DTC P0651 (Flash Code 56) Sensor Reference Voltage 2 Circuit (RZ4E-TC)

1. DTC P0651 description

The ECM supplies 5 V power to the following sensors via 5 V reference circuit 2.

  • Accelerator pedal position sensor 2
  • Barometric pressure sensor
  • IAT sensor

Also, the ECM supplies 5 V reference to the following sensors through 5 V reference circuit 5.

  • FRP sensor
  • CMP sensor

5 V reference circuits 2 and 5 are independent of each other outside the ECM but share the bus inside the ECM. Therefore, all of 5 V reference circuits 2 and 5 may be affected by a short circuit in one of the sensor 5 V reference circuits. The ECM monitors the voltage of 5 V reference circuits 2 and 5, and if it detects that the voltage is excessively low or high, the DTC is set.

2. Condition for setting DTC P0651

Condition for running the DTC

  • The battery voltage is 8 to 16 V.
  • DTC P060B is not set.

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC P060B (Flash Code 36) Internal Control Module A/D Processing Performance".

Condition for setting the DTC

  • The ECM detects that the voltage of 5 V reference circuit 2 or 5 is 4.5 V or less, or 5.5 V or more.

3. Action taken when DTC P0651 sets

  • Euro4: The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type A (Euro4).
  • Except Euro4: The ECM illuminates the check engine warning light. Refer to Action taken when DTC sets - Type A (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".

  • The ECM assumes a default barometric pressure value.
  • The ECM assumes a default fuel rail pressure value.
  • The ECM assumes a default IAT value.
  • The ECM limits the fuel injection quantity.
  • The ECM inhibits engine startup.
  • The ECM inhibits pre-injection.
  • The ECM inhibits the EGR control.
  • The ECM inhibits the turbocharger control.
  • The ECM limits the fuel rail pressure.
  • The ECM inhibits the cruise control.

4. Condition for clearing DTC P0651

  • Euro4: Refer to Condition for clearing the MIL/DTC - Type A or Type B (Euro4).
  • Except Euro4: Refer to Condition for clearing the check engine warning light/DTC - Type A or Type B (Except Euro4).

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) DTC type definitions".