Circuit Description
Caution: Refer to SIR Caution in the Preface section.
Disable the inflatable restraint steering wheel module when performing this diagnostic table. Refer to SIR Disabling and Enabling.
The cruise control switch is an input to the powertrain control module (PCM)/engine control module (ECM). The PCM/ECM monitors the cruise control set/coast and resume/accelerate switch signal circuit in order to detect when a cruise control function has been requested. The PCM/ECM detects a specific voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit when a cruise control function switch is activated, with each switch having a different predetermined voltage value.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0564 Cruise Control MultiFunction Switch Circuit
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The cruise control On/Off switch is ON. |
Conditions for Setting the DTC
This DTC sets when the PCM/ECM detects an invalid voltage signal on the cruise control set/coast and resume/accelerate switch signal circuit for greater than 1.5 seconds.
The PCM/ECM runs this diagnostic every 0.05 seconds.
Action Taken When the DTC Sets
| • | The PCM/ECM stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The PCM/ECM records the operating conditions at the time the diagnostic fails. The PCM/ECM stores this information in the Failure Records. |
| • | The Cruise Control System is disabled. |
Conditions for Clearing the DTC
| • | A last test failed, or the current DTC, clears when the diagnostic runs and does not fail. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if failures are not reported by this or any other emission related diagnostic. |
| • | Use a scan tool in order to clear the DTC. |
Diagnostic Aids
| • | With a scan tool, observe the cruise control function switch parameters, in the Body and Accessories Cruise Control data list, while rotating the steering wheel to both steering stops and individually activating each cruise control function switch separately. This will help eliminate the possibility of an internally shorted inflatable restraint steering wheel module coil. |
| • | For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections. |
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics Connector End View Reference: Master Electrical Component Listin Wiring Systems | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the voltage measure at the specified value? | B+ | Go to Step 3 | Go to Step 8 |
3 |
Important: The cruise control on/off switch must be turned ON in order to correctly view the set/coast switch and the resume/accel switch resistance values with the DMM.
Do the cruise control function switch resistance values measure between the specified values? | Off = O.L. On = 7.8 K-8.6 K ohms Resume = 2.7 K-3.0 K ohms Set = 1.2 K-1.3 K ohms | Go to Step 4 | Go to Step 5 |
4 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a high resistance, for a short to voltage, or for a short to ground between the cruise control switch and the powertrain control module (PCM)/engine control module (ECM). Refer to Circuit Testing and to Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 7 |
5 | Test the cruise control set/coast and resume/accelerate switch signal circuit for a high resistance, for a short to voltage, or for a short to ground between the cruise control switch and the cruise control switch connector. Refer to Circuit Testing and to Wiring Repairs. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 6 |
6 | Inspect for poor connections at the harness connector of the cruise control switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9 |
7 | Inspect for poor connections at the harness connector of the PCM/ECM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs. Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10 |
8 | Repair the high resistance in the ignition 1 voltage circuit. Refer to Circuit Testing and to Wiring Repairs. Did you complete the repair? | -- | Go to Step 11 | -- |
9 | Replace the cruise control switch. Refer to Cruise Control Switch Replacement . Did you complete the replacement? | -- | Go to Step 11 | -- |
10 | Replace the PCM/ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
