GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2005 🢒 GMC C Sierra - 2WD 🢒 Engine 🢒 Engine Electrical 🢒 DTC P0615

Circuit Description

The powertrain control module (PCM) uses output driver modules (ODMs) to control many functions of the engine. The ODMs supply the ground path for the PCM controlled device when the PCM commands the device ON. Each ODM is able to control several outputs. The PCM monitors the ODMs for circuit conditions that are incorrect for the commanded state of the ODM. If the PCM detects an improper circuit condition in the ODM that controls the starter relay, DTC P0615 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0615 Starter Relay Circuit

Conditions for Running the DTC

System voltage is between 8-16 volts.

Conditions for Setting the DTC
    • The PCM detects an improper voltage level on the output circuit that controls the starter relay.
    • The condition exists for at least 2 seconds.

Action Taken When the DTC Sets
    • The PCM will not illuminate the malfunction indicator lamp (MIL).
    • The PCM will store the conditions present when the DTC set as Fail Records data only.

Conditions for Clearing the MIL/DTC
    • The history DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
    • The DTC can be cleared by using the scan tool Clear DTC Information function.

Diagnostic Aids

Ignition system DTCs set with the ignition switch in the START position if the starter relay or the starter is inoperative. When the PCM enables starter operation, the PCM also initiates the diagnostic test routines for DTCs P0335, P0340, and P0385. If a condition exists which prevents the engine from cranking, the PCM will not receive signal input from the crankshaft position (CKP) and camshaft position (CMP) sensors, and the DTCs will set.

Reviewing the Fail Records vehicle mileage since the diagnostic test last failed may assist in diagnosing the condition. The information may help determine how often the condition that set the DTC occurs.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Listen for an audible click when the start 1 relay operates. Turn the ignition switch back and forth from the ON to START positions. Repeat this as necessary.

    2.

  2. This step tests for voltage at the coil side of the start 1 relay. The PCM IGN fuse supplies power to the coil side of the start 1 relay.

    3.

  3. This step verifies that the PCM is providing ground to the start 1 relay.

    4.

  4. This step tests if ground is constantly being applied to the start 1 relay.

Step

Action

Yes

No

Schematic Reference: Starting and Charging Schematics

Connector End View Reference: Engine Electrical Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. Turn the ignition back and forth from the ON to START positions.

Does the start 1 relay turn ON and OFF with each command?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the start 1 relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the battery positive voltage of the start 1 relay coil circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 4

Go to Step 8

4

  1. Connect a test lamp between the control circuit of the start 1 relay and the battery positive voltage of the start 1 relay coil circuit.
  2. Turn the ignition back and forth from the ON to START positions.

Does the test lamp turn ON and OFF with each command?

Go to Step 6

Go to Step 5

5

Test the control circuit of the start 1 relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the start 1 relay. 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

Inspect for poor connections at the powertrain control module (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 10

8

Repair the battery positive voltage circuit of the start 1 relay. Refer to Connector Repairs .

Did you complete the repair?

Go to Step 11

--

9

Replace the start 1 relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 11

--

11
  1. Review and record the scan tool Fail Records data.
  2. Use the scan tool in order to clear the DTC.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.
  4. Using the scan tool, observe the Specific DTC Information for DTC P0615 until the test runs.

Does the scan tool indicate that DTC P0615 failed this ignition?

Go to Step 2

System OK