Circuit Description
Output driver modules (ODMs) are used by the powertrain control module (PCM) in order to turn on many of the current-driven devices that are needed to control various functions. DTC P1585 set indicates that an improper voltage level has been detected on the output circuit which controls the stepper motor cruise control inhibit circuit.
Conditions for Setting the DTC
| • | The ignition is on. |
| • | An improper voltage level has been detected on the cruise control inhibit signal circuit. |
| • | The above conditions present for at least 30 seconds. |
Action Taken When the DTC Sets
| • | The PCM does not illuminate the malfunction indicator lamp (MIL). |
| • | 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 consecutive warm-up cycles have occurred without a malfunction. |
| • | The DTC can be cleared by using the scan tool Clear Info function or by disconnecting the PCM battery feed. |
Diagnostic Aids
Check for the following conditions:
| • | Inspect the PCM harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged, and faulty terminal to wire connections. |
| • | Inspect the wiring harness for damage. If the harness appears to be OK, disconnect the PCM, turn the ignition on, and observe a digital multimeter connected between the cruise control inhibit control circuit and ground at the PCM harness connector while moving the connectors and the wiring harnesses related to the SMCC module. A change in voltage indicates the location of the malfunction. |
Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
Test Description
Number(s) below refer to the step number(s) on the Diagnostic Table.
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Normally, ignition positive voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.
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Tests for a short to voltage on the signal circuit.
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This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform A Diagnostic System Check - Cruise Control? | -- | Go to Step 2 | |
Does the voltage measure near the specified value? | B+ | Go to Step 3 | Go to Step 4 | |
Does the test lamp illuminate? | -- | Go to Step 7 | Go to Step 5 | |
4 | Test the cruise control inhibit signal circuit for a open, high resistance or short to ground. Refer to Circuit Testing and 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 for the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 8 |
6 | Inspect for poor connections at the harness connector for the cruise control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 |
7 | Repair the short to voltage in the cruise control inhibit signal circuit. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 10 | -- |
|
Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Programming 3.4L or Powertrain Control Module Programming 3.8L in Engine Controls. Replace the PCM. Refer to Powertrain Control Module Replacement 3.4L or DTC P0172 3.8L in Engine Controls. Did you complete the repair? | -- | Go to Step 10 | -- | |
9 | Replace the cruise control module. Refer to Cruise Control Module Replacement . Did you complete the repair? | -- | Go to Step 10 | -- |
10 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
