DTC P0650 Malfunction Indicator Lamp (MIL) Control Circuit. Buick GL7 (Export) 2000

For 1990-2009 cars

### Circuit Description

Output driver modules (ODMs) are used by the powertrain control module (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. 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

• | The ignition is ON.

• | Ignition voltage is between 9.0 and 18.0 volts.

### Conditions for Setting the DTC

• | An improper voltage level has been detected on the MIL control circuit.

• | The above conditions are present for at least 30 seconds.

### Action Taken When the DTC Sets

• | The PCM will not illuminate the MIL.

• | The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

### Conditions for Clearing the MIL/DTC

• | A 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 Info function or by disconnecting the PCM battery feed.

### Diagnostic Aids

Inspect for the following conditions:

• | A poor connection at the PCM. Inspect the harness connectors for the following conditions:

- | Backed-out terminals

- | Improper mating

- | Broken locks

- | Improperly formed or damaged terminals

- | Poor terminal-to-wire connections

• | Use a corresponding mating terminal to test for the proper terminal tension.

• | A 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 DMM connected between the MIL control circuit and ground at the PCM harness connector while moving the connectors and the wiring harnesses related to the MIL. A change in the voltage indicates the location of the malfunction.

Reviewing the Failure 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

The numbers below refer to the step numbers 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. Checks for a short to voltage on the control circuit.

3. This vehicle is equipped with a PCM which utilizes an electrically erasable programmable read-only memory (EEPROM). If the PCM is replaced, the new PCM must be programmed.

#### DTC P0650 - MIL Control Circuit

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Powertrain On-Board Diagnostic (OBD) System Check ? | -- | 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, leaving the engine OFF.
4. Connect a DMM between the MIL control circuit and ground.

Is the voltage near the specified value?

B+

Go to Step 3

Go to Step 5

3

1. Turn OFF the ignition.
2. Disconnect the instrument panel cluster (IPC). Leave the PCM disconnected.
3. Turn ON the ignition, leaving the engine OFF.
4. Connect a DMM between the MIL control circuit and ground.

Is the voltage near the specified value?

0.0 V

Go to Step 9

Go to Step 4

4 | Repair a short to voltage in the MIL control circuit. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | --
5 | Check the ignition feed fuse for the IPC indicators. Is the fuse open? | -- | Go to Step 6 | Go to Step 7

6

1. Repair a short to ground in ignition feed circuit for the IPC indicators. Refer to Wiring Repairs in Wiring Systems.
2. Replace the fuse.

Did you find and correct the condition?

--

Go to Step 13

--

7

1. Disconnect the instrument panel cluster.
2. Turn ON the ignition.
3. Connect a DMM between the ignition feed circuit and ground.

Is the voltage near the specified value?

B+

Go to Step 8

Go to Step 11

8

1. Inspect the MIL control circuit for an open or a short to ground.
2. If a problem is found, repair the MIL control circuit. Refer to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

9

1. Inspect the MIL control circuit and the ignition feed circuit of the instrument panel indicators for a poor connection at the IPC and at the PCM.
2. If a problem is found, replace the loose terminals. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges, and Console

10

1. Inspect the MIL control circuit for a poor connection at the PCM.
2. If a problem is found, replace the loose terminal. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

11 | Repair the open in the ignition feed circuit to the IPC indicators. Refer to Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 13 | --
12 | Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Did you complete the replacement ? | -- | Go to Step 13 | --

13

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Failure Record conditions.

Does the DTC reset ?

--

Go to Step 2

System OK