Damaged or chafed wiring in the crank sensor signal circuit, shorting to a voltage source or to the sensor's power feed; Failed crankshaft position sensor internally shorted, producing an abnormally high output; Corroded, loose, or contaminated connector pins at the sensor or ECM; Metallic debris or a damaged reluctor wheel tooth causing an irregular signal that the ECM reads as high; Electrical interference from a failing ignition component or aftermarket accessory wired too close to the crank sensor harness; Faulty ECM driver circuit for the crank sensor input (rare but documented on older Jaguar models)

DTC codes / Jaguar codes / P1246

P1246 · JaguarCrank Signal High Input

Q: What does code P1246 mean?

Crank Signal High Input. P1246 on a Jaguar means the engine control module (ECM) has detected an abnormally high voltage on the crankshaft position sensor signal circuit, which it interprets as a crank signal that is too strong or out of range. The ECM expects the crank sensor to produce a clean, alternating low-voltage waveform as the reluctor wheel teeth pass the sensor, and a signal that stays high or spikes beyond the expected threshold triggers this code.

P1246 on a Jaguar means the engine control module (ECM) has detected an abnormally high voltage on the crankshaft position sensor signal circuit, which it interprets as a crank signal that is too strong or out of range. The ECM expects the crank sensor to produce a clean, alternating low-voltage waveform as the reluctor wheel teeth pass the sensor, and a signal that stays high or spikes beyond the expected threshold triggers this code.

SystemPowertrain

Code typeJaguar specific

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering (injector circuits)

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Intermittent or complete engine stall, especially when the engine is hot or at low RPM
Extended cranking before the engine starts, or a no-start condition
Rough running, misfiring, or loss of power under acceleration
Tachometer needle fluctuating or dropping to zero while driving
Poor fuel economy or increased emissions due to incorrect timing signals

Common causes, most likely first

Damaged or chafed wiring in the crank sensor signal circuit, shorting to a voltage source or to the sensor's power feed
Failed crankshaft position sensor internally shorted, producing an abnormally high output
Corroded, loose, or contaminated connector pins at the sensor or ECM
Metallic debris or a damaged reluctor wheel tooth causing an irregular signal that the ECM reads as high
Electrical interference from a failing ignition component or aftermarket accessory wired too close to the crank sensor harness
Faulty ECM driver circuit for the crank sensor input (rare but documented on older Jaguar models)

How to diagnose and fix it

Connect a scan tool and record live crank sensor signal voltage and RPM data during cranking and while the fault is active
Visually inspect the crank sensor, its reluctor wheel, and the full harness routing for chafing, debris, or heat damage
Disconnect the sensor and measure resistance and output voltage with a multimeter or oscilloscope, comparing to Jaguar specifications
Check the sensor connector and ECM connector pins for corrosion, tightness, and correct pin fit; clean or repair as needed
Back-probe the signal wire with a scope to confirm whether the high input originates at the sensor or from a wiring short
Repair or replace the faulty section of harness, the sensor, or the connector, then clear the code and verify with a road test
If the signal remains high with a known-good sensor and verified wiring, test the ECM input circuit and replace the ECM only as a last resort

Crank Signal High Input on Jaguar

A high input code is frequently caused by a short to voltage in the signal wire rather than a failed sensor, so replacing the crank sensor first often does not fix the fault.
Metallic debris clinging to the sensor tip or a chipped reluctor wheel tooth can produce a signal the ECM reads as high, and this is easily missed during a quick visual check.
On some Jaguar models, a failing ignition coil or aftermarket alarm wiring routed near the crank harness induces electrical noise that mimics a high crank signal.
The ECM may set P1246 intermittently and store no other codes, leading technicians to dismiss it as a ghost code when a pending fault is actually present.
Always check for a loose or corroded ground at the engine block, because a poor ground reference can shift the sensor signal voltage high and trigger this code.

Can I keep driving with P1246?

You can drive cautiously if the engine runs normally and the light is steady, but avoid hard acceleration and long trips until the fault is diagnosed. If the engine stalls, cranks without starting, or the tachometer drops out, stop driving and arrange a tow to prevent a breakdown in traffic.

Tools that help

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Guidance is general and written for Jaguar vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.