GM Service Manual Online
For 1990-2009 cars only

Object Number: 226858  Size: MF
Engine Controls Components
Power, Ground and MIL
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

Circuit Description

Output Driver Modules (ODMs) are used by the PCM to turn on many of the current-driven devices that are needed to control various engine and Transaxle functions. Each ODM is capable of controlling up to 7 separate outputs by applying ground to the device which the PCM is commanding ON. Unlike the Quad Driver Modules (QDMs) used in prior model years, ODMs have the capability of diagnosing each output circuit individually. DTC P0650 set indicates an improper voltage level on the output circuit that controls the Malfunction Indicator Lamp (MIL).

Conditions for Running the DTC

Ignition is ON.

Conditions for Setting the DTC

    • An improper voltage level has been detected on the output circuit which controls the Malfunction Indicator Lamp (MIL).
    • Above conditions for at least 30 seconds.

Action Taken When the DTC Sets

    • The PCM will illuminate the malfunction indicator lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
    • The PCM will store conditions which were present when the DTC set as Freeze Frame and Failure Records data.

Conditions for Clearing the MIL/DTC

    • The PCM will turn OFF the MIL during the third consecutive trip in which the diagnostic has been run and passed.
    • 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.

Diagnostic Aids

Check for the following conditions:

    • Poor connection at the PCM.
        Inspect harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and poor terminal to wire connection.
    • Damaged harness.
        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 MIL control circuit and ground at the PCM harness connector while moving connectors and wiring harnesses related to the MIL. A change in voltage will indicate the location of the malfunction.

Reviewing the Freeze Frame/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.

  1. Normally, ignition feed voltage should be present on the control circuit with the PCM disconnected and the ignition turned ON.

  2. Tests for a shorted component or a short to B+ on the control circuit. Either condition would result in a measured current of over 500 milliamps. Also tests for a component that is causing an open circuit while being operated, resulting in a measured current of 0 milliamps.

  3. Tests for a short to voltage on the control circuit.

  4. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is replaced, the new PCM must be programmed.

DTC P0650 - MIL Control Circuit

Step

Action

Value(s)

Yes

No

1

Did you perform the Powertrain On-Board Diagnostic (OBD) System Check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2

  1. Turn OFF the ignition.
  2. Disconnect the PCM.
  3. Turn ON the ignition.
  4. Measure the voltage on the MIL control circuit using a J 39200 Digital Multimeter that is connected to a good ground.

Does the voltage measure at or near the specified value?

B+

Go to Step 3

Go to Step 6

3

  1. Measure the current on the MIL control circuit using a DMM.
  2. Observe the DMM for at least 2 minutes.

Does the current remain within the specified range?

0.05-0.5 Amps

(50-500 mA)

Go to Step 11

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Leave the PCM disconnected.
  3. Disconnect the instrument panel.
  4. Turn ON the ignition.
  5. Measure the voltage on the MIL control circuit using a DMM that is connected to a good ground.

Does the voltage measure at or near the specified value?

0 V

Go to Step 10

Go to Step 5

5

Repair short to voltage in the MIL control circuit. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 15

--

6

Inspect the ignition feed fuse for the instrument panel indicators.

Is the fuse open?

--

Go to Step 7

Go to Step 8

7

  1. Repair the short to ground in ignition feed circuit for the instrument panel indicators. Refer to Wiring Repairs .
  2. Replace the fuse.

Did you complete the repair?

--

Go to Step 15

--

8

  1. Disconnect the instrument cluster.
  2. Turn ON the ignition.
  3. Measure the voltage on the ignition feed circuit for the instrument cluster indicators using a DMM that is connected to a good ground.

Does the voltage measure at or near the specified value?

B+

Go to Step 9

Go to Step 13

9

Test the MIL control circuit for an open or a short to ground. Refer to Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 10

10

Inspect the MIL control circuit and the instrument panel indicators ignition feed circuit for a faulty connection at the instrument panel and the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Instrument Cluster Schematic References in Body and Accessories

11

  1. Turn OFF the ignition.
  2. Reconnect the PCM.
  3. Disconnect the instrument cluster.
  4. Turn ON the ignition.
  5. Connect a J 35616-200 Test Lamp between the MIL control circuit and the I/P ignition feed circuit.
  6. With a scan tool, command the MIL ON and OFF.

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

--

Go to Diagnostic Aids

Go to Step 12

12

Inspect the MIL control circuit for a faulty connection at the PCM. Refer to Intermittents and Poor Connections Diagnosis and Connector Repairs .

Did you find and correct the condition?

--

Go to Step 15

Go to Step 14

13

Repair the open in the ignition feed circuit to the I/P indicators. Refer to Wiring Repairs .

Did you complete the repair?

--

Go to Step 15

--

14

Important:: The replacement PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Replace the PCM.

Did you complete the replacement?

--

Go to Step 15

--

15

  1. Use the scan tool in order to record Fail Records and clear the DTCs
  2. Operate the vehicle within Fail Records conditions.

Does the DTC reset?

--

Go to Step 2

System OK