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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2004 🢒 XLR 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 DTC P0615

Circuit Description

The engine control module (ECM) supplies a ground path for the starter relay when start enable has been requested. The ECM monitors this circuit for conditions that are incorrect for the commanded state. If the ECM detects an improper circuit condition, starter relay DTC P0615 will set.

Conditions for Running the DTC

System voltage is between 9 and 16 volts.

Conditions for Setting the DTC
    • The ECM 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 ECM will not illuminate the malfunction indicator lamp (MIL)
    • The ECM 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 ECM enables starter operation, the ECM also initiates the diagnostic test routines for DTCs P0335, P0340, and P0385. If a condition exists which prevents the engine from cranking, the ECM will not receive signal input from the CKP and 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 Crank relay operates. Press the ignition switch back and forth from the ON to START positions. Repeat this as necessary.

    2.

  2. Tests for voltage at the coil side of the Crank relay. The ECM IGN fuse supplies power to the coil side of the Crank relay.

    3.

  3. Verifies that the ECM is providing ground to the Crank relay.

    4.

  4. Tests if ground is constantly being applied to the Crank relay.

Step

Action

Yes

No

Schematic Reference: Starting and Charging Schematics

Connector End View Reference: Power and Grounding Connector End Views in Wiring Systems

1

Did you perform the Vehicle Diagnostic System Check?

Go to Step 2

Go to Diagnostic Starting Point - Computer/Integrating Systems in Computer/Integrating Systems

2

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

Does the Crank relay click with each command?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the Crank relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the battery positive voltage of the Crank 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 Crank relay and the battery positive voltage of the Crank 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 Crank relay for a short to voltage or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the Crank relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

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 (ECM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

Repair the battery positive voltage circuit of the Crank relay. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 11

--

9

Replace the Crank relay.

Did you complete the replacement.

Go to Step 11

--

10

Important: The replacement ECM must be programmed.

Replace the ECM. Refer to Engine Control Module Replacement in Engine Controls-4.6L (LH2).

Did you complete the replacement?

Go to Step 11

--

11
  1. Review and record scan tool Fail Records data.
  2. Clear DTCs.
  3. Operate vehicle within Fail Records conditions as noted.
  4. Using a scan tool, monitor the Specific DTC Information for DTC P0615.

Does the scan tool indicate DTC P0615 failed this ignition?

Go to Step 2

System OK