P15BC
DTC Troubleshooting: P15BC
DTC P15BC:
Electric Vacuum Pump Operating Time Exceeded
Special Tools Required
- Vacuum Pump/Gauge, 0-30 inHg Snap-on YA4000A or equivalent, commercially available
1. Turn the ignition switch to LOCK (0).
2. Do the battery terminal disconnection procedure Procedures, and wait several seconds.
3. Do the battery terminal reconnection procedure Procedures, then do this procedure after the troubleshooting.
4. Turn the ignition switch to ON (II). Do not start the engine.
Does the electric vacuum pump motor run?
YES -
Go to step 5.
NO -
Go to step 23.
5. Turn the ignition switch to LOCK (0).
6. Disconnect the brake booster pressure sensor hose (A) from the brake booster (B), and connect a vacuum pump/gauge, 0-30 inHg, to the brake booster pressure sensor hose.
7. Turn the ignition switch to ON (II).
8. Check the BRAKE BOOSTER PRESSURE SENSOR in the DATA LIST with the HDS before and after applying vacuum to the hose using the vacuum pump/gauge.
Does the indicated value change?
YES -
Go to step 9.
NO -
Replace the brake booster pressure sensor Service and Repair.�
9. Turn the ignition switch to LOCK (0).
10. Reconnect the brake booster pressure sensor hose to the brake booster.
11. Disconnect the brake booster vacuum hose from the intake manifold Service and Repair.
NOTE: Cap the brake booster vacuum hose connector on the intake manifold to prevent a vacuum leak, or dust entering the system.
12. Deplete the booster vacuum by pressing the brake pedal several times until the brake pedal becomes hard.
13. Turn the ignition switch to ON (II).
14. Check the ELECTRIC VACUUM PUMP RELAY in the DATA LIST with the HDS, and start the engine while pressing the brake pedal lightly.
NOTE: Do not press the brake pedal hard; press the pedal gently until the brake lights turn on.
Does the pump run and shut off within 8 seconds?
YES -
Intermittent failure, the system is OK at this time. Check for loose terminals between the brake booster pressure sensor 3P connector, the electric vacuum pump relay 2 connector (4P), the electric vacuum pump 2P connector, and PCM connector B (44P). Refer to intermittent failures troubleshooting Initial Inspection and Diagnostic Overview.�
NO -
Go to step 15.
15. Turn the ignition switch to LOCK (0).
16. Substitute the known-good or new vacuum hose between the electric vacuum pump and 3-way joint.
17. Deplete booster vacuum by pressing the brake pedal several times until the brake pedal becomes hard.
18. Turn the ignition switch to ON (II).
19. Check the ELECTRIC VACUUM PUMP RELAY in the DATA LIST with the HDS, and start the engine while pressing the brake pedal lightly.
NOTE: Do not press the brake pedal hard; press the pedal gently until the brake lights turn on.
Does the pump run and shut off within 8 seconds?
YES -
Replace the original vacuum hose between the electric vacuum pump and 3-way joint Locations.�
NO -
Go to step 20.
20. Check for vacuum leaks or clogging at these parts:
- Brake booster pressure sensor hose.
- Brake booster vacuum hoses and their joints.
- Check valve (intake manifold).
- Brake booster.
Are the parts OK?
YES -
Replace the electric vacuum pump Service and Repair.�
NO -
Repair or replace the leaking or clogged part (s).�
21. Turn the ignition switch to LOCK (0).
22. Check the connection and terminal fits of the electric vacuum pump 2P connector.
Is the connector properly connected?
YES -
Go to step 23.
NO -
Connect the electric vacuum pump 2P connector properly. If necessary, repair or replace the harness.�
23. Remove electric vacuum pump relay 2, and check it Testing and Inspection.
Is the relay OK?
YES -
Go to step 24.
NO -
Replace electric vacuum pump relay 2.�
24. Remove the No. 17 (15 A) fuse from the under-hood fuse/relay box.
25. Remove the No. 31 (7.5 A) fuse in the auxiliary under-hood fuse/relay box.
26. Check for continuity between electric vacuum pump relay 2 terminal No. 2 and No. 31 (7.5 A) fuse in auxiliary under-hood fuse/relay box terminal No. 1.
Is there continuity?
YES -
Go to step 27.
NO -
Repair an open in the wire between electric vacuum pump relay 2 and the No. 31 (7.5 A) fuse in the auxiliary under-hood fuse/relay box.�
27. Remove electric vacuum pump relay 1.
28. Install the No. 17 (15 A) fuse in the under-hood fuse/relay box.
29. Connect the electric vacuum pump relay 1 connector terminals No. 1 and No. 2, and electric vacuum pump relay 2 connector terminals No. 1 and No. 2 with jumper wires.
Does the electric vacuum pump motor run?
YES -
Check for loose terminals in the brake booster pressure sensor 3P connector, the electric vacuum pump relay 2 connector (4P), the electric vacuum pump 2P connector, and PCM connector B (44P), then update the PCM if it does not have the latest software PCM Update, or substitute a known-good PCM Initial Inspection and Diagnostic Overview, then go to step 1 and recheck. If no DTCs are indicated, and the PCM was substituted, replace the original PCM Service and Repair.�
NO -
Go to step 30.
30. Disconnect the electric vacuum pump 2P connector Service and Repair.
31. Measure the voltage between electric vacuum pump 2P connector terminal No. 1 and body ground.
Is there battery voltage?
YES -
Go to step 32.
NO -
Repair an open in the wire between electric vacuum pump relay 2 and the electric vacuum pump.�
32. Check for continuity between electric vacuum pump 2P connector terminal No. 2 and body ground.
Is there continuity?
YES -
Replace the electric vacuum pump Service and Repair.�
NO -
Repair an open in the wire between the electric vacuum pump and body ground (G401).�