Tech Tip: GM Instrument Panel Cluster (IPC) Relearn – UnderhoodService

Tech Tip: GM Instrument Panel Cluster (IPC) Relearn

You may experience a problem where a GM vehicle will not start after a replacement IPC has been installed. In this tech tip, you will learn the procedure to enable the new IPC and the ECC to communicate.

You may experience a problem where a GM vehicle will not start after a replacement Instrument Panel Cluster (IPC) has been installed.

Follow the security system (Passlock) Auto Learn procedure outlined below to enable the replacement IPC and the ECC to communicate and learn a new password.

1. Before replacing the ECC, document all existing DTCs prior to the repair.

2. Place the ignition key in the On position.

3. Using a suitable scan tool, clear all security system (Passlock) and powertrain DTCs.

4. Rotate the ignition key to the Crank position (attempt to start the vehicle). The engine will attempt to start and stall. Leave the key in the On position.

5. Wait 10 minutes. Observe the security light. It will flash for a few seconds and remain on for 10 minutes.

6. Turn the ignition key to the Off position after the Security light goes out. Wait for at least 30 seconds.

7. Repeat steps 4-6 two more times. A new password is now ready to be communicated to the security system (Passlock) sensor, IPC and ECC with the next ignition cycle (start attempt).

8. If the engine starts, the Password Auto Learn procedure is complete. If the engine fails to start, perform the relearn procedure again.

9. Check for any DTCs. Repair as necessary and clear if present.

Refer to the vehicle’s service manual for detailed relearn procedures specific to your application.

Visit www.cardone.com for more details on Flash.

You May Also Like

Alternator Testing For No Charge Conditions

Many alternator problems turn out to be nothing more than a bad connection at the alternator or a bad wiring harness.

If only battery voltage is present at the battery on a running engine, does this mean the alternator is “bad?” No, it does not. It only means that the alternator is not charging, but does not reveal why. Therefore, it does not point to a faulty alternator. All too often, the alternator is condemned by technicians due to this test alone. The cause could instead be a module that distributes the power to the vehicle and regulates the alternator.

Understanding Coolants

All-season coolant used inorganic acid technology and worked great for almost 30 years.

Ignition System Do’s and Don’ts

Why do ignition systems give technicians problems when diagnosing ignition-related misfires? The answer is that some technicians use tests that might give inconclusive results or do damage to the coil or drivers inside a module.

Tools To Service Serpentine Belts

Servicing the serpentine belt on some vehicles is a tough task.

Battery Charging and Diagnostics

Here are six tips to use when diagnosing a vehicle with a dead battery. 

Other Posts

Hybrid Vehicle Fluid Maintenance

There are opportunities your shop can’t pass up just because the car or SUV has a hybrid badge on the back.

Using a Scope

Ignition coil and plug diagnostics.

Scope-diagnostics
Repairing Wiring Harnesses

A guide to probing and poking.

Diagnostic Procedures For Stop/Start Systems

Stop/start technology is more than just a switch wired to the brake pedal and starter.