For 1990-2009 cars
Engine Controls Component Views
Oil Level, ETC, Cruise Control and Generator
OBD II Symbol Description Notice
Handling ESD Sensitive Parts Notice

### Circuit Description

The L-terminal circuit from the generator is a discrete circuit (a discrete circuit has no splices and only one source and one destination) into the PCM. The PCM applies ignition voltage to the generator L terminal circuit. A small amount of current flows from this circuit through the generator windings to create a magnetic field which starts the generator process. When the generator is at operating speed and producing voltage, a solid state switch for the L terminal circuit in the generator opens and the PCM detects that the initial startup current flow has stopped.

The PCM expects to detect low voltage on the L terminal circuit prior to the generator rotating at operating speed and conversely expects the circuit to be at ignition voltage potential when the generator is operational. When the PCM detects a fault (circuit shorted to ground, or circuit shorted to a voltage), the DTC sets.

### Conditions for Running the DTC

Engine operating.

### Conditions for Setting the DTC

The PCM detects an improper voltage on the generator L terminal circuit.

### Action Taken When the DTC Sets

• | The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.

• | The malfunction indicator lamp (MIL) will not illuminate.

• | The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

### Conditions for Clearing the DTC

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

• | 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.

• | 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/replacing the PCM. Ensure that the gaskets are installed correctly. The gaskets prevent water intrusion into the PCM.

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

• | A generator fault, such as a shorted output diode, malfunctioning regulator, open or shorted rotor, or open sense lead may cause a low battery charge. Refer to Charging System Check in Engine Electrical for further information and generator diagnosis.

• | Use a scan tool in order to diagnosis the generator circuits. A scan tool displays Generator L-Terminal Inactive when there is a concern with the L-terminal circuit.

• | Using the Freeze Frame and/or Failure Records data may aid in locating an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data can help determine how many miles since the DTC set. The Fail Counter and Pass Counter can also help determine how many ignition cycles the diagnostic reported a pass and/or a fail. Operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature etc.) that you observed. This will isolate when the DTC failed.

• | For an intermittent condition, refer to Symptoms .

### Test Description

The numbers below refer to the step numbers on the Diagnostic Table.

1. This step determines if a fault is present.

2. A poor connection at the generator causes no output.

Step | Action | Value(s) | 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. Start and idle the engine.
2. Install a scan tool.
3. Monitor the Generator L terminal parameter using a scan tool.

Does the scan tool display the Generator L terminal as Inactive?

--

Go to Step 3

Go to Diagnostic Aids

3 | Probe the Generator battery feed circuit using the Test Lamp J 35616-200 connected to ground. Refer to Probing Electrical Connectors in Wiring Systems. Does the test lamp illuminate? | -- | Go to Step 4 | Go to Charging System Check in Engine Electrical
4 |

1. Disconnect the electrical connector from the generator.
2. Start the engine.
3. Measure the voltage to ground at the generator harness connector terminal B using the DMM J 39200 . Refer to Measuring Voltage in Wiring Systems.

Is the voltage the same or more than the value specified?

10V

Go to Step 11

Go to Step 5

5 |

1. Turn OFF the ignition.
2. Disconnect the PCM connector C2. Refer to Powertrain Control Module Replacement/Programming .
3. Test for continuity from the generator circuit at the PCM harness connector to the B terminal of the generator harness connector using the DMM J 39200 . Refer to Testing for Continuity in Wiring Systems.

Does the DMM indicate continuity?

--

Go to Step 6

Go to Step 8

6 | Test for continuity from terminal B at the generator harness connector to battery ground using the DMM J 39200 . Refer to Testing for Continuity in Wiring Systems. Does the DMM indicate continuity? | -- | Go to Step 7 | Go to Step 9
7 | Repair the short to ground in the generator circuit. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 13 | --
8 | Repair the open/high resistance in the generator circuit. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Step 13 | --
9 |

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

Did you find and correct the condition?

--

Go to Step 13

Go to Step 10

10 | Important:: Program the replacement PCM. Refer to Powertrain Control Module Replacement/Programming . Replace the PCM. Is the action complete? | -- | Go to Step 13 | --
11 |

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

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

12 | Replace the generator. Refer to Generator Replacement in Engine Electrical. Is the action complete? | -- | Go to Step 13 | --
13 |

1. Select the Diagnostic Trouble Code (DTC) option and the Clear DTC Information 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 the vehicle within the conditions for running this DTC as specified in the supporting text, if applicable.

Does the scan tool indicate that this test ran and passed?

--

Go to Step 14

Go to Step 2

14 | 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 applicable DTC table | System OK