Circuit Description
The cruise control module uses the cruise engaged circuit to request cruise control. If improper conditions are present, the powertrain control module (PCM) will disable cruise control via the cruise inhibit control circuit. During cruise control, if a sudden rate of increase in vehicle speed occurs (i.e., vehicle speed sensing problem or traveling on icy roads), the PCM will inhibit the cruise control system, and set DTC P1564.
Conditions for Running the DTC
| • | The cruise control is enabled. |
| • | The cruise control is engaged. |
Conditions for Setting the DTC
The PCM detects an extremely rapid rate of vehicle acceleration.
Action Taken When the DTC Sets
| • | The PCM disables cruise control. |
| • | The PCM will not illuminate the malfunction indicator lamp (MIL). |
| • | The PCM will store conditions which were present when the DTC set as Fail Records data only. |
Conditions for Clearing the DTC
| • | The History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear DTC Information function. |
Diagnostic Aids
This diagnostic trouble code (DTC) is an information DTC only. The DTC indicates the reason that the PCM disabled the cruise control system. Be sure to check with the customer for the conditions that set the DTC.
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may assist in diagnosing the condition. The information may help determine how often the condition that set the DTC occurs.
Step | Action | Yes | No |
|---|---|---|---|
1 | Did you perform A Diagnostic System Check - Cruise Control? | Go to Step 2 | |
2 | Are any other DTCs also set? | Go to Step 3 | |
3 | Since this DTC will set when a sudden rate of increase in vehicle speed occurs (i.e., vehicle speed sensing problem or traveling on icy roads) while the cruise is engaged, check with the customer to verify the conditions under which the DTC set. Did the drivers actions or road conditions cause this DTC to set? | Go to Step 4 | Go to Diagnostic Aids |
4 | Explain system operation to the customer and clear this DTC. Is the action complete? | System OK | -- |
