Oil Pressure - Low Indicator Blinks On Start-up

SOURCE:
Honda Service News June 2004

TITLE:
Low Oil Pressure Indicator Blinks at Start-up

APPLIES TO:
2003-04 Pilot

SERVICE TIP:
If a owner complains that the low oil pressure indicator starts to blink after the engine starts, but there's plenty of oil in the engine, the problem could be a bad battery. If the battery is bad, the starter motor load will drop the battery voltage more than 2.5 volts for more than 1 second. This voltage drop also happens to trigger the low oil pressure warning alarm, causing the low oil pressure indicator to blink.

To fix this problem, swap the battery with a known-good one, and start the engine about 10 times. If the low oil pressure indicator stays off after each engine start, then the original battery is probably bad.

To confirm your suspicions, use a battery tester. Keep in mind, though, if you're using the ED-18, a bad battery could still test OK; if you're using the VAT-40 and a voltmeter, a bad battery will fail the test.