Diagnostic Aids

If any sensor using a 5-volt bias voltage, such as the intake air temperature (IAT) sensor or fuel sensor, is shorted to voltage, DTC P0651 may set in addition to DTC P0641.
For an intermittent condition, refer to Intermittent Conditions .

DTC P0651

Step	Action	Values	Yes	No
Schematic Reference: Instrument Cluster Schematics in Instrument Panel, Gages, and Console or Engine Controls Schematics Connector End View Reference: Instrument Panel, Gages, and Console Component Views , and Instrument Panel, Gages, and Console Connector End Views in Instrument Panel, Gages, and Console or Engine Controls Connector End Views , Powertrain Control Module (PCM) Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	-	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Observe the Freeze Frame/Failure Records for this DTC. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Does the DTC fail this ignition cycle?	-	Go to Step 3	Go to Diagnostic Aids
3	Turn OFF the ignition. Disconnect the air conditioning (A/C) pressure sensor. Turn ON the ignition, with the engine OFF. Measure the voltage from the 5-volt reference circuit of the A/C pressure sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems. Is the voltage within the specified range?	4.8-5.2 V	Go to Step 4	Go to Step 5
4	Connect the A/C pressure sensor. Disconnect the fuel tank pressure (FTP) sensor. Measure the voltage from the 5-volt reference circuit of the FTP sensor to a good ground with a DMM. Refer to Circuit Testing in Wiring Systems. Is the voltage within the specified range?	4.8-5.2 V	Go to Intermittent Conditions	Go to Step 12
5	Is the voltage measured in the previous step more than the specified value?	5.2 V	Go to Step 8	Go to Step 6
6	Monitor the DMM while disconnecting the FTP sensor. Does the voltage return to within the specified range when the FTP sensor is disconnected?	4.8-5.2 V	Go to Step 11	Go to Step 7
7	Turn OFF the ignition. Disconnect the powertrain control module (PCM). Test the 5-volt reference circuit for a short to ground or any sensor low reference circuit. Refer to Circuit Testing andWiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 14	Go to Step 13
8	Monitor the DMM while disconnecting the FTP sensor. Does the voltage return to within the specified range when the FTP sensor is disconnected?	4.8-5.2 V	Go to Step 10	Go to Step 9
9	Test all 5-volt reference circuits for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 14	Go to Step 13
10	Test the FTP sensor signal circuit for a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 14	Go to Step 13
11	Replace the FTP sensor. Refer to Fuel Tank Pressure Sensor Replacement . Did you complete the replacement?	-	Go to Step 14	-
12	Replace the A/C pressure sensor. Refer to Air Conditioning (A/C) Refrigerant Pressure Sensor Replacement in Heating, Ventilation and Air Conditioning. Did you complete the replacement?	-	Go to Step 14	-
13	Replace the PCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 14	-
14	Clear the DTCs with a scan tool. Turn OFF the ignition for 30 seconds. Start the engine. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records. Did 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?	-	Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information	System OK