DTC Two-Trip Detection Override

DTC TWO-TRIP DETECTION OVERRIDE

To re-create some DTCs during diagnosis, you need to reproduce, in back-to-back driving cycles, the conditions that caused the MIL to come on. This requirement is called two-trip detection. For example, to cause the MIL to come ON for DTC P1456 or P1457, you need a cold engine start, followed by a driving cycle (to reproduce the condition), and then a cool-down, followed by another cold start and another driving cycle.

The two-trip detection flinction can be bypassed and the DTC captured in only one driving cycle by jumping the service check connector with the SCS service connector (most models) or by jumping the SCS circuit ('98-99 Accords and '99 Odysseys).

To jump the SCS circuit on a '98-99 Accord or '99 Odyssey, use the PGM Tester (if you don't need it for other flinctions) or a jumper wire (if you need the Tester while the SCS is jumped). Here are the two methods:

With the PGM Tester:
Connect the Tester to the vehicle's DLC, and turn the ignition switch ON (II). Then, on the Tester menu, select 1. Honda Systems, and 2. SCS. The SCS is now jumped, and you can capture the DTC in one driving cycle.


With a jumper wire:




Backprobe the DLC between terminal 1 (BRN) and terminal 12 (BLK). Doing this allows you to connect the POM Tester to the DLC, and use the Tester during the test drive.

To re-create DTCs during your diagnosis, use each DTC's troubleshooting chart, and follow all conditions exactly (coolant temperature, rpm, throttle position, vehicle speed, etc.). You can't re-create some DTCs without using the correct conditions.