P0652-SENSOR REFERENCE VOLTAGE 2 TOO LOW
For a complete wiring diagram Refer to Section 8W
- When Monitored:
With the ignition on.
- Set Condition:
The ECM detects low voltage on the Sensor Supply 2 circuit for 0.16 second
| Possible Causes |
| INTERMITTENT DTC |
| CRANKSHAFT POSITION SENSOR |
| INTAKE AIR TEMPERATURE/BOOST PRESSURE SENSOR |
| ACCELERATOR PEDAL POSITION SENSOR |
| MASS AIRFLOW SENSOR |
| 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND |
| ENGINE CONTROL MODULE (ECM) |
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
Theory of Operation
The ECM contains 2 internal 5–Volt Sensor Supply sources. Each 5–Volt Supply source is split into parallel circuits to provide 5 volts to multiple sensors. Sensor Supply 2 provides 5 volts to the Crankshaft Position Sensor, the Boost Pressure Sensor, Accelerator Pedal Position Sensor No. 2, and the Mass Airflow Sensor.
Diagnostic Test
1. CHECK FOR ACTIVE DTCTurn the ignition on.
With the scan tool, erase ECM DTCs.
Turn the ignition off for 10 seconds.
Turn the ignition on.
With the scan tool, select View DTCs.
Is the status Active for this DTC?
Yes
- Go To2
No
- Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
2. CRANKSHAFT POSITION SENSOR
Turn the ignition off.
Disconnect the Crankshaft Position Sensor harness connector.
Turn the ignition on.
Measure the voltage of the (K853) Crankshaft Position Sensor 5 Volt Supply circuit at the Crankshaft Position Sensor harness connector.
Is the voltage above 4.6 volts?
Yes
- Replace the Crankshaft Position Sensor.
- Perform the ECM VERIFICATION TEST. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go To3
3. INTAKE AIR TEMPERATURE/BOOST PRESSURE SENSOR
Turn the ignition off.
Disconnect the Intake Air Temperature/Boost Pressure Sensor harness connector.
Turn the ignition on.
Measure the voltage of the (K854) Boost Pressure Sensor 5 Volt Supply circuit at the Intake Air Temperature/Boost Pressure Sensor harness connector.
Is the voltage above 4.6 volts?
Yes
- Replace the Intake Air Temperature/Boost Pressure Sensor.
- Perform the ECM VERIFICATION TEST. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go To4
4. ACCELERATOR PEDAL POSITION SENSOR
Turn the ignition off.
Disconnect the Accelerator Pedal Position harness connector.
Turn the ignition on.
Measure the voltage of the (K854) Accelerator Pedal Position Sensor No. 2 5 Volt Supply circuit at the Accelerator Pedal Position Sensor harness connector.
Is the voltage above 4.6 volts?
Yes
- Replace the Accelerator Pedal Position Sensor.
- Perform the ECM VERIFICATION TEST. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go To5
5. MASS AIRFLOW SENSOR
Turn the ignition off.
Disconnect the Mass Airflow Sensor harness connector.
Turn the ignition on.
Measure the voltage of the (F855) Mass Airflow Sensor 5 Volt Supply circuit at the Mass Air Flow Sensor harness connector.
Is the voltage above 4.6 volts?
Yes
- Replace the Mass Airflow Sensor.
- Perform the ECM VERIFICATION TEST. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Go To6
6. 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
Turn the ignition off.
Disconnect the ECM harness connectors.
Measure the resistance between ground and the (K853) Crankshaft Position Sensor 5 Volt Supply circuit.
Measure the resistance between ground and the (K854) Boost Pressure Sensor 5 Volt Supply circuit.
Measure the resistance between ground and the (K854) Accelerator Pedal Position Sensor No. 2 5 Volt Supply circuit.
Measure the resistance between ground and the (F855) Mass Airflow Sensor 5 Volt Supply circuit.
Is the resistance above 1000 ohms for each circuit?
Yes
- Go To7
No
- Repair the 5-Volt Supply circuit that measured below 1000 ohms for a short to ground.
- Perform the ECM VERIFICATION TEST. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
7. ENGINE CONTROL MODULE (ECM)
Turn the ignition off.
Inspect the (K853) Crankshaft Position Sensor 5 Volt Supply circuit between the Crankshaft Position Sensor and the ECM.
Inspect the (K854) Boost Pressure Sensor 5 Volt Supply circuit between the Intake Air Temperature/Boost Pressure Sensor and the ECM.
Inspect the (K854) Accelerator Pedal Position Sensor No. 2 5 Volt Supply circuit between the Accelerator Pedal Position Sensor and the ECM.
Inspect the (F855) Mass Airflow Sensor 5 Volt Supply circuit between the Mass Airflow Sensor and the ECM.
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals.
Refer to any Technical Service Bulletins that may apply.
Were any problems found?
Yes
- Repair as necessary.
- Perform the ECM VERIFICATION TEST. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)
No
- Replace and program the Engine Control Module in accordance with the Service Information.
- Perform the ECM VERIFICATION TEST. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING)