Circuit Description
The powertrain control module (PCM) removes the ground from the cruise control inhibit signal circuit when it determines that conditions exist for which cruise control should not be enabled. The PCM also monitors the voltage on this circuit in order to determine if a fault exists.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1585 Cruise Control Inhibit Output Circuit
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The system voltage is between 9-16 volts. |
Conditions for Setting the DTC
| • | The PCM detects that an improper voltage exists on the cruise control inhibit signal circuit. |
| • | The above condition is present for at least 30 seconds. |
Action Taken When the DTC Sets
The PCM stores the conditions which were present when the DTC set as Fail Records data only. This information is not stored as Freeze Frame data.
Conditions for Clearing the MIL/DTC
| • | A history DTC clears after 40 malfunction-free warm-up cycles. |
| • | The PCM receives the clear code command from the scan tool. |
Test Description
The number below refers to the step number on the Diagnostic Table.
Step | Action | Values | Yes | No |
|---|---|---|---|---|
Schematic Reference: Cruise Control Schematics | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
Does the voltage measure near the specified value? | B+ | Go to Step 5 | Go to Step 3 | |
3 |
Does the test lamp illuminate? | -- | Go to Step 4 | Go to Step 7 |
4 | Test the cruise control inhibit signal circuit for an open, for a high resistance, for a short to voltage, or for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 6 |
5 | Inspect for poor connections at the harness connector of the PCM. 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 10 | Go to Step 8 |
6 | Inspect for poor connections at the harness connector of the cruise control module. 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 10 | Go to Step 9 |
7 | Repair the open, the high resistance, or the short to ground in the ignition 3 voltage circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 10 | -- |
8 | Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 10 | -- |
9 | Replace the cruise control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, programming. Did you complete the replacement? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
