Starter Signal Circuit - Toyota 3VZ–FE Troubleshooting Manual

EG–400
DTC 43
CIRCUIT DESCRIPTION
When the engine is cranked, the intake air flow is slow, so fuel vaporization is poor. A rich mixture is therefore
necessary in order to achieve good startability. While the engine is being cranked, the battery voltage is applied
to terminal STA of the ECM. The starter signal is mainly used to increase the fuel injection volume for the starting
injection control and after–start injection control.
Code No. Diagnostic Trouble Code Detecting Condition
43 No starter signal to ECM
DIAGNOSTIC CHART DIAGNOSTIC CHART
HINT: This diagnostic chart is based on the premise that the engine is cranked normally. If the engine is not
cranked, proceed to the matrix chart of problem symptoms on page EG–344.
WIRING DIAGRAM
ENGINE TROUBLESHOOTING

Starter Signal Circuit

– CIRCUIT INSPECTION

Open or short in starter signal circuit.

Open or short in ignition switch or starter relay
circuit

ECM
(See page EG–344).
Trouble Area