B1494

Code

ALFA ROMEO B — Body

Ignition cylinder sensor short to ground

Brand: ALFA ROMEO

Type: B — Body

Views: UK: 5 EN: 6 RU: 2

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Page language: EN

Damaged or chafed wiring in the steering column harness contacting chassis ground
Corroded, bent or pushed-back connector pins creating a grounded contact
Faulty ignition cylinder sensor (internal short)
Water ingress or contamination in connector or sensor
Aftermarket alarm/immobiliser or repair wiring incorrectly tied to ground
Control module input damaged (less common)

Use a scan tool to confirm B1494 and note freeze-frame/ignition position
Check for related codes (immobiliser, CAN/comm codes)
Visually inspect ignition cylinder, connector and wiring harness for damage, corrosion, or pin contact with chassis
With ignition OFF, disconnect sensor connector and inspect terminals for corrosion, bent pins, or pressed-out insulation
Backprobe the sensor connector while key is cycled to observe signal and reference voltages
Measure continuity between the sensor signal/reference wires and chassis ground (should be open/infinite)

Reference supply/ignition feed typically ~5 V (varies by vehicle) — confirm with factory data
Sensor signal expected within 0–5 V range depending on design (position or Hall effect sensor) and should not be continuously tied to 0 V (ground)
Continuity to chassis ground on signal/reference wires should be very high (open). Low resistance (
When disconnected, control module may report open circuit or different code; verify behaviour per service manual

Record DTC(s) and freeze-frame with a scan tool. Check for related immobiliser or communication codes.
Visually inspect ignition cylinder, connector and surrounding harness for damage, water or chafing. Repair obvious faults.
With connector disconnected and ignition OFF, measure resistance between each sensor wire and chassis ground. Low resistance indicates a short to ground — trace that wire.
Reconnect and backprobe the reference and signal wires. With ignition ON and while cycling key positions, verify the reference voltage (≈5 V) and that the signal is not held at 0 V.
Perform a wiggle test on the steering column wiring while monitoring the signal/scan data to try to reproduce the fault. Pay attention where the harness flexes through the column and bulkhead.
If wiring checks good, swap or bench-test the ignition cylinder sensor (if serviceable) or install a known-good sensor and re-test.
If short is located, repair harness (replace section, repair insulation, replace connector) and secure routing away from sharp edges and moving parts.
After repair, clear codes, cycle ignition and road test to confirm code does not return. If DTC persists with good wiring and sensor, suspect module input fault and consult factory procedures for module testing/replacement or software reprogramming. Note: immobiliser or key programming may be required after certain repairs.

Chafed wiring where harness passes through steering column or bulkhead
Connector corrosion or bent terminal at the ignition cylinder plug
Failed ignition cylinder sensor with internal short to sensor body/ground
Poor or missing insulation after previous repair or installation of an accessory
Less likely: ECU/input driver failure or transient damage from short

⚠️ Status

Ignition cylinder sensor circuit short to ground detected. Inspect sensor, connector and wiring for short to chassis ground.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 0.5-2.0 hours

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