GM Service Manual Online
For 1990-2009 cars only

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 the shift lever is place in neutral, or the transaxle range indicates a neutral position, the PCM will inhibit the cruise control system, and set DTC P1560.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P1560 Transaxle Not In Drive Cruise Control Disabled

Conditions for Running the DTC

    • The cruise control is enabled.
    • The cruise control is engaged.

Conditions for Setting the DTC

The shift lever is placed in neutral or the transaxle range indicates a neutral position.

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 without a malfunction.
    • The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

Shifting into neutral while cruise control is engaged will set this DTC.

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 the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Are any other DTCs also set?

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 3

3

This DTC will set when the vehicle is shifted into NEUTRAL or PARK while the cruise is engaged. Verify with the customer the conditions under which the DTC set.

Did the drivers actions 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

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