Scan data and fault pattern
Engine-speed data while cranking, related camshaft faults and freeze-frame information help separate a signal problem from other non-start causes.
Non-start & cut-out diagnosis
Crankshaft Position Sensor Diagnosis & Replacement in South London
A non-start, sudden cut-out or engine-speed signal fault can involve the crankshaft sensor, wiring, connector, target wheel, timing or another control issue. SP88 tests the evidence before fitting a sensor.
South London & nearby SurreyWeekdays: 10:00, 12:00 or 14:00Weekends closed
A fault code is evidence, not automatic proof
The engine ECU relies on crankshaft position and speed information for ignition and injection timing. A stored code can describe a missing or implausible signal without identifying why it is wrong.
Power, ground and wiring
Supply, ground, connector condition and accessible wiring are checked where the sensor design allows it.
Sensor and target wheel
Heat-related failure, contamination, incorrect air gap or target-wheel damage can create intermittent or permanent signal loss.
Timing and control context
Mechanical timing, ECU supply, immobiliser and starter-speed problems can mimic or contribute to crank-signal faults.
How the visit works
Describe when it fails
Say whether the engine cuts out hot, restarts cold, cranks without starting or shows an engine-speed reading.
Test the signal path
SP88 checks scan and accessible circuit evidence before deciding that sensor replacement is justified.
Fit and verify
Where suitable, the correct sensor is fitted and starting, signal and stored faults are rechecked.
Intermittent cut-out can become a breakdown
If the engine cuts out in traffic or will not restart reliably, avoid continued driving. A sensor may be accessible, but the fault still needs confirmation before parts are ordered.
Mobile where suitable, workshop when necessary
Many crank-sensor diagnoses are suitable for mobile work. Replacement access ranges from straightforward to gearbox-side or under-vehicle locations; seized fixings, damaged targets or timing concerns may require workshop work.
Questions customers ask
Does a crankshaft-sensor code prove the sensor is faulty?
No. Wiring, connectors, target wheels, mechanical timing and low cranking speed can all affect the recorded signal.
Can the sensor fail only when hot?
Yes. Some sensors or connections become intermittent with heat, but the symptom should be supported by live data or circuit evidence where possible.
Can a car start with a bad crank sensor?
Some faults are intermittent, but a missing crank signal commonly causes a crank-no-start or sudden stall.
Does a new sensor need programming?
Many do not, but relearn or adaptation requirements vary by vehicle. Compatibility and procedure are checked first.
Send the vehicle details before booking
Include the registration, make and model, postcode and symptoms. That helps SP88 check likely access, parts and whether the first visit should be mobile diagnosis or workshop work.