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P1237

VSV 2 Circuit.

  • Jaguar
  • Powertrain
  • Manufacturer code
  • Low severity

How this code is built

P
SystemPowertrain
1
Defined byThe manufacturer
2
AreaFuel and air metering (injector circuit)
37
FaultThe specific fault in that area

What it means

On Jaguar, P1237 means the engine control module has detected a fault in the electrical circuit for vacuum switching valve 2 (VSV 2), a solenoid-operated valve that controls a vacuum line. The module saw a voltage or current at the valve's driver circuit that did not match what it commanded, such as an open circuit, a short to earth or a short to voltage. Which system VSV 2 controls depends on the model, engine and year, so confirm this for the specific vehicle.

Symptoms

  • Malfunction indicator lamp on
  • Rough or unstable idle in some conditions
  • Reduced performance or hesitation, if the valve controls an engine-related vacuum function
  • Fuel smell or evaporative-related faults logged alongside, if the valve is part of that system
  • Failed emissions test
  • No noticeable change in driving at all

Possible causes

  • Faulty VSV 2 solenoid with an open or shorted internal coillikely
  • Damaged, chafed or corroded wiring between the valve and the control modulelikely
  • Loose, corroded or water-damaged connector at the valve or control modulelikely
  • Blown fuse or a fault in the power supply to the valvepossible
  • Valve physically stuck or its vacuum hoses cracked, blocked or disconnected, leading to a related faultpossible
  • Fault in the control module output driverrare

How to diagnose

  1. Read all stored and pending codes and the freeze frame data, noting any other codes that point to the same system.
  2. Check the workshop information for this model and engine to identify what VSV 2 controls and where it is fitted.
  3. Visually inspect the valve, its connector, the wiring harness and the vacuum hoses for damage, heat, chafing, corrosion or loose fittings.
  4. Check the relevant fuse and confirm the supply voltage at the valve connector with the ignition on.
  5. Measure the solenoid coil resistance and compare it with the specification for the model.
  6. Use a scan tool to activate the valve and listen or feel for it clicking, and check that the control module output changes.
  7. Test the wiring for continuity, short to earth and short to voltage between the valve and the control module, with the connectors disconnected.
  8. Clear the code and road test, then recheck to see whether it returns.

How to fix

  • Replace the VSV 2 solenoid if its resistance is out of specification or it fails the activation test.
  • Repair or replace any damaged wiring, and refit any connectors that are loose or corroded.
  • Replace any blown fuse once the cause of the overload has been found and fixed.
  • Replace any cracked, blocked or disconnected vacuum hoses on the valve circuit.
  • Have the control module output checked, and replace or repair the module only after the wiring and valve have been proven good.

Can I keep driving?

Low severity

The car can normally be driven while you arrange a repair, as this is an electrical circuit fault on a small valve. If the engine runs poorly or other related codes appear, have it checked sooner.

Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.

This code for other makes

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