P1397 – OBD-II DTC

OBD-II DTC P1397 – Glow Plug Circuit High Input (Bank #1)

DTC P1397 meaning

DTC P1397 refers to a diagnostic trouble code indicating a high input signal from the glow plug circuit on Bank #1 of a diesel engine. This code is triggered when the Engine Control Module (ECM) detects that the voltage or resistance in the glow plug circuit exceeds the expected range, suggesting a potential issue with the glow plugs or their associated wiring.

DTC P1397 symptoms

Common symptoms associated with DTC P1397 may include:

• Difficulty starting the engine, especially in cold conditions
• Increased engine cranking time
• Rough idling or misfiring
• Decreased fuel efficiency
• Check Engine Light (CEL) illuminated

DTC P1397 causes

Several factors can lead to the triggering of DTC P1397, including:

• Faulty glow plugs
• Damaged or corroded wiring in the glow plug circuit
• Defective glow plug relay
• Issues with the Engine Control Module (ECM)
• Short circuits or open circuits in the glow plug circuit

DTC P1397 seriousness

The seriousness of DTC P1397 can vary based on the underlying issue. While it may not cause immediate engine damage, it can lead to:

• Starting difficulties, particularly in cold weather
• Increased emissions due to incomplete combustion
• Potential long-term damage to the engine if not addressed

It is advisable to diagnose and repair the issue promptly to maintain optimal engine performance.

How to diagnose DTC P1397

To diagnose DTC P1397, follow these steps:

1. Use an OBD-II scanner to confirm the presence of the P1397 code.
2. Inspect the glow plugs for physical damage or wear.
3. Check the wiring and connectors for corrosion, breaks, or loose connections.
4. Test the glow plug relay for proper operation.
5. Measure the voltage and resistance in the glow plug circuit to ensure they are within specifications.
6. Examine the ECM for any faults or updates that may be necessary.

How to fix DTC P1397 step-by-step instructions

To fix DTC P1397, follow these step-by-step instructions:

1. Disconnect the battery to ensure safety while working on the electrical system.
2. Inspect and replace any faulty glow plugs as needed.
3. Repair or replace damaged wiring and connectors in the glow plug circuit.
4. Test and replace the glow plug relay if it is found to be defective.
5. Reconnect the battery and clear the DTC using an OBD-II scanner.
6. Start the engine and monitor for any reoccurrence of the P1397 code.

How to erase DTC P1397

To erase DTC P1397, follow these steps:

1. Connect an OBD-II scanner to the vehicle’s diagnostic port.
2. Turn on the ignition without starting the engine.
3. Navigate to the “Erase Codes” or “Clear DTCs” option on the scanner.
4. Confirm the action to clear the trouble codes.
5. Disconnect the scanner and start the engine to ensure the code does not return.

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