P1554

Circuit Description

The PCM will not allow cruise control operation under certain conditions, for example, vehicle speed is too low. This is done by the PCM grounding the 12 volt cruise inhibit signal (CKT 83) sent by the cruise control module. If the PCM is allowing cruise operation and the customer requests cruise, the cruise control module will ground the cruise engaged signal (CKT 396) to the PCM. This diagnostic is used to compare the cruise inhibit output versus the cruise engaged input. If the PCM detects that the cruise control module is signaling that it is engaged by grounding CKT 396 while the PCM is inhibiting cruise operation on CKT 83, DTC P1554 will set.

Conditions for Running the DTC

The PCM is sending out a cruise inhibit signal.

Conditions for Setting the DTC

The PCM monitors a signal that cruise is engaged.

Action Taken When the DTC Sets

^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ No message will be displayed.

Conditions for Clearing the DTC

^ A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test.
^ A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail.
^ Use a scan tool to clear DTCs.
^ Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Diagnostic Aids

Both the Cruise Engaged and the Cruise displays can be monitored at the same time to aid in diagnosing an intermittent fault.

Clear the DTC and operate the vehicle under the conditions in which the DTC set if a fault condition is suspected.