• | 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 provides an overview of each diagnostic category. |
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
---|---|---|---|---|---|
APP Sensor 2 - 5-Volt Reference | P0652 | P2138 | P2127 | P0653 | -- |
A/C Pressure Sensor - 5-Volt Reference | P0652 | P0653 | -- | ||
Oil Pressure Sensor - 5-Volt Reference | P0652, P0522 | P0522 | P0522 | P0653, P0522 | -- |
Fuel Rail Pressure Sensor - 5-Volt Reference | P0652 | P0087, P0192 | P0193 | P0653 | -- |
The engine control module (ECM) supplies 5 volts to components through 5-volt reference circuits. These 5-volt reference circuits are independent of each other outside the ECM, but are bussed together in three reference groups inside the ECM. Therefore, a circuit condition on one sensor 5-volt reference circuit may affect multiple components. The ECM monitors voltage on the 5-volt reference circuits.
• | The ignition is ON. |
• | Diagnostics run continuously. |
• | The ECM detects the 5-volt reference 2 circuit voltage is less than 4.7 volts. |
• | The above condition is present for 2 seconds. |
• | The ECM detects the 5-volt reference 2 circuit voltage is more than 5.2 volts. |
• | The above condition is present for 2 seconds. |
• | 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 Freeze Frame/Failure Records. |
• | 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. |
• | Clear the MIL and the DTC with a scan tool. |
⇒ | If the voltage measures 4.7-5.2 volts, replace the APP sensor . |
⇒ | If voltage changes when one of the above components are disconnected, replace the component. Refer to the appropriate replacement procedure. |
⇒ | If no problem was found in the 5-volt reference 2 circuit , replace the ECM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for ECM replacement, setup, and programming. |