B1494

Code

Other B — Body

Ignition Cylinder Sensor Ground Short

Brand: Other

Type: B — Body

Views: UK: 28 EN: 34 RU: 23

AI status

Completed

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Page language: EN

Causes

Sensor signal or reference wire shorted to chassis ground
Damaged or pinched wiring harness insulation
Corroded or bent connector terminals
Failed ignition cylinder / ignition switch position sensor (internal short)
Faulty module (ECU/BCM) driver or internal short
Blown related fuse or poor ground at module

Symptoms

Malfunction Indicator Lamp (MIL) or warning light illuminated
Intermittent or no recognition of key / no-crank or no-start conditions
Ignition switch position not detected or erratic ignition/accessory behavior
Loss of related features (immobilizer, keyless entry or ignition modules)
Possible stored communication or ignition-related codes

What to check

Read freeze frame and stored codes; note when and how code set (key position, driving/starting)
Check battery voltage (stable 12V) and related fuses
Visual inspection of ignition cylinder sensor connector and wiring for damage, corrosion, chafing or pinched wires
Wiggle test wiring while monitoring code or live data for changes
Backprobe connector to verify presence of sensor reference, signal and ground

Signal parameters

Typical reference supply: ~5 V (dependent on vehicle) present at sensor connector with ignition ON
Sensor signal: variable 0–5 V (Hall/switch) or switched ground/ground open depending on sensor type
Expected continuity: sensor ground to chassis ~0–1 Ω
Open circuit: very high resistance (kΩ range) indicates break; direct short to chassis ≈ 0 Ω
If short-to-ground present: signal or reference measures near 0 V when it should be ~5 V or varying

Diagnostic algorithm

Record all stored codes and freeze-frame data. Clear codes and attempt to re-create to confirm repeatability.
Perform a careful visual inspection of the ignition cylinder sensor connector and wiring from the sensor back toward the main harness for damage, melted insulation, corrosion, or contact with chassis/ground.
With ignition ON, backprobe the connector: verify reference voltage (typically ~5 V), sensor signal behavior when key turned, and a good ground. Note any lines reading near 0 V that should be 5 V.
If reference or signal is near 0 V, disconnect the sensor and re-measure at the harness connector. If the voltage returns to normal with the sensor disconnected, the sensor is likely shorted internally.
Check continuity from the signal/reference wire to chassis ground. A direct short (near 0 Ω) indicates wiring contact with ground; trace and repair the shorted section.
If no short is found in wiring and the harness connector is good, substitute a known-good ignition cylinder sensor or inspect/replace the sensor.
If sensor replacement does not clear the fault, inspect module grounds and related modules (ECU/BCM). Use a schematic to check for shorts within the module or shared circuits.
After repairs, clear codes and retest through several key cycles and a road test if applicable to confirm repair. Re-scan for pending codes.

Likely causes

Wiring harness damaged where it contacts chassis or a bracket (short-to-ground)
Corroded or loose connector/terminal at the ignition cylinder sensor
Failed ignition cylinder position sensor

Fault status

⚠️ Status

Control module detected ignition cylinder sensor circuit shorted to ground. Functions relying on ignition position may be disabled; further diagnosis of wiring and sensor required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours