P1742
Manufacturer-specific Basic entry
Lockup Solenoid System
Severity
Medium
Typical repair cost
60 – 500 EUR
System
Powertrain
This is a manufacturer-specific code. Its exact meaning can differ between makes; the definition below follows the most common usage.
What it means
P1742 is defined as "Lockup Solenoid System". the engine control module stores it when the monitored condition for this component or system is outside the limits programmed by the manufacturer.
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Symptoms
- Check engine light on
- Rough or unstable idle
- Hesitation or poor acceleration
- Increased fuel consumption
- Possible limp mode with reduced power
Common causes
- Lockup Solenoid System worn, contaminated or out of calibration
- Mechanical problem in the system the sensor measures
- Air, vacuum or exhaust leak influencing the reading
- Wrong or low-quality replacement part
- Wiring resistance causing a small voltage offset
How to diagnose
- Compare the live Lockup Solenoid System reading with a known-good value or a second sensor at idle and at 2500 rpm
- Check for air, vacuum or exhaust leaks that could skew the reading
- Inspect the component for contamination and clean it if the design allows
- Verify the part number is correct for the engine
- Replace the Lockup Solenoid System if the reading remains out of specification
Frequently asked questions
Can I keep driving with P1742?
Usually yes for a short time, but expect reduced performance or higher fuel use. Have it diagnosed within a few days.
Will clearing P1742 fix it?
No. Clearing only erases the stored code; it returns as soon as the monitor runs again unless the cause is repaired.