Reatta V6-231 3.8L VIN C SFI (1990)
Oil Level Sensor: Customer Interest
Low Oil Level Warning Indicator - False Message
Bulletin 90-8-13
Date Nov. '90
Ref. No. 90-191-8
Corp. Ref. No. 918108R
SUBJECT:
LOW OIL LEVEL MESSAGE OPERATION (DIAGNOSIS AND NEW OIL LEVEL SENSOR AND OIL PAN RELEASED)
MODELS AFFECTED: 1988-90 RIVIERA/REATTA
THIS BULLETIN IS BEING REVISED TO INCLUDE OIL PAN KIT AND SERVICE INFORMATION. PLEASE DISCARD 90-6-3
(CORPORATION NO. 918108R).
Some 1989-1990 Buick Rivieras/Reattas may exhibit an intermittent false low oil level warning message due to either an inoperative oil level sensor or a
misformed oil pan.
IMPORTANT:
1.
Some customers may confuse oil pressure warnings with low oil level messages. It is critical to identify which oil warning message (pressure or
level) was displayed before attempting to repair an oil warning condition.
With either an oil level sensov, inoperative all the time or a misformed oil pan, the message will appear to be intermittent because of the way that
the oil level is tested by the body computer. See "Oil Level Sensor System Operation", in this bulletin.
A new sensor, P/N 1649745, has been released. The new sensor requires a gasket or seal which must be ordered separately as P/N 25531045. The seal
must be replaced whenever a sensor is replaced.
A new oil pan has been released for service and 1990 production on cars with 3800 engines built on or after July 2, 1990. The engine build date can be
found on a sticker on the rear valve cover and can be viewed by looking past the brake master cylinder from the driver's side of the car. The new pan
requires a new gasket, oil pump screen, oil pump screen gasket, and dipstick. These parts can be ordered through GMSPO as a kit using P/N 12350269.
NOTE:
Oil Pan Kit, Part No. 12350269, may also be used to correct an oil pan leak on 1989-90 Rivieras/Reattas. Please reference Bulletin 90-6-12 for details.
Parts are currently available from GMSPO.
TO DIAGNOSE LOW OIL LEVEL MESSAGES:
1.
Check the oil level using the dipstick.
2.
Turn the key to on with the engine off. If the engine has been running, allow time for the oil to drain back into the oil pan.
3.
Enter service diagnostics and monitor BCM Input BI88. If the input is "HI", go to 4A. If the input is "LO", go to 4B.
4A.
If the input reads "HI" with the oil level OK, disconnect the oil level
sensor connector and jumper the harness terminals together.
^
If input BI88 changes to "LO":
-
Replace the oil pan, oil pump screen, dipstick, and sensor.
^
If input BI88 remains "HI" with the terminals jumpered, check for an open in circuit 114 from the BCM to the sensor; and check the sensor
ground circuit for continuity to ground. Repair any wiring faults found and reconnect the sensor. (Go back to step 3.)
4B. If value reads "LO" with oil level OK (possible intermittent sensor or wiring).
^
In Diagnostics, monitor input BI88 while cycling wiring and connectors between the oil level sensor and the BCM. Any open circuit between
the sensor and BCM or between the sensor and ground will cause the oil level input to be "HI" and could cause a false low oil level message.
The X/O status indicator will change from 0 to X if an open occurs.
IMPORTANT:
