Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's security system, which prevents the engine from starting without the correct key, is having trouble communicating correctly.
The EWS system is responsible for ensuring that the correct key is used to start the vehicle. A parity error indicates a problem in the communication between the EWS and the engine control unit (ECU).
The P1662 code is triggered when the Electronic Immobilizer System (EWS) detects a parity error in the telegram or data packet sent to the Engine Control Unit (ECU). This error indicates a communication issue, which could be due to electrical interference, wiring problems, or a fault in one of the components.
• Engine does not start
• Security light on the dashboard
• Intermittent starting issues
• Faulty EWS module
• Wiring issues between EWS and ECU
• Defective key or key transponder
EWS: Electronic Immobilizer System
ECU: Engine Control Unit
• Check for any additional error codes.
• Inspect the wiring and connections between the EWS and ECU.
• Test the key and transponder for proper operation.
• Repair or replace faulty wiring or connectors.
• Replace the EWS module if necessary.
• Reprogram or replace the key transponder.
• OBD-II scanner
• Multimeter
• Key programming tool
$150 - $500
Moderate
• BMW 3 Series
• BMW 5 Series
• Mini Cooper
• Ensure keys are not damaged or exposed to strong magnetic fields.
• Regularly inspect wiring for wear and tear.
• Avoid aftermarket modifications to the ignition system.
Communication Error
• Avoid using non-genuine keys.
• Have a spare key available in case of failure.
• Consult a professional if the issue persists.
Check vehicle warranty for coverage on electronic components.
This code is commonly associated with BMW and Mini vehicles due to their complex security systems.
High – This issue can prevent the vehicle from starting.
Always ensure your vehicle's security system is functioning properly to prevent theft.
• Vehicle in 'On' position without starting.
• Use of diagnostic tools to read error codes.
The EWS module is typically located near the steering column or under the dashboard.
Q: Can I drive with a P1662 code?
A: No, if this code is active, the vehicle may not start.
Q: How do I clear a P1662 code?
A: Fix the underlying issue, then use an OBD-II scanner to clear the code.
Pro · Four-system diagnostics
A handheld scanner aimed at engine, transmission, ABS, and airbag diagnostic work.
Chassis and ABS faults usually need a scanner that can read brake-system data directly.
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Universal · Torque wrench
Useful when reassembly torque matters for wheel, suspension, and under-hood fasteners.
Useful when wheel, hub, or suspension hardware needs correct reassembly torque.
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Universal · Drive-on ramps
Helpful for safer access underneath the vehicle during exhaust, EVAP, and underbody inspection work.
Helpful for safer access during underbody inspection work.
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