Circuit Description
The PCM has the ability to disable cruise control if conditions are detected that would make cruise control operation undesirable. The following conditions may cause the cruise control to be inhibited by the PCM:
| • | The engine has not been running long enough for cruise control operation. |
| • | The transaxle range switch indicates park, neutral, low, or reverse gear 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 will interrupt the ground on the cruise inhibit circuit to request that 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 will set.
Conditions for Running the DTC
The PCM is commanding the stepper motor cruise control (SMCC) module to inhibit cruise control operation. This means the cruise inhibit circuit is 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 doesl not illuminate the malfunction indicator lamp (MIL). |
| • | The PCM stores the conditions that were present when the DTC set as Fail Records data only. This information is not stored as Freeze Frame data. |
Conditions for Clearing the MIL/DTC
| • | A history DTC clears after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | A DTC can be cleared by using the scan tool Clear Information function or by disconnecting the PCM battery feed. |
Diagnostic Aids
Check for the following conditions:
| • | Faulty connections 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. Use a corresponding mating terminal to test for proper terminal tension. |
| • | A 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 | Values | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||
2 | Is DTC P1585 also set? | -- | ||
3 |
Is the voltage more than the specified value? | 7 V | ||
4 |
Is the test lamp ON? | -- | ||
5 |
Was a problem found? | -- | ||
6 | Replace the cruise control module. Refer to Cruise Control Module Replacement in Cruise Control. Is the action complete? | -- | -- | |
|
Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming Is the action complete? | -- | -- | ||
8 | Locate and repair the short to ground in the cruise engaged status circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | -- | |
9 |
Did DTC P1554 set? | -- | System OK |
