PrecautionsDTC “c28” (p1655): secondary throttle
valve actuator (stva) malfunction
Detected condition and possible cause
Detected condition
Possible cause
The operation voltage does not reach the stva.
Ecm does not receive communication signal from the
stva. Stva can not operate properly or its motor locked
Stva malfunction.
...
Regulator / rectifier inspection
Inspect the regulator/rectifier in the following procedures:
turn the ignition switch off.
Disconnect the regulator/rectifier couplers. Refer to “regulator /
rectifier removal and installation” .
Measure the voltage between the terminals using the multi-circuit
tester ...
Dtc “c36” (p1764), “c37” (p1765), “c38” (p1766) or “c39” (p1767): secondary
fuel injector circuit
malfunction
Detected condition and possible cause
Detected condition
Possible cause
Some failure exists in the fuel injector signal in a high
load, high revolution condition.
Injector circuit open or short.
Injector malfunction.
Ecm malfunction.
...