Diagnostic Instructions
| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
| • | Diagnostic Procedure Instructions provide an overview of each diagnostic category. |
DTC Descriptors
| • | DTC P0651 5-volt Reference 2 Circuit is Open |
| • | DTC P0652 5-volt Reference 2 Circuit Low Voltage |
| • | DTC P0653 5-volt Reference 2 Circuit High Voltage |
Circuit Description
The control module has 3 internal 5-volt reference busses called 5-volt reference 1, 5-volt reference 2 and 5-volt reference 3. Each reference bus provides 5-volt reference circuits for more than one sensor. Therefore, a fault condition on one 5-volt reference circuit will affect other 5-volt reference circuits connected to that reference bus. The control module monitors the voltage on the 5-volt reference busses.
The 5-volt reference 2 bus provides 5 volts to the following sensors:
| • | Intake Camshaft Position (CMP) Sensor Bank 1 |
| • | Exhaust Camshaft Position (CMP) Sensor Bank 1 |
| • | Intake Camshaft Position (CMP) Sensor Bank 2 |
| • | Exhaust Camshaft Position (CMP) Sensor Bank 2 |
Conditions for Running the DTC
| • | Turn the ignition switch ON |
| • | The engine control module (ECM) power relay is turned ON |
| • | P0651, P0652 or P0653 continuously run once the above condition is present for 3 seconds. |
Conditions for Setting the DTC
The control module detects for an open, a short to ground or a short to the voltage on the 5-volt reference circuit 2.
Action Taken When the DTC Sets
| • | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails. |
| • | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records. |
Conditions for Clearing the MIL/DTC
| • | The control module turns OFF the malfunction indicator lamp (MIL) after 3 consecutive ignition cycles that the diagnostic runs and does not fail. |
| • | A current DTC, last test failed, clears when the diagnostic runs and passes. |
| • | A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic. |
Diagnostic Aids
| • | Use the J 35616-A/BT-8637 Connector Test Adapter Kit for any test that requires probing the ECM harness connector or a component harness connector. |
| • | The lower connector of the ECM is connector C1 and the upper connector of the ECM is connector C2. Refer to Engine Controls Component Views . |
| • | For an intermittent condition, refer to Intermittent Conditions . |
Step | Action | Value | Yes | No |
|---|---|---|---|---|
Schematic Reference: Engine Controls Schematics Connector End View Reference: Engine Control Module Connector End Views or Engine Controls Connector End Views | ||||
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | |
2 |
Does the DTC fail this ignition? | -- | Go to Step 3 | Go to Diagnostic Aids |
3 |
Is the voltage within the specified value? | 4.8-5.2 V | Go to Step 10 | Go to Step 4 |
4 | Is the voltage more than the specified value? | 5.2 V | Go to Step 5 | Go to Step 6 |
5 | Test for a short to voltage on the 5-volt reference circuits of all the sensors connected to the 5-volt reference voltage 2 bus. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8 |
6 | Is the voltage less than the specified value? | 4.8 V | Go to Step 7 | -- |
7 | Test for a short to ground on the 5-volt reference circuits of all the sensors connected to the 5-volt reference voltage 2 bus. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 8 |
8 |
When a sensor is disconnected, if the voltage returns to the specified value. | 4.8-5.2 V | Go to Step 9 | Go to Step 13 |
9 | Replace the sensor. Refer to appropriate sensor replacement . Did you complete the replacement? | -- | Go to Step 10 | -- |
10 |
Is the voltage within the specified range? | 4.8-5.2 V | Go to Step 14 | Go to Step 11 |
11 | Test the signal circuit of the intake camshaft position (CMP) sensor bank 1 for a short to voltage, or a mulfunction of the intake camshaft position (CMP) sensor bank 1. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 12 |
12 | Replace the intake camshaft position (CMP) sensor bank 1. Refer to Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake . Did you complete the replacement? | -- | Go to Step 14 | -- |
13 | Replace the ECM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | -- |
14 |
Does the DTC fail this ignition? | -- | Go to Step 2 | Go to Step 15 |
15 | Observe the Capture Info with a scan tool. Are there any DTCs that have not been diagnosed? | -- | System OK | |
