Symptoms

- Engine Light ON (or Service Engine Soon Warning Light)

Possible Causes

- ECM Short circuit condition - Shorted sensor on 5 volt circuit - Failed ECM

When Detected

The ECM has detected the sensor 5 volt reference circuit voltage is higher or lower than expected

Description

The Service Manual says The Engine Control Module (ECM) detects a voltage out of tolerance condition on the 5V reference 1 or 2 bus for more than 0.5 seconds.