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), this DTC will set.
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. 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
Diagnostic Starting Point - Engine Electrical
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.
For an intermittent condition, refer to
Symptoms
.
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
|
- Start and idle the engine.
- Install a scan tool.
- 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 connected
to ground. Refer to
Probing Electrical Connectors
in Wiring Systems.
Does the test lamp illuminate?
| --
|
Go to Step 4
| Go to
Diagnostic Starting Point - Engine Electrical
in
Engine Electrical
|
4
|
- Disconnect the electrical connector from the generator.
- Start the engine.
- Measure the voltage to ground at the generator harness connector
terminal B using the DMM. 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
|
- Turn OFF the ignition.
- Disconnect the PCM connector C2. Refer to
PCM Replacement/Programming
.
- Test for continuity from the generator circuit at the PCM harness
connector to the B terminal of the generator harness connector using the
DMM. 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. 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
|
- Inspect for poor connections at the PCM harness connector. Refer
to
Testing for Intermittent and Poor Connections
in Wiring Systems.
- 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
PCM Replacement/Programming
.
Replace the PCM.
Is the action complete?
| --
|
Go to Step 13
| --
|
11
|
- Inspect for poor connections at the generator electrical connector.
Refer to
Testing for Intermittent and Poor Connections
in Wiring Systems.
- 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
|
- Select the Diagnostic Trouble Code (DTC) option and the Clear
DTC Information option using the scan tool.
- Idle the engine at the normal operating temperature.
- Select the Diagnostic Trouble Code (DTC) option and the Specific
DTC option, then enter the DTC number using the scan tool.
- 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 the applicable DTC table
| System OK
|
