DTC P0650 Malfunction Indicator Lamp (MIL) Control Circuit. Oldsmobile Shelby Series 1 1999

For 1990-2009 cars
Engine Controls Components
Power, Ground and MIL
OBD II Symbol Description Notice
Powertrain Control Module Connector End Views
Handling ESD Sensitive Parts Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

A voltage is supplied directly to the malfunction indicator lamp (MIL). The powertrain control module (PCM) controls the lamp by grounding the control circuit via an internal switch called a driver. The primary function of the driver is to supply the ground for the component being controlled. Each driver has a fault line which is monitored by the PCM. When the PCM is commanding a component ON, the voltage of the control circuit should be near 0 volts. When the PCM is commanding the control circuit to a component OFF, the voltage potential of the circuit should be near battery voltage. If the fault detection circuit senses a voltage other than what is expected, the fault line status will change causing the DTC to set.

### Conditions for Running the DTC

• | Engine speed is more than 400 RPM.

• | The ignition voltage is between 6.0 volts and 18.0 volts.

### Conditions for Setting the DTC

• | The PCM detects that the commanded state of the driver and the actual state of the control circuit do not match.

• | The conditions are present for a minimum of 5 seconds.

### Action Taken When the DTC Sets

• | The PCM stores DTC P0650 in memory on the second consecutive ignition cycle that the diagnostic runs and fails.

• | The MIL will not illuminate.

• | The PCM records the operating conditions at the time the diagnostic fails. The first time the diagnostic fails, the PCM stores this information in the Failure Records. If the diagnostic reports a failure on the second consecutive ignition cycle, the PCM records the operating conditions at the time of the failure. The PCM writes the conditions to the Freeze Frame and updates the Failure Records.

### Conditions for Clearing the DTC

• | A History DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.

• | A last test failed, or current DTC, will clear when the diagnostic runs and does not fail.

• | Use a scan tool in order to clear the DTC.

### Diagnostic Aids

Important:

• | Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing or replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.

• | For any test that requires probing the PCM or a component harness connector, use the J 35616 connector test adapter kit. Using this kit prevents damage to the harness and component terminals. Refer to Using Connector Test Adapters in Wiring Systems.

• | The following may cause an intermittent:

- | Poor connections -- Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.

- | Corrosion

- | Mis-routed harness

- | Rubbed through wire insulation

- | Broken wire inside the insulation

• | If the ignition feed circuit is suspected of being open, inspect for lamps on the same circuit not illuminating.

• | For an intermittent condition, refer to Symptoms .

### Test Description

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

1. Command both the ON and the OFF states. Repeat the commands as necessary.

2. If you do not find trouble in the control circuit or the connection at the PCM, the PCM may be faulty. However, this is an extremely unlikely failure.

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

Important: If the instrument panel (IP) is completely inoperative, refer to A Diagnostic System Check - Instrument Cluster in Instrument Panel, Gauges and Console.

1. Turn ON the ignition leaving the engine OFF.
2. Command the indicator lamp ON and OFF using the scan tool.

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

--

Go to Diagnostic Aids

Go to Step 3

3

1. Turn OFF the ignition.
2. Disconnect the PCM connector C2 located on the opposite side of the manufacturer logo Refer to Powertrain Control Module Replacement/Programming .
3. Turn ON the ignition leaving the engine OFF.

Is the indicator lamp OFF?

--

Go to Step 4

Go to Step 5

4 | Probe the indicator lamp control circuit in the PCM harness connector with a fused jumper wire connected to ground. Refer to Using Fused Jumper Wires in Wiring Systems. Is the indicator lamp ON? | -- | Go to Step 6 | Go to Step 7
5 | Repair the short to ground in the indicator lamp control circuit. Refer to Wiring Repairs in Wiring Systems. Is the action complete? | -- | Go to Step 9 | --

6

1. Inspect for poor connections at the PCM. Refer to Intermittents and Poor Connections Diagnosis in Wiring Systems.
2. If you find a poor connection, repair the terminal as necessary. Refer to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

7

Inspect for the following conditions:

• | Faulty indicator lamp

• | Open ignition feed to the indicator lamp

• | Control circuit open or shorted to B+

Did you find and correct the condition?

--

Go to Step 9

--

8 | Important:: The replacement PCM must be programmed. Replace the PCM. Refer to Powertrain Control Module Replacement/Programming . Is the action complete? | -- | Go to Step 9 | --

9

1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC option using the scan tool.
2. Idle the engine at the normal operating temperature.
3. Select the Diagnostic Trouble Code (DTC) option and the Specific DTC option, then enter the DTC number using the scan tool.
4. Operate vehicle within the Conditions for Running the DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test passed?

--

Go to Step 10

Go to Step 2

10 | Select the Capture Info option and the Review Info option using the scan tool. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to the applicable DTC table | System OK