DTC P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)
HINT: This DTC relates to the thermostat.
DESCRIPTION This DTC is set when the Engine Coolant Temperature (ECT) does not reach 75C (167F) despite sufficient engine warm-up time
DTC No. |
DTC Detection Condition |
Trouble Area |
P0128 |
Conditions (a), (b) and (c) are met for 5 seconds (2 trip
detection logic):
|
|
MONITOR DESCRIPTION
The ECM estimates the ECT based on the starting temperature, engine loads, and engine speeds. The ECM then compares the estimated temperature with the actual ECT. When the estimated ECT reaches 75C (167F), the ECM checks the actual ECT. If the actual ECT is less than 75C (167F), the ECM interprets this as a malfunction in the thermostat or the engine cooling system and sets the DTC.
MONITOR STRATEGY
TYPICAL ENABLING CONDITIONS
TYPICAL MALFUNCTION THRESHOLDS
INSPECTION PROCEDURE
HINT: Read freeze frame data using the intelligent tester. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air-fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction
1 CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0128)
Result
HINT: If any DTCs other than P0128 are output, troubleshoot those DTCs first.
2 CHECK COOLING SYSTEM
3 INSPECT THERMOSTAT
Standard: 80 to 84C (176 to 183F)
HINT: In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.
REPLACE ECM
Fold Lock Switch Circuit
DESCRIPTION
Each of the left and right seats has a fold lock switch that detects the lock
condition of the seat legs and
floor when the seat is in the stowed state. If the fold lock switch detects an
unlock condition, the 3rd SEAT
indicator on the combination meter will come on.
WIRING DIAGR ...
Diagnostic trouble code chart
Look for output Diagnostic Trouble Codes (DTCs) (from the
DTC checks) in the appropriate section's Diagnostic Trouble
Code Chart. Use the chart to determine the trouble area and
the proper inspection procedure. A description of each of the
chart's columns is shown in the table below.
Ite ...
Air Mix Damper Control Servo Motor Circuit (Passenger Side)
DESCRIPTION
The air mix control servo motor (air mix damper servo sub-assembly) is
controlled by the A/C amplifier.
The air mix control servo motor moves the air mix damper by rotating (normal,
reverse) with electrical
power from the A/C amplifier.
This adjusts the mix ratio of the air t ...