Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the ETCS control relay and the PCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
2.
Determine possible failure area (+B DBW or VBDBW/DBW RLY OUT line, others):
Determine possible failure area (+B DBW or VBDBW/DBW RLY OUT line, others)
?1.
Turn the vehicle to the OFF (LOCK) mode.
?2.
Check the following fuse.
Fuse
No. A22 (15 A)
Location
Under-hood fuse/relay box
Is the fuse OK?
YES
Go to step 3.
NO
Go to step 9.
3.
Relay check:
Relay check
?1.
Remove the ETCS control relay (A) from the under-dash fuse/relay box.
The DBW RLY CL- wire is OK. Update the PCM if it does not have the latest software, or substitute a known-good PCM, then recheck. If DTC P1659 goes away and the PCM was updated, troubleshooting is complete. If DTC P1659 goes away and the PCM was substituted, replace the original PCM.?
NO
Repair an open in the DBW RLY CL- wire between the PCM (A19) and the ETCS control relay.?
9.
Shorted wire check (VBDBW/DBW RLY OUT line):
Shorted wire check (VBDBW/DBW RLY OUT line)
?1.
Remove the ETCS control relay (A) from the under-dash fuse/relay box.
?2.
Jump the SCS line with the HDS, and wait more than 1 minute.
Repair a short in the VBDBW/DBW RLY OUT wire between the PCM (C2) and the ETCS control relay. Also replace the No. A22 (15 A) fuse in the under-hood fuse/relay box.?
NO
The VBDBW/DBW RLY OUT wires are OK. Go to step 10.
10.
Determine possible failure area (+B DBW line, PCM):
Determine possible failure area (+B DBW line, PCM)
Repair a short in the +B DBW wire between the No. A22 (15 A) fuse and the under-dash fuse/relay box. If needed, replace the under-hood fuse/relay box. Also replace the No. A22 (15 A) fuse in the under-hood fuse/relay box.?