STEP/SEQUENCE RESULT WHAT TO DO NEXT TM 9-2320-363-20-1 Section 4 TROUBLESHOOTING CHARTS E.  FLASH CODE: 36 J1587 CODE: P100  4 - OIL PRESSURE CIRCUIT FAILED LOW (LOW VOLTAGE) 36-4  Check for +5 Volts Turn ignition off. Between 4 to Go to 36-5. Remove jumper wire. 6 volts. Connect vehicle harness to ECM. Turn ignition on. Less than Go to 36-8. Read voltage on OPS harness 4 volts. connector, socket C (red lead) to socket A (black lead).   Greater than Go to 36-10. 6 volts. 36-5  Check for Signal Open Turn ignition off. Less than or Go to 36-11. Disconnect the engine harness equal to 5 ohms on either connector at the ECM. reading install a jumper wire between Greater than Signal line (ckt#530) is open. sockets A and B of the OPS 5 ohms or open. Repair open.  Then go to 36-30. harness connector. Read resistance between sockets P2 and Y2 on the engine harness connectors. 36-6  Check for Short Remove jumper wire. Less than or Signal line (ckt#530) is shorted Disconnect the engine harness equal to 10,000 ohms. to the return line (ckt#452) or connector at the ECM. battery ground.  Repair short. Read resistance between sockets Then go to 36-30. A and B on the OPS harness connector. Greater than Go to 36-12. Also read resistance between 10,000 ohms or open. socket B and a good ground. on both readings. 36-7  Check ECM Connectors Check terminals at the ECM Terminals and Reprogram ECM.  Then go to harness connector (both the ECM connectors are okay. 36-30. and harness side) for damage; bent, corroded and unseated pins Problem found. Repair terminals/connectors. or sockets.  Especially W1, P2 Then go to 36-30. and Y2 terminals and pins at ECM. Change 3  3-345.291