The powertrain control module (PCM) has detected that voltage on the fuel metering control circuit for the distributor-type injection pump (or unit injector system) exceeds the calibrated upper limit. This circuit controls an electromagnetic metering valve that regulates fuel delivery; a "High" reading typically indicates a short to voltage, an open circuit, or a faulty actuator preventing proper fuel quantity regulation.
The control wire between the PCM and injection pump may be chafed, pinched, or corroded, causing it to short to battery voltage or open, resulting in a high voltage reading at the PCM.
The electromagnetic actuator mounted on the injection pump may have an internal short, open coil, or resistance out of specification, causing the PCM to detect an incorrect voltage drop across the circuit.
Corroded, loose, or moisture-contaminated connectors at the injection pump or PCM can introduce excessive resistance or intermittent contact that alters circuit voltage.
Internal mechanical binding or seizure of the pump's metering components can cause the control valve to stall or draw abnormal current, affecting the electrical circuit characteristics.
Rarely, the PCM's internal output driver for the metering valve may malfunction and hold the circuit high; this should only be considered after wiring and actuator integrity are verified.
No. This fault directly affects fuel metering and can cause engine stalling, inability to restart, or potential damage to emissions components; the vehicle should not be driven until repaired.
Not necessarily. While the pump-mounted metering valve could be faulty, the code frequently results from wiring harness issues or connector corrosion that can be repaired without replacing the pump assembly.
Usually not. PCM failure is statistically rare for this code. Most cases are resolved by repairing wiring shorts or replacing the metering valve. The PCM should only be suspected after exhaustive testing proves the wiring and actuator are flawless.
It indicates the code applies to distributor-type injection pumps (with cam-driven rotors) or unit injector systems where fuel metering is electronically controlled relative to engine position.