DTC P1520: IMRC Drive Circuit Malfunction: Condition

PCM monitors intake manifold runner control (IMRC) circuit voltage. DTC is set when PCM terminal No. 42 voltage is less than 3 volts when IMRC valve is not operating. Possible causes are:

• Open or short in wiring between IMRC actuator harness connector terminal No. 1 and PCM harness connector terminal No. 42.
• Open in wiring between main relay terminal "D" and IMRC actuator harness connector terminal No. 2.
• Connector or terminal malfunction.
• IMRC malfunction.
• PCM malfunction.