P0602 Control Module Programming Error

Description and meaning of DTC p0602

This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles (Dodge Ram Cummins, Chevy GMC Duramax, Isuzu, Volvo, Vauxhall, VW, etc. ). Although generic, the specific repair steps may vary depending on make/model.

p0602 diagnostic trouble code symptoms

A stored code P0602 should be categorized as severe because conditions that caused it to be stored may affect engine management in a major way. Symptoms of a P0602 code may include: No start conditionMultiple drivability issuesHarsh or erratic automatic transmission shiftingDiminished fuel efficiencyThe engine may stall or idle roughly

DTC p0602 - possible causes

Possible causes for this code include: PCM programming errorNew or incorrect PCMAftermarket (high-performance) PCM program installedBlown ECM/PCM fuseBad ECM/PCM power supply relayA defective ECM/PCMOpen or shorted wiring or connectors in the CAN harnessInsecure control module ground strap or broken ground wire

How to fix OBD-II diagnostic trouble code p0602

Diagnosing a code P0602 can be challenging, even to the most experienced and well equipped technician. Nevertheless, there are a few preliminary tests that can be performed before throwing your hands in the air and passing the problem off to someone else. As usual, I would begin my diagnosis with a visual inspection of engine management wiring harnesses and connectors. Any wiring and connectors that have been damaged or burned should be repaired or replaced. Next, I would connect the scanner to the vehicle diagnostic connector and retrieve all stored codes and freeze frame data. Before clearing the codes, I would write them down just in case this proves to be an intermittent code. A code P0602 must be diagnosed and repaired before diagnosing and repairing any other stored codes, as other stored codes are likely to be false. Now clear the codes in the hope that the P0602 has been stored in error. If the P0602 is immediately reset, check for battery voltage to the PCM. The PCM requires battery voltage to function properly. If the battery terminals are corroded or loose, there may be inadequate voltage reaching the PCM. Check PCM relays and fuses for battery voltage with the circuit loaded. Corroded fuses may appear normal until a load is applied to the circuit and their deficiency is revealed. Obviously, if the PCM has been recently replaced, the likelihood that it was improperly programmed or not programmed at all is great. Also, a controller from another vehicle cannot be used unless it has been reprogrammed specifically for the vehicle in question and aftermarket (high-performance) programmers may not be recognized by other controllers (especially at first), causing a P0602 to be stored. Incorrectly programmed or replaced controllers may be reprogrammed with a factory scanner. If you cannot gain access to such a scanner, most dealerships offer PCM programming for a nominal fee. Some aftermarket PCM manufacturers offer preprogrammed controllers for certain models. Check your auto parts supplier and have the vehicle identification number, mileage, and other pertinent data available. Additional diagnostic notes:New or used, a replacement PCM will need to be programmed to match the vehicle in questionAftermarket or high-performance programmers will frequently require time for other controllers to recognize them - if they ever do

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