Oil Pressure - Incorrect Low Warning

33-20

Engine Oil Pressure - Incorrect Low Oil Pressure Warning - Repair Procedure

MODEL: XJ12 Sedan 1994 MY ON

DATE: 1/95

ISSUE:

The low oil pressure warning light on XJ12 Sedan vehicles may illuminate at idle with the engine at normal operating temperature and idle oil Pressure within specification (minimum idle oil pressure - 7 psi [0.5 bar]).

Energy efficient engine oils are thinner and may cause the low oil pressure warning system to illuminate at idle when the oil pressure is within specification.

ACTION:

If a customer complains of a low oil pressure warning at idle and the oil pressure is within specification, replace the existing oil pressure transducer with an oil pressure sensor switch.

NOTE
The oil pressure switch will affect the operation of the oil pressure gauge. The oil pressure gauge will read at mid-scale under all normal driving conditions. It will only move (to zero) if a low oil pressure warning occurs.

Follow the procedure below to replace the oil pressure transducer with an oil pressure sensor switch.

ENGINE OIL PRESSURE TRANSDUCER REPLACEMENT PROCEDURE

1. Check engine oil level.

2. At normal operating temperature, check that engine idle speed and oil pressure are within specification.

Engine idle speed: 700 +/- 25 rpm
Engine oil pressure at idle: 7 psi (0.5 bar) minimum.

3. If the idle speed and oil pressure are within specification, replace the engine oil pressure transducer with an engine oil pressure sensor switch (part number LMC 5642AA).

4. Connect an engine harness link lead (part number LMD 3325AA) between the oil pressure sensor switch and the engine harness transducer connector. Tape the link lead to the harness.

5. Run the engine at idle (normal operating temperature). The pressure gauge should be at mid-scale and there should be no low oil pressure warning.




Parts/Warranty Information