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 P0641

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. Did the DTC fail this ignition?	-	Go to Step 3	Go to Diagnostic Aids
3	Turn OFF the ignition. Disconnect exhaust gas recirculation (EGR) valve. Turn ON the ignition, with the engine OFF. Command the EGR valve to 100 percent with a scan tool. Measure the voltage from the 5-volt reference circuit of the EGR valve 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 5	Go to Step 4
4	Is the voltage more than the specified value?	5.2 V	Go to Step 8	Go to Step 6
5	Connect the EGR valve. Disconnect the manifold absolute pressure (MAP) sensor. Command the EGR valve to 100 percent with a scan tool. Measure the voltage from the 5-volt reference circuit of the MAP 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 10
6	Monitor the DMM while disconnecting all other devices connected to the 5-volt reference circuit, one at a time. Refer to Engine Controls Component Views . If the voltage changes when one of the devices is disconnected, replace the component. Refer to the appropriate replacement procedure below: The MAP sensor - Refer to Engine Controls Component Views . The throttle position (TP) sensor - Refer to Throttle Position (TP) Sensor Replacement . Was a component replaced?	-	Go to Step 12	Go to Step 7
7	Test the 5-volt reference circuits for a short to ground or any sensor low reference circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 11
8	Test all the 5-volt reference circuits and the MAP 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 12	Go to Step 9
9	Test for a short between the EGR 5-volt reference circuit and the EGR solenoid control high circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition?	-	Go to Step 12	Go to Step 11
10	Replace the EGR valve. Refer to Exhaust Gas Recirculation (EGR) Valve Replacement . Did you complete the replacement?	-	Go to Step 12	-
11	Replace the powertrain control module (PCM). Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement?	-	Go to Step 12	-
12	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 13
13	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