For 1990-2009 cars

### Circuit Description

The Run/Crank relay is controlled by the body control module (BCM). The Run/Crank relay contacts are supplied a hot at all times from the fuse block underhood. The relay supplies power to several components when the vehicle is in the RUN or CRANK power mode. This signal is labeled Ignition 1. When the ignition switch is placed in the RUN or CRANK position, the BCM will receive a Run/Crank signal from the ignition switch and turn ON the Run/Crank relay. When the ignition switch is in the OFF position, the BCM will turn OFF the Run/Crank relay. The powertrain control module (PCM) compares the Run/Crank relay output signal with the BCM Class 2 serial data power mode message. If the ignition 1 voltage signal and the power mode message do not match for an allotted time, the PCM will disable the fuel injectors and DTC P2535 will set.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2535 Ignition 1 Switch Circuit High Voltage

DTC Symptom | DTC Symptom Descriptor
--- | ---
00 | No Additional Information

### Conditions for Running the DTC

• | The vehicle is in PARK or NEUTRAL.

• | The ignition switch is OFF.

### Conditions for Setting the DTC

The ignition 1 voltage signal is higher than normal for more than 7 seconds.

### Action Taken When the DTC Sets

• | The control module stores the DTC information into memory when the diagnostic runs and fails.

• | The malfunction indicator lamp (MIL) will not illuminate.

• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.

• | The driver information center, if equipped, may display a message.

### Conditions for Clearing the DTC

• | A current DTC Last Test Failed clears when the diagnostic runs and passes.

• | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.

• | Clear the DTC with a scan tool.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: Power Distribution Schematics Connector End View Reference: Master Electrical Component List
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn OFF the ignition.
2. Disconnect the Run/Crank relay.
3. Connect a test lamp between the Run/Crank voltage circuit on the powertrain control module (PCM) side of the relay and a good ground.

Does the test lamp illuminate?

--

Go to Step 4

Go to Step 3

3 | Connect a test lamp between the Run/Crank voltage circuit on the body control module (BCM) side of the relay and a good ground. Does the test lamp illuminate? | -- | Go to Step 5 | Go to Step 8
4 | Test the Run/Crank voltage circuit between the PCM and the Run/Crank relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 6
5 | Test the Run/Crank voltage circuit between the BCM and the Run/Crank relay for a short to voltage. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 7
6 | Test for an intermittent and for a poor connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 9
7 | Test for an intermittent and for a poor connection at the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 11 | Go to Step 10
8 | Replace the Run/Crank relay. Refer to Relay Replacement . Did you complete the replacement? | -- | Go to Step 11 | --
9 | Replace the PCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | --
10 | Replace the BCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 11 | --
11 |

1. Clear the DTCs with a scan tool.
2. Turn OFF the ignition for 30 seconds.
3. Start the engine.
4. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records.

Did the DTC fail this ignition?

--

Go to Step 2

Go to Step 12

12 | With a scan tool, observe the stored information, Capture Info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK