Circuit Description
The powertrain control module (PCM) inhibits cruise control operation when certain conditions are not appropriate for cruise control operation. The PCM removes the ground from the cruise control inhibit signal circuit in order to disengage cruise control operation.
Conditions for Running the DTC
The PCM is commanding the SMCC module to inhibit cruise control operation (Cruise Inhibit circuit not grounded).
Conditions for Setting the DTC
| • | 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 conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.
Conditions for Clearing the MIL/DTC
| • | The DTC becomes history when the conditions for setting the DTC are no longer present. |
| • | The history DTC clears after 40 malfunction free warm-up cycles. |
| • | The PCM receives a clear code command from the scan tool. |
Diagnostic Aids
Check for the following conditions:
| • | Poor connection at the PCM. |
| Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection. |
| • | Damaged harness. |
| Inspect the wiring harness for damage. If the harness appears to be OK, observe the Cruise Status display on the scan tool while moving connectors and wiring harnesses related to the Stepper Motor Cruise Control module. A change in the display will indicate the location of the malfunction. |
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
The numbers below refer to the step numbers on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 | Is DTC P1662 also set? | -- | ||
3 |
Is the voltage near the specified value? | B+ | ||
4 |
Is the test lamp ON? | -- | ||
5 |
For Buick - Observe the instrument cluster "Cruise" indicator. Is the test lamp or the indicator ON? | -- | ||
6 | Replace the cruise control module. Refer to Cruise Control Module Replacement . Is action complete? | -- | -- | |
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .Replace the PCM. Is the action complete? | -- | -- | ||
8 | Locate and repair short to ground in the cruise engaged status circuit. Refer to Wiring Repairs . Is the action complete? | -- | -- | |
9 |
Did DTC P1554 set? | -- | System OK |
