Circuit Description
The cruise control resume/accel switch is an input to the engine control module (ECM). The ECM monitors the cruise control resume/accel switch signal circuit in order to detect when the driver has requested to accelerate the set vehicle speed or to resume the cruise control system. The ECM module detects a voltage signal on the cruise control resume/accel switch signal circuit when the switch is applied. This DTC sets if the ECM detects that voltage is present on the cruise control resume/accel switch signal circuit for longer than 60 seconds.
Conditions for Running the DTC
The ignition is ON.
The cruise control switch is ON.
Conditions for Setting the DTC
The ECM detects that the resume/accel switch is applied for longer than 60 seconds.
Action Taken When the DTC Sets
| • | The ECM stores the DTC information into memory when the diagnostic runs and fails. |
| • | The malfunction indicator lamp (MIL) will not illuminate. |
| • | The ECM records the operating conditions at the time the diagnostic fails. The ECM stores this information in the Failure Records. |
| • | The cruise control system is disabled. |
Conditions for Clearing the MIL/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 MIL/DTC. |
Diagnostic Aids
Ensure that the resume/accel switch is not stuck or sticking in the engaged position.
For an intermittent condition, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The number below refers to the step number on the diagnostic table.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference : Cruise Control Schematics Connector End View Reference: Engine Control Module Connector End Views in Engine Controls - 7.8L | |||
1 | Did you perform the Diagnostic System Check - Cruise Control? | Go to Step 2 | |
Does the Cruise Resume/Accel. Switch parameter display On? | Go to Step 3 | Go to Diagnostic Aids | |
3 |
Does the Cruise Resume/Accel. Switch parameter display On? | Go to Step 4 | Go to Step 5 |
4 | Test the cruise control resume/accel switch signal circuit for a short to voltage. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
5 | Inspect for poor connections at the harness connector of the multifunction switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
6 | Inspect for poor connections at the harness connector of the ECM. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
7 | Replace the multifunction switch. Refer to Turn Signal Multifunction Switch Replacement in Steering Wheel and Column. Did you complete the replacement? | Go to Step 9 | -- |
8 |
Important: Program the replacement ECM. Replace the ECM. Refer to Engine Control Module Replacement/Restore Fuel Rate Data in Engine Controls - 7.8L. Did you complete the replacement? | Go to Step 9 | -- |
9 |
Does the DTC reset? | Go to Step 2 | System OK |
