Engine General Information and Diagnosis: 1A-139
DTC P0625 / P0626: Generator Field Terminal Circuit Low / High
S7RS0B1104058
System and Wiring Diagram
Refer to “DTC P0620: Generator Control Circuit”.
Generator Control System Description
Refer to “Generator Control System Description”.
DTC Detecting Condition and Trouble Area
3 Generator control circuit check
1) Disconnect connector from generator and ECM with
ignition switch turned OFF.
2) Check for proper connection of wire terminal to
generator connector and to ECM connector.
3) If connections are OK, check generator control circuit for
the following.
• Resistance of generator control circuit wire between
generator connector and ECM connector is less than
1 Ω (continuity check)
• Resistance between generator control circuit wire of
generator connector and vehicle body ground is
infinity (ground circuit short check)
• Voltage between generator control circuit wire of
generator connector and vehicle body ground is 0 V
with ignition switch tuned ON (power circuit short
check)
Are they in good condition?
Go to Step 3. Repair or replace
defective wire.
4 Generator check
1) Check for generator output referring to “Generator Test
(Undercharged Battery Check) in Section 1J”.
Is check result satisfactory?
Go to Step 4. Repair or replace
generator.
5 Electric load current sensor check
1) Check for electric load current sensor output referring to
“Electric Load Current Sensor On-Vehicle Inspection in
Section 1C”.
Is check result satisfactory?
Substitute a known-
good ECM and recheck.
Replace electric load
current sensor.
Step Action Yes No
DTC detecting condition Trouble area
P0625:
Generator field coil duty is 0% (high voltage) for more than
specified time even through generator control is minimum
regulation (control duty 0%).
(1 driving cycle detection logic but MIL does not light up)
P0626:
Generator field coil duty is 100% (low voltage) for more than
specified time even through generator control is maximum
regulation (control duty 100%) or Generator field coil duty is 100%
(low voltage) when engine is starting.
(1 driving cycle detection logic but MIL does not light up)
• Generator and/or its circuit
•ECM