P257E
DTC P257D-P257F
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 provides an overview of each diagnostic category.
DTC Descriptors
DTC P257D
- Engine Hood Switch Performance
DTC P257E
- Engine Hood Switch Circuit Low Voltage
DTC P257F
- Engine Hood Switch Circuit High Voltage
Diagnostic Fault Information
Circuit/System Description
The starter/generator control module applies B+ to the hood ajar signal 2 circuit and monitors the voltage to determine the position of the hood. The hood ajar switch contains a multiplexed resistor. This resistor will vary the voltage seen by the starter/generator control module by pulling down the applied voltage based on the position of the switch.
Conditions for Running the DTC
Propulsion system is active.
Conditions for Setting the DTC
P257D
The hood ajar switch signal 2 voltage as measured by the starter/generator control module is not within a valid voltage range.
P257E
The hybrid powertrain control module 2 detects a short to ground in the hood ajar signal input to the starter/generator control module.
P257F
The hybrid powertrain control module 2 detects a short to voltage or an open/high resistance in the hood ajar signal input to the starter/generator control module.
Action Taken When the DTC Sets
The engine will start and run whenever the vehicle ignition is on or the vehicle speed is less than 5 kph (3 mph).
Conditions for Clearing the DTC
DTCs P257D, P257E, and P257F are Type B DTCs.
Reference Information
Schematic Reference
Immobilizer Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Hood Ajar Indicator Description and Operation Description and Operation
Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
1. Ignition ON.
2. Observe the scan tool hybrid powertrain control module Hood Position parameter. With the hood open, the Hood Position parameter should be Open. With the hood closed, the Hood Position parameter should be Closed.
• If the parameter does not change
Refer to Circuit/System Testing.
• If the parameter changes
3. All OK.
Circuit/System Testing
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B55 hood ajar switch. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal C and ground.
• If 10 ohms or greater
1. Ignition OFF
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify DTC P257F is set as current
• If DTC P257F is not set as current
1. Ignition OFF, disconnect the harness connector at the K59 starter/generator control module.
2. Test for infinite resistance between the signal circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K59 starter/generator control module.
• If DTC P257F is set as current
5. Install a 5 A fused jumper wire between the signal circuit terminal A and ground. Ignition ON
6. Verify DTC P257E is set as current.
• If DTC P257E is not set as current
1. Ignition OFF, disconnect the harness connector at the K59 starter/generator control module.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If DTC P257E is set as current
7. Test or replace the B55 hood ajar switch.
Component Testing
1. Ignition OFF, disconnect the harness connector at the B55 hood ajar switch.
2. Test for 2738-3350 ohms between the signal terminal A and the signal terminal B with the hood latch in the CLOSED position.
• If not between 2738-3350 ohms
Replace the B55 hood ajar switch.
• If between 2738-3350 ohms
3. Test for 658-806 ohms between the signal terminal A and the ground terminal C with the hood latch in the CLOSED position.
• If not between 658-806 ohms
Replace the B55 hood ajar switch.
• If between 658-806 ohms
4. Test for 2080-2545 ohms between the signal terminal B and the ground terminal C with the hood latch in the CLOSED position.
• If not between 2080-2545 ohms
Replace the B55 hood ajar switch.
• If between 2080-2545 ohms
5. Test for 2738-3350 ohms between the signal terminal A and the signal terminal B with the hood latch in the OPEN position.
• If not between 2738-3350 ohms
Replace the B55 hood ajar switch.
• If between 2738-3350 ohms
6. Test for 2080-2545 ohms between the signal terminal A and the ground terminal C with the hood latch in the OPEN position.
• If not between 2080-2545 ohms
Replace the B55 hood ajar switch.
• If between 2080-2545 ohms
7. Test for 658-806 ohms between the signal terminal B and the ground terminal C with the hood latch in the OPEN position.
• If not between 658-806 ohms
Replace the B55 hood ajar switch.
• If between 658-806 ohms
8. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
* Hood Primary and Secondary Latch Replacement Service and Repair
* Control Module References for starter/generator control module or body control module replacement, programming and setup