Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Oil Light Flashes For No Reason-Faulty Circuit Board (90-013)
Reference number: 90-013
OIL LIGHT FLASHES FOR NO REASON-FAULTY CIRCUIT BOARD
TECHNICAL SERVICE BULLETIN
LOW-OIL PRESSURE LIGHT FLASHES
Model(s): 1986-90 Acura Legend
Group: Electrical
Bulletin No.: 90-013
Date: April 29, 1991
VIN Application: ALL
Symptom: Oil Pressure Light Flashes
SYMPTOM
The low-oil pressure light "blinks" at random for no apparent reason: Oil pressure at idle measures more than 10 psi, and oil level is at "full" on the dipstick.
PROBABLE CAUSE
A faulty solder joint on the printed circuit board.
CORRECTIVE ACTION
Check and replace the printed circuit board. If the board is OK, check for an open circuit in the YEL/RED wire.
- Partially remove the gauges from the dashboard. See Fig 1 .
- Turn the ignition switch to "ON" and wiggle the ribbon cable (at the left side) between the two panels.
- If the oil pressure light flashes when the cable moves, the cable's solder joint may be faulty. Replace the light panel. If the light doesn't flash, go on to step 4. See Fig 2 .
- Disconnect the oil pressure switch, then check for an open circuit. Turn the ignition to "ON," and connect the YEL/RED wire to ground in three places in the sequence shown in Fig 3 . The oil light should go on each time; if it doesn't, find and repair the open. (If it flashes, turn the key off-and-on to reset the flasher, and try again.)
| Model | Part Number |
|---|---|
| 1986-87 4-door | 78145-SD4-A01 |
| 1988 4-door | 78145-SG0-A02 |
| 1989-90 4-door | 78145-SD4-A11 |
| 1987-90 Coupe | 78145-SG0-A02 |
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.