P1554

Diagnostic Chart:

Engine Controls Schematics: Cruise Control Module, EBCM and VSS:

CIRCUIT DESCRIPTION
The PCM has the ability to disable the cruise control if any conditions are detected which would make cruise control operation undesirable. The following conditions may cause the cruise control to be inhibited by the PCM:
^ The engine is not running long enough for cruise control operation.
^ The transaxle range switch indicates Park, Neutral, Low, or Reverse gear is selected.
^ The engine speed is too high or too low.
^ The vehicle speed is too high or too low.
^ The ABS system is active for longer than 2 seconds.
^ The vehicle acceleration or deceleration rate is too high.

If any of these conditions are present, the PCM opens the ground on the cruise inhibit circuit to request that cruise control be disengaged. The cruise control module detects the high signal voltage and disables the system. If the cruise engaged signal indicates that cruise control is still engaged while the PCM is inhibiting cruise control operation, DTC P1554 will be set.

CONDITIONS FOR SETTING THE DTC
^ The PCM is commanding the Stepper Motor Cruise Control (SMCC) module to inhibit cruise control operation.
^ The Cruise Status circuit signal indicates that the cruise control is engaged.
^ The above conditions are present for more than 1 second.

ACTION TAKEN WHEN THE DTC SETS
^ The PCM stores the DTC information into memory when the diagnostic runs and fails.
^ The Malfunction Indicator Lamp (MIL) will not illuminate.
^ The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A History DTC will clear after forty consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
^ The current DTC will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the MIL diagnostic trouble code.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Powertrain Control Module (PCM) Description, Clearing Diagnostic Trouble Codes.

DIAGNOSTIC AIDS

NOTE: Refer to Connector Test Adapter Kit J 35616-A Notice in Service Precautions.

If DTC P1554 cannot be duplicated, the information included in the Failure Records data can be useful in determining how many ignition cycles have passed since the DTC was last set.

If the problem is intermittent, refer to Intermittent Conditions. Intermittent Conditions

TEST DESCRIPTION
The number below refers to the step number on the diagnostic table.
7. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read-only Memory (EEPROM). If the PCM is replaced, the new PCM must be programmed.