Cruise Control Move Output Circuit High Voltage
Circuit Description
The cruise control move circuit is used to indicate to the cruise control module the amount of accelerator pedal movement needed to maintain cruise set speed. The powertrain control module (PCM) pulse width modulates (PWM) ignition voltage on the cruise control move circuit at a 100 ms PWM rate. When the cruise control clutch is commanded On, the PCM will begin to PWM the cruise control move circuit as needed. Very short On-time pulses indicate to the cruise control module to keep the accelerator pedal at the same position. The PCM monitors the cruise control move circuit for low and high voltage faults. DTC P1581 sets when the cruise control move circuit is commanded Off or PWM Off-time, and the feedback voltage at the PCM is high.
Conditions for Setting the DTC
DTC P1581 will set if the cruise control move feedback voltage is greater than 2.5 volts with the cruise control move commanded Off or PWM Off-time when:
| • | The condition exists for longer than 500 milliseconds. |
| • | The ignition is On. |
DTC P1581 diagnostic runs continuously with the ignition On and the cruise control move commanded Off.
DTC P1581 is a type D DTC.
Diagnostic Aids
To locate an intermittent problem, use scan tool to monitor the C/C MOVE CKT. - OPEN or C/C MOVE CKT. - HIGH VOLT test with the ignition On, the engine Off. When a fault (open or a short to voltage) exists, the scan tool will display TEST FAIL for both tests.
The tests will fail only when the device is being commanded Off and the voltage at the PCM is high. The tests update every 100 ms whenever the ignition is turned On and the device is being commanded Off via the scan tool or the PCM.
Loss of cruise control module ground can also set this DTC. If this condition exists, DTC P1583 and P1587 will also set.
