P16DD

DTC P16DD: Electric Vacuum Pump Relay 1 Stuck ON

1. Turn the ignition switch OFF.
2. Remove electric vacuum pump relay 1, and check it.

Is the relay OK?

YES - Go to step 3.

NO - Replace electric vacuum pump relay 1.

3. Remove the No. 17 (15 A) fuse from the under-hood fuse/relay box and the No. 31 (7.5 A) fuse from the auxiliary under-hood fuse/relay box.
4. Check for continuity between electric vacuum pump relay 1 terminals No. 1 and No. 2.





Is there continuity?

YES - Repair short in the wires between electric vacuum pump relay 1 terminals No. 1 and No. 2.

NO - Go to step 5.

5. Short the SCS line with the HDS.
6. Disconnect PCM connector A (44P).
7. Turn the ignition switch ON (II).
8. Measure voltage between body ground and PCM connector A (44P) terminal No. 13.





Is there 3.0 V or more?

YES - Repair short to power in the wire between the No. 31 (7.5 A) fuse in the auxiliary under-hood fuse/relay box and the PCM.

NO - Go to step 9.

9. Measure voltage between body ground and PCM connector A (44P) terminal No. 12.





Is there any voltage?

YES - Repair short to power in the wire between electric vacuum pump relays 1 and 2 and the PCM.

NO - Update the PCM if it does not have the latest software, or substitute a known-good PCM, then go to step 1 and recheck. If no DTCs are indicated, and the PCM was substituted, replace the original PCM.