power or engine stalling
- Poor fuel economy or hesitation on acceleration
- Stored trouble codes related to cam/crank sensors or ignition timing
What to check
- Read and record freeze-frame data and code history with a scan tool
- Visual inspection of sensor, connector, and wiring for damage, oil, or corrosion
- Verify battery and charging system voltage (stable ~12–14.5 V during cranking)
- Back-probe sensor connector to check reference voltage (usually ~5 V), ground continuity, and signal while cranking
- Measure sensor resistance (if specified) and compare to service limits
- Use an oscilloscope or lab scope to view sensor waveform at cranking and idle
Signal parameters
- Typical Hall-effect/cam (phase) sensor: 0–5 V digital square wave; low input often
- Typical variable reluctance (VR) sensor: AC sine wave; low input may be very low amplitude (
- Signal frequency/edge rate increases with engine speed; pulses per revolution depend on engine design
- Reference supply commonly 5 V (confirm with vehicle service data); expected signal toggles around reference
Diagnostic algorithm
- Retrieve live data and freeze-frame info. Note engine RPM during code set and any related codes (cam/crank/ignition).
- Perform a visual check: wiring harness, connector pins, corrosion, oil contamination, and sensor mounting/air gap.
- Verify battery voltage and main grounds. Check fuse(s) and power supply to the ECM and sensor circuit.
- Back-probe the sensor connector: confirm reference voltage (typically ~5 V), good ground, and signal while cranking/starting. If reference/ground missing, trace wiring to fuse/ECM.
- If reference/ground are present but no/low signal, measure sensor resistance per service spec (if available). Replace sensor if out of range.
- Use an oscilloscope to observe waveform during cranking and at idle. Look for missing pulses, very low amplitude, noise, or flatline.
- If waveform is irregular, inspect timing components (timing belt/chain, phaser, reluctor wheel) for mechanical issues or misalignment.
- Wiggle test wiring while monitoring signal to detect intermittent opens or shorts. Repair damaged wiring/connectors as needed.
- After repairs, clear codes and perform a road/test-crank verification. Re-scan to confirm P1306 does not return.
- If all sensor, wiring and timing components check good and code persists, consider ECM input circuit testing or replacement per factory procedure.
Likely causes
- Wiring harness damage or connector corrosion at the phase sensor
- Failed camshaft/phase sensor
- Poor sensor ground or lost 5 V reference
- Timing belt/chain or phaser damage causing no target passage at sensor
Fault status
Status
PHASE SNSR - LOW INPUT (phase/camshaft position sensor circuit low or no signal)
Repair difficulty: Medium
Diagnostic time: 1-3 hours
Your experience will help others
+100 karma for a short comment :)
Was this AI description helpful?
Your feedback helps improve AI descriptions.
👍 Like
0
👎 Dislike
0
Send to email