P152F
P152F- ENGINE HOOD SWITCH 1 / ENGINE HOOD SWITCH 2 CORRELATION
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
Theory of Operation
Hybrid Electric Vehicles (HEV) utilize hood switches to prevent Autostart and Autostop when the hood is open. This is similar to conventional vehicles which use a single hood switch to prevent remote start when the hood is open. Hood switch 1 communicates via CAN message to NGC from the Front Control Module (FCM). Hood switch 2, mounted on the passenger side fender, is a direct input to the Powertrain Control Module. Readings of hood switch 1 and hood switch 2 are checked against the calibration thresholds to determine the switch state. There are four possible states: Hood Closed, Hood Open (Ajar), Open Circuit and Indeterminate. The Hood Switch Correlation Rationality checks to see if both hood switches are reporting the same hood state. The rationality will check the state of each sensor for one of the four states listed above. If the sensors are both reporting the same state, a message will be sent to the Hybrid Control Processor (HCP) with the determined state. If the rationality can not detect matching states from both hood switch sensors the Diagnostic Trouble Code (DTC) will set
- When Monitored:
Continuously
- Set Condition:
If the rationality can not detect matching states from both hood switch sensors.
WARNING: On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury
Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure
1. TEST FOR INTERMITTENT CONDITION
NOTE: If another hood sensor DTC is set along with this code, diagnose that hood sensor DTC first.
NOTE: Inspect the hood switch retainer rings, hood ajar switches make sure the terminals are free from corrosion and damage.
NOTE: Inspect the hood for damage or misalignment repair as necessary.
NOTE: Open the hood and ensure the Hood Ajar Switch is connected before proceeding
1. With the scan tool, record and erase DTCs.
2. Close the hood.
3. Cycle the ignition from on to off.
4. Turn the ignition on.
5. Open then close the hood.
6. With the scan tool, read DTCs.
Does the scan tool display P152F-ENGINE HOOD SWITCH 2 / ENGINE HOOD SWITCH 1 CORRELATION?
Yes
- Go To 2
No
- The conditions that caused this code to set are not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
2. HOOD AJAR SWITCH INSTALLED, DAMAGED, OR OUT OF CALIBRATION
Inspect the retainer ring, hood ajar switch, and hood for:
- Hood misalignment
- Hood slam overtravel - due to missing rubber cap on the hood stop
- Hood switch striker mispositioned
- Accidental full depression
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 3
3. HOOD AJAR SWITCH 2 OPEN
1. Disconnect the Hood Ajar Switch 2 harness connector.
2. Measure the resistance between the two terminals of the switch.
3. Depress the plunger of the hood ajar switch while taking the measurement.
Is the resistance approximately 1k Ohms?
Yes
- Go To 4
No
- Replace the Hood Ajar Switch 2.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
4. (Z990) GROUND CIRCUIT OPEN
1. Using a 12-volt test light connected to 12-volts, check the (Z990) Ground circuit.
Does the test light illuminate?
Yes
- Go To 5
No
- Repair the (Z990) Ground circuit for an open.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
5. (G97) HOOD AJAR SWITCH 2 SENSE CIRCUIT SHORT TO VOLTAGE
1. Disconnect the C4 PCM harness connector.
2. Turn the ignition on.
3. Measure the voltage between the (G97) Hood Ajar Switch 2 Sense circuit and ground.
Is there any voltage present?
Yes
- Repair the short voltage in the (G97) Hood Ajar Switch 2 Sense circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
No
- Go To 6
6. (G97) HOOD AJAR SWITCH 2 SENSE CIRCUIT OPEN
1. Turn the ignition off.
CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install PCM Pinout Box 8815 to perform diagnosis.
2. Measure the resistance of the (G97) Hood Ajar Switch 2 Sense circuit between the appropriate terminal of the PCM Pinout Box 8815 and the Hood Ajar Switch harness connector.
Is the resistance below 2.0 Ohms?
Yes
Go To 7
No
- Repair the open in the (G97) Hood Ajar Switch 2 Sense circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Powertrain Verification Test.
7. HOOD AJAR SWITCH 1 OPEN
1. Disconnect the Hood Ajar Switch 1 harness connector.
2. Measure the resistance between the two terminals of the switch 1.
3. Depress the plunger of the hood ajar switch while taking the measurement.
Is the resistance approximately 1k Ohms?
Yes
- Go To 8
No
- Replace the Hood Ajar Switch 1.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
8. (Z926) GROUND CIRCUIT OPEN
1. Using a 12-volt test light connected to 12-volts, check the (Z926) Ground circuit.
Does the test light illuminate?
Yes
- Go To 9
No
- Repair the open in the (Z926) Ground circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
9. (G70) HOOD AJAR SWITCH 1 SENSE CIRCUIT SHORT TO VOLTAGE
1. Disconnect the FCM (PDC) harness connector.
2. Turn the ignition on.
3. Measure the voltage between the (G70) Hood Ajar Switch 1 Sense circuit and ground.
Is there any voltage present?
Yes
- Repair the short to voltage in the (G70) Hood Ajar Switch 1 Sense circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Go To 10
10. (G70) HOOD AJAR SWITCH 1 SENSE CIRCUIT OPEN
1. Turn the ignition off.
2. Measure the resistance of the (G70) Hood Ajar Switch 1 Sense circuit between the FCM (PDC) harness connector and the Hood Ajar Switch harness connector.
Is the resistance below 2.0 Ohms?
Yes
- Replace the FCM.
- Perform the BODY VERIFICATION TEST. Body Verification Test.
No
- Repair the open (G70) Hood Ajar Switch 1 Sense circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.