GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The DTC P0616 Starter Relay Control Circuit Low Voltage diagnostic monitors the voltage signal that is sent from the ignition switch when starting the engine. When the engine is being cranked, battery voltage is applied to the powertrain control module (PCM). On a cold engine the PCM can increase the fuel injection volume and modify ignition timing when receiving the start signal. This signal passes through the transmission range (TR) switch or the clutch pedal position (CPP) switch. If this signal is not detected during engine cranking, the PCM will still allow the engine to start.

Condition for Running the DTC

The engine was started and is running.

Conditions for Setting the DTC

The engine is running but no starter signal was detected when the engine was cranking.

Action Taken When the DTC Sets

    • The PCM illuminates the malfunction indicator lamp (MIL) after 2 consecutive ignition cycles in which the diagnostic runs with the fault active.
    • The PCM records the operating conditions at the time the diagnostic fails. This information is stored in the Freeze Frame buffer.

Conditions for Clearing the MIL/DTC

    • The MIL turns OFF after 3 consecutively passing trips without a fault present.
    • A history DTC clears after 40 consecutive warm-up cycles without a fault.
    • Perform the scan tool Clear DTC Information function.

Test Description

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

  1. The Diagnostic System Check-Engine Controls prompts the technician to complete some basic checks and store the Freeze Frame data on the scan tool if applicable. This creates an electronic copy of the data taken when the fault occurred. The information is then stored in the scan tool for later reference.

  2. This step determines if a fault is present.

  3. This step checks for the correct voltage on the crank signal circuit. While the engine is cranking, the PCM crank signal terminal should have a voltage reading of 6 to 12 volts and after the engine is started, the PCM crank signal terminal should have a voltage reading of 0 volts.

  4. Clearing the DTCs by removing the DOME fuse also clears the PCM long term memory. Using the scan tool to clear DTCs leaves the long term memory active. DTC emitting diagnostics may not run to completion as expected unless the long term memory is cleared. Removal of the DOME fuse also clears the time display of the radio. The DTC P0616 diagnostic can be monitored on the scan tool under the Not Ran Since Code Cleared selection in the DTC Information menu. If a DTC P0616 appears in the Not Ran Since Code Cleared list, the DTC P0616 diagnostic has not yet run. When the DTC P0616 does not appear in the Not Ran Since Code Cleared list, the DTC P0616 diagnostic has run. If the MIL is NOT illuminated, and there is no Pending DTC Status in DTC Information, the DTC P0616 diagnostic has passed. The DTCs MUST be cleared in order to view the Current Status of the Not Ran Since Code Cleared list. DO NOT forget that the Not Ran Since Code Cleared list only indicates that the test has run, not whether the test passed or failed. The DTC Information screen must be checked for Current or Pending status, in order to determine the outcome of the diagnostic test involved.

Step

Action

Value(s)

Yes

No

Schematic Reference: Engine Controls Schematics

1

Did you perform the Diagnostic System Check-Engine Controls?

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Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Turn ON the ignition, leaving the engine OFF.
  2. Observe that the Starter Switch parameter on the scan tool indicates Released.
  3. Start the engine while observing the scan tool.

Did the scan tool indicate Cranking when starting the engine?

--

Go to Step 3

Go to Step 4

3

  1. Turn ON the ignition, leaving the engine OFF.
  2. Perform the scan tool Clear DTC Information function.
  3. Start the engine.
  4. Run the engine for 1 minute.
  5. Turn OFF the ignition.
  6. Wait 30 seconds and restart the engine again.

Is a Current or Pending DTC P0616 set?

--

Go to Step 4

Go to Intermittent Conditions

4

  1. Turn OFF the ignition.
  2. Disconnect the PCM electrical connectors.
  3. Turn ON the ignition, leaving the engine OFF.
  4. Place the gear selector in Park or Neutral.
  5. Crank the engine.
  6. Measure the start signal circuit voltage with a DMM while cranking the engine.

Was the start signal circuit voltage within the specified range while cranking the engine?

6-12 V

Go to Step 6

Go to Step 5

5

Repair the open in the crank signal circuit to the PCM. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 8

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6

  1. Test for an intermittent or a poor electrical connection at the PCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
  2. Repair as necessary.

Was a repair necessary?

--

Go to Step 8

Go to Step 7

7

Replace the PCM. Refer to Powertrain Control Module Replacement .

Did you complete the replacement?

--

Go to Step 8

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8

  1. Turn OFF the ignition.
  2. Remove the DOME fuse for 30 seconds.
  3. Install the DOME fuse.
  4. Reset the radio clock time. Refer to Radio/Audio System Description and Operation in Entertainment.
  5. Start the engine.
  6. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text or until the DTC P0616 diagnostic test has run.

Does the DTC run and pass?

--

Go to Step 9

Go to Step 2

9

With the 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

System OK