DESCRIPTION
While the generator is generating current, a duty signal is sent from terminal M of the generator to the ECM terminal ALT. The duty signal indicates density of field current flowing through the rotor coil of the generator, and the ratio of the duty signal is high when the voltage generated from the generator is high. The ECM uses this duty signal to determine if the generator is operating.
The ECM will detect a generator failure or an open malfunction of the circuit, if the duty signal is not output from terminal M of the generator, although the engine is running.
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0622 | No duty signal from terminal M of generator at engine running (1 trip detection logic) |
|
WIRING DIAGRAM
INSPECTION PROCEDURE
Tech Tips
If different DTCs related to different systems that have terminal E2 as the ground terminal are output simultaneously, terminal E2 may have an open circuit.
Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.
PROCEDURE
CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0622)
Connect an intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester ON.
Select the following menu items: Powertrain / Engine / DTC.
Read DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
GO TO DTC CHART Click here |
| A |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P0622)
Connect an intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester ON.
Select the following menu items: Powertrain / Engine / DTC / Clear.
Clear DTCs.
Start the engine.
Allow the engine to idle for 1 minute or more.
Select the following menu items: Powertrain / Engine / DTC.
Read DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
CHECK FOR INTERMITTENT PROBLEMS Click here |
| A |
|
CHECK HARNESS AND CONNECTOR (IGNITION SWITCH - GENERATOR - ECM)
Disconnect the D6 generator connector.
Turn the ignition switch to ON.
Measure the voltage of the generator connector.
| Standard voltage | ||||
|---|---|---|---|---|
|
Turn the ignition switch to OFF.
Disconnect the D1 ECM connector.
Measure the resistance of the harness side connectors.
| Standard resistance (Check for open) | ||||
|---|---|---|---|---|
|
| Standard resistance (Check for short) | ||||
|---|---|---|---|---|
|
Reconnect the generator connector.
Reconnect the ECM connector.
| NG |
|
REPAIR OR REPLACE HARNESS OR CONNECTOR |
| OK |
|
INSPECT GENERATOR ASSEMBLY (GENERATOR ROTOR)
Remove the generator assembly Click here.
Remove the generator rotor assembly Click here.
Measure the resistance between the slip rings of generator rotor.
| Standard resistance | ||||||
|---|---|---|---|---|---|---|
|
Measure the resistance between the slip ring and generator rotor assembly.
| Standard resistance | ||||
|---|---|---|---|---|
|
Inspect the slip rings of the generator rotor.
Check that the slip rings are not rough or scored.
Measure the slip ring diameter.
| Standard diameter |
|---|
| 14.2 to 14.4 mm (0.559 to 0.567 in.) |
| Minimum diameter |
|---|
| 14.0 mm (0.551 in.) |
| NG |
|
REPLACE GENERATOR ROTOR ASSEMBLY Click here |
| OK |
|
REPLACE GENERATOR ASSEMBLY
Replace the generator assembly Click here.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P0622) Click here |
REPLACE GENERATOR ROTOR ASSEMBLY
Replace the generator rotor assembly Click here.
| NEXT |
|
CHECK WHETHER DTC OUTPUT RECURS (DTC P0622)
Connect an intelligent tester to the DLC3.
Turn the ignition switch to ON and turn the tester ON.
Select the following menu items: Powertrain / Engine / DTC / Clear.
Clear DTCs.
Start the engine.
Allow the engine to idle for 1 minute or more.
Select the following menu items: Powertrain / Engine / DTC.
Read DTCs.
| Result | ||||||
|---|---|---|---|---|---|---|
|
| B |
|
END |
| A |
|
REPLACE ECM Click here