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 powertrain control module (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. Refer to Powertrain Control Module Description , Clearing Diagnostic Trouble Codes. |
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
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 .
Test Description
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 P1585 also set? | -- | ||
3 |
Is voltage near the specified value? | 12V | ||
4 |
Is the test light 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? | -- | -- | |
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 Engaged circuit. Is action complete? | -- | -- | |
9 |
Did DTC P1554 set? | -- | System OK |
