How To Fix P0602 0BD2 Code?

Affiliate Disclimer: ObdCore is reader supported, if you click on a link and make a purchase, We may receive commissions from purchases made via our links at no additional costs to you.

How To Fix P0602 0BD2 Code?
Table of Contents

The P0602 0BD2 code is a DTC (Diagnostic Trouble Code), and when the Powertrain Control Module (PCM) stores a P0602 0BD2 code is an indication of a programming error in one of the control modules. 

P0602 OBD2 code Meaning

P0602 OBD2 code Meaning 

The programming error could be in one of the following modules including the body control module, the anti-theft module, the transmission control module, the antilock brake control module, the traction control module, the turbo control module, the proximity alert module, the fuel injection control module, and the instrument panel control module.

OBD-II Code P0602: Symptoms, Causes & Fix

Symptoms of a P0602 OBD2 code

The symptoms of a P0602 0BD2 trouble code include:

  • Problems driving and shifting.
  • Engine stalls and rough idling.
  • Poor acceleration.
  • Drastic decrease in the vehicle’s fuel economy.
  • Harsh and erratic automatic transmission shifting.

 Causes of a P0602 OBD2 code

Some of the causes of a P0602 0BD2 trouble code include:

  • A Powertrain Control Module (PCM) programming error.
  • A blown ECM or PCM fuse. 
  • A defective driver in the ECM or PCM.
  • Faulty connectors within the CAN (Control Area Network)
  • A loose or broken wire/ground strap.
  • A defective Control Area Network (CAN) Bus. 
  • Shorted wiring within the CAN harness.
  • An ECM or PCM power supply relay. 
  • Installation of an aftermarket, high-performance PCM program.

How to diagnose a P0602 OBD2 code.

Diagnosing a P0602 0BD2 trouble code can be a challenging affair even at the hands of the most experienced and most equipped mechanic. However, there are still some diagnostic processes one can run before throwing in the towel and handing over the problem to someone else.

The diagnostic process begins with:

  • A visual inspection of the engine’s wiring connectors and harnesses.: Any connector or wiring harness that might have been burnt or damaged should either be replaced or repaired. 
  • Connect the tool scanner to the car’s diagnostic connector to retrieve the freeze frame data and any other stored codes: Make sure that before you clear any of the codes write the codes down somewhere in case it turns out to be an intermittent code. Before diagnosing and repairing any of the other codes ensure that the P0602 0BD2 trouble code is the first to be dealt with, as the other codes are likely to be false. 
  • In case the P0602 0BD2 trouble code is immediately reset make sure the battery voltage in the PCM: This is mainly because the PCM requires a specific battery voltage to function properly. In case the battery terminals are loose or corroded the amount of voltage reaching the PCM might be inadequate. Also, make sure to check the PCM’s fuses and relays for any battery voltage when the circuit is loaded, this is because there are instances that a corroded fuse might appear normal to the human eye until a load is applied and the deficiency is finally revealed.
  • Check whether the PCM has been recently replaced.: If the PCM has just been replaced, there is a chance that the P0602 0BD2 trouble code is being caused by improper programming of the PCM, or even it might have not been programmed at all. Also, note that a PCM from another vehicle can be used in your vehicle unless it has been reprogrammed specifically to meet the needs of your vehicle. Also aftermarket, high-performance programmers might not be recognized by your vehicle’s controllers, which could be the root cause of the P0602 0BD2 trouble code. 
  • Check out for incorrectly replaced or incorrectly programmed controllers: In case that’s the case you should reprogram the controllers with a factory scanner, and in case you cannot get your hands on such a scanner, most dealerships will be happy to reprogram your PCM for a nominal fee.

Common mistakes to avoid when diagnosing a P0602 OBD2 code

When diagnosing a P0602 0BD2 trouble code there are several mistakes even the most qualified mechanic is likely to make, these common mistakes include:

  • Repairing or replacing the wiring harness without first checking whether the connections are damaged or not.
  • Treating the P0602 0BD2 trouble code as if it requires the same repair method as a previous P0602 0BD2 trouble code, while its common knowledge that different P0602 0BD2 trouble codes can be caused by totally different faults. 
  • Not using the genuine replacement parts for your vehicle’s brand and make.
  • Adding new components before determining which components are not functioning as they should.
  • Not clearing other trouble codes which are likely to cause this same problem to re-occur or even some other related problems.
  • Reprogramming the vehicle’s control modules without first determining what control module is causing the P0602 0BD2 trouble code. 

How to fix a P0602 OBD2 code.

How to fix a P0602 OBD2 code.

After a thorough diagnosis a qualified technician will be able to offer you the right repair options for your P0602 0BD2 trouble code, which could entail any of the following:

  • Replacing or repairing the faulty PCM.
  • Replacing or repairing any of the faulty components in different control modules.
  • Repairing or replacing any of the damaged connectors and wiring harnesses. 
  • Make sure that all the connectors are securely connected. 

Tips to avoid a P0602 OBD2 code error.

  • If you are replacing your vehicle’s PCM with a new or used one, make sure that it is programmed specifically to match the vehicle in question.
  • Also, note that most of the aftermarket or high-performance programmers will require some time for your vehicle’s current controllers to recognize them.
  • A PCM might look like a regular metal box, but inside it is a management system that is essential to the daily operations of your car’s engine. And any vital information to the management of the engine from the factory is programmed into the PCM using Electronically Erasable Programmable Read-Only Memory (EEPROM).
  • Each vehicle is equipped with its unique settings for the engine and transmission management, which are programmed into the vehicle’s EEPROM. Which helps to manage the engine’s performance and efficiency level.
  • If the PCM detects any inconsistencies with the EEPROM then a P0602 0BD2 trouble code is stored.