- Check the RP sensor signal circuit, +5V circuit for open.
Is a problem found?
YES – Repair the RP sensor signal or +5V circuit. 
NO – Go to step 11.
- Check the RP sensor signal voltage.
Is about 5V indicated?
YES – Substitute a known-good ECM and recheck. If symptom/indication goes away, replace the original ECM.
NO – Go to step 12.
- Turn the ignition switch OFF.
- Measure the resistance of RP sensor.
Is there 0.9 – 1.3 ohms (At room temperature; about 20°C (68°F))?
YES – Go to step 14.
NO – Replace the RP sensor.
- Recheck the DTC P1087 troubleshooting.
Was a problem completed?
YES – System is OK.
NO – Replace the supply pump.
| NOTICE |
The battery power supply short circuit to 5 V power supply damages the ECM.