DTC P0651 Sensor Reference Voltage 2 Circuit (4JJ3 with DPD)

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

The ECM also supplies 5 V power to the following sensors through 5 V reference circuit 8.

  • FRP sensor
  • CMP sensor
  • Exhaust gas temperature sensor 2 (Front of oxidation catalyst)

5 V reference circuits 2 and 8 are independent of each other outside the ECM but share the bus inside the ECM. Therefore, whole 5 V reference circuits 2 and 8 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 8, 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 9 to 16 V.
  • The ignition switch is ON.

Condition for setting the DTC

  • The ECM detects that the voltage of 5 V reference circuit 2 or 8 is 4.5 V or less, or 5.5 V or more.

3. Action taken when DTC P0651 sets

  • The ECM illuminates the MIL. Refer to Action taken when DTC sets - Type A.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) DTC type definitions".

  • 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 cruise control.
  • The ECM assumes a default Exhaust gas temperature sensor 2 (front of oxidation catalyst) value.
  • The ECM assumes a default FRP sensor value.

4. Condition for clearing DTC P0651

  • Refer to Conditions for clearing the MIL/DTC - Type A or Type B.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) DTC type definitions".