Circuit Description
The powertrain control module (PCM) has the ability to disable the cruise control if 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 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 more than 2 seconds. |
| • | The vehicle acceleration or deceleration rate is too high. |
If any of these conditions are present, the PCM interrupts the ground on the cruise inhibit circuit to request that the cruise control be disengaged. If the cruise status signal indicates that cruise control is still engaged while the PCM is inhibiting cruise control operation, DTC P1554 is 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 longer than 1 second. |
Action Taken When the DTC Sets
The PCM stores the conditions which were present when the DTC set as Fail Records data only.
Conditions for Clearing the MIL/DTC
| • | A history DTC clears after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | DTC may be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed. |
Diagnostic Aids
Inspect for the following conditions:
| • | A faulty connection at the PCM. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connections. |
| • | Inspect the wiring harness for damage. If the harness appears to be OK, observe the Cruise Status display on the scan tool while moving the connectors and wiring harnesses related to the SMCC module. A change in the display indicates the location of the malfunction. |
If DTC P1554 cannot be duplicated, the information included in the Failure records data may be useful in determining how many ignition cycles have passed since the DTC was last set.
Test Description
The number(s) below refer to the step number(s) 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 voltage greater than the specified value? | 7V | ||
4 |
Is the test lamp ON? | -- | ||
5 |
Is the test lamp on? | -- | ||
6 | Replace the cruise control module. Refer to On-Vehicle Service in Cruise Control. Is action complete? | -- | -- | |
Replace the PCM. Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming . Is action complete? | -- | -- | ||
8 | Locate and repair short to ground in the cruise inhibit circuit. Refer to Repair Procedures in Wiring Repairs . Is action complete? | -- | -- | |
9 |
Did DTC P1554 set? | -- | System OK |
