Circuit Description
This diagnostic test is designed to set when the vehicle speed is increasing at an extremely rapid rate (wheelspin). It is a protective measure to disable the cruise control when the vehicle suddenly accelerates for example, when traveling on icy roads. Under these conditions, DTC P1564 will set and should be considered normal. The driver should be advised why the cruise disengaged. Clear the DTC and road test vehicle to verify normal operation.
Conditions for Setting the DTC
Test Condition
Cruise control engaged.
Failure Condition
Vehicle speed increases more than 16 MPH in 1 second.
Action Taken When the DTC Sets
| • | PCM disables cruise control. |
| • | The Malfunction Indicator Lamp (MIL) will not illuminate. |
| • | No message will be displayed. |
Conditions for Clearing the DTC
| • | A History DTC will clear after forty consecutive warm-up cycles with no failures of any non-emission related diagnostic test. |
| • | A Last Test Failed (current) DTC will clear when the diagnostic runs and does not fail. |
| • | Use a scan tool to clear DTCs. |
| • | Interrupting PCM battery voltage may or may not clear DTCs. This practice is not recommended. Refer to Clearing Diagnostic Trouble Codes in PCM Description and Operation. |
Diagnostic Aids
Reviewing the Failure Rec. may help diagnose an intermittent failure by showing how long ago and under what conditions the DTC set.
Clear the DTC and operate the vehicle under the conditions in which the DTC set if a fault condition is suspected.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to A Powertrain On Board Diagnostic (OBD) System Check | |
2 | Is DTC P0503 also set? | -- | Go to Section 7 diagnosis | |
3 | Since most occurrences of DTC P1564 are caused by wheelspin due to icy, wet or slippery conditions, check with the customer to verify the conditions under which the DTC set. Did the road conditions cause this DTC to set? | -- | Fault not present. Refer to Diagnostic Aids | |
4 | Explain system operation to the customer and clear this DTC. Is the repair complete? | -- | System OK | -- |
