P1554

Circuit Description
The PCM has the ability to disable cruise control if conditions are detected which would make cruise control operation undesirable. The following conditions may cause cruise control to be inhibited by the PCM:
^ Engine not running long enough for cruise control operation.
^ Transaxle range switch indicates park, neutral, low, or reverse gear selected.
^ Engine speed is too high or too low.
^ Vehicle speed is too high or too low.
^ ABS system is active for longer than 2 seconds.
^ 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 SMCC module to inhibit cruise control operation (Cruise Inhibit circuit not grounded).
^ The Cruise Status circuit signal indicates that cruise control is engaged.
^ The above conditions are present for longer 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.
^ A last test failed (Current DTC) will clear when the diagnostic runs and does not fail.
^ Use a scan tool in order to clear the MIL/DTC.
^ Interrupting the PCM battery voltage may or may not clear DTCs. This practice is not recommended.

Diagnostic Aids

Notice: Use the Connector Test Adapter kit J 35616-A for any test that requires probing the following items:
^ The PCM harness connectors
^ The electrical center fuse/relay cavities
^ The component terminals
^ The component harness connector
Using this kit will prevent damage caused by the improper probing of connector terminals.
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.


Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
7. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.