Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Coolant thermostat (coolant
temperature below thermostat
regulating temperature)
Toyota Corolla (E120): Coolant thermostat (coolant temperature below thermostat regulating temperature)
Dtc p0128 coolant thermostat (coolant temperature below thermostat regulating temperature)
Hint
: this is the purpose of the ”thermostat” malfunction detection.
Other materials:
Check open circuit
For the open circuit in the wire harness in fig. 1, Perform
a resistance check in step (b) or a voltage check in step
(c) to locate the section.
Check the resistance.
Disconnect connectors a and c and measure the
resistance between them.
Resistance: 1 Ω or les ...
On–vehicle inspection
1. Inspect pressure switch no.1.
Magnetic clutch control:
inspect pressure switch operation.
Set on the manifold gauge set.
Connect the positive (+) lead from the ohmmeter to
terminal 4 and the negative (–) lead to terminal 1.
Check continuity between termin ...
Problem symptoms table
When the malfunction code is not confirmed in the diagnostic trouble code
check and the problem still can
not be confirmed in the basic inspection, proceed to this problem symptoms
tables and troubleshoot according
to the numbered order given below.
*: A/t only ...