GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The powertrain control module (PCM) inhibits cruise control operation when certain conditions are not appropriate for cruise control operation. The PCM removes the ground from the cruise control inhibit signal circuit in order to disengage cruise control operation.

Conditions for Running the DTC

The PCM is commanding the cruise control module to inhibit cruise control operation.

Conditions for Setting the DTC

    • The PCM detects a cruise control engaged signal from the cruise control module, while inhibiting cruise control operation.
    • The above conditions are present for more than 1 second.

Action Taken When the DTC Sets

The PCM stores conditions which were present when the DTC set as Failure Records only. This information will not be stored as Freeze Frame Records.

Conditions for Clearing the MIL/DTC

    • The DTC becomes history when the conditions for setting the DTC are no longer present.
    • The history DTC clears after 40 malfunction free warm-up cycles.
    • The PCM receives a clear code command from the scan tool.

Diagnostic Aids

Check for the following conditions:

    • A faulty connection at the PCM. Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connections. Use a corresponding mating terminal to test for proper terminal tension.
    • Inspect the wiring harness for damage. If the harness appears to be OK, observe the Cruise Status display on the scan tool while moving the connectors and wiring harnesses related to the cruise control module. A change in the display will indicate the location of the malfunction.

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.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read-only memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

DTC P1554 - Cruise Control Status Circuit

Step

Action

Yes

No

Schematic Reference: Cruise Control Schematics

1

Did you perform A Diagnostic System Check - Cruise Control?

Go to Step  2

Go to Diagnostic System Check - Cruise Control

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, monitor the DTC information for DTC P1585 in the powertrain control module (PCM).

Is DTC P1585 also set?

Go to DTC P1585

Go to Step  3

3

With a scan tool, observe the Cruise Requested display.

Does the Cruise Requested display indicate YES?

Go to Step  5

Go to Step  4

4

  1. Review and record the Failure Records Information.
  2. Operate the vehicle within the Failure Records condition.
  3. Using a scan tool, monitor the Specific DTC Information for DTC P1554 until the test runs.

Does the scan tool indicate that DTC P1554 failed this ignition?

Go to Step  5

Go to Diagnostic Aids

5

  1. Turn OFF the ignition.
  2. Disconnect the cruise control module harness connector.
  3. Turn ON the ignition, with the engine OFF.
  4. Using the scan tool, observe the Cruise Requested display.

Does the Cruise Requested display indicate YES?

Go to Step  6

Go to Step  7

6

  1. Turn OFF the ignition.
  2. Disconnect the appropriate PCM connector.
  3. Test the Cruise Engaged signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step  9

Go to Step  8

7

Replace the cruise control module. Refer to Cruise Control Module Replacement .

Did you complete the replacement?

Go to Step  9

--

8

Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Programming in Engine Controls

Replace the PCM. Refer to Powertrain Control Module Replacement in Engine Controls.

Did you complete the repair?

Go to Step  9

--

9

  1. Use a scan tool in order to clear the DTC.
  2. Operate the vehicle within the conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step  2

System OK