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2002 Chevrolet Duramax Diesel DTC P0234 and P0380 Troubleshooting Guide

Model: Chevrolet Duramax Fault Code: P0234 Posted: 2008-04-25 20:03

I own a 2002 Chevrolet 2500HD with the 6.6L Duramax diesel engine, currently at 87,000 miles. I recently installed a Hypertech Power Programmer III to enhance performance. When the Service Engine Soon light illuminated, I noticed intermittent hesitation and engine skipping. To diagnose the issue, I disconnected the programmer and reset the truck to factory settings. After resetting, the onboard diagnostic system returned two trouble codes: P0234 and P0380. Can anyone provide insight into what these codes mean or recommend reliable sources for interpreting diesel engine diagnostic codes? Any advice on potential fixes would be greatly appreciated.

Related fault codes
P0234P0380
Comments (7)
Anonymous 2008-04-26 09:08

P0234 indicates an engine overboost condition, which occurs when the turbocharger pressure exceeds safe limits. P0380 points to a malfunction in the glow plug or heater circuit (Circuit A).

Anonymous 2008-04-26 18:12

I believe there was a factory recall or wiring harness adjustment for certain models, specifically related to fuel injector and glow plug harnesses. These components are prone to fatigue over time, leading to intermittent faults. Regarding P0234, performance chips like the Hypertech Programmer III can sometimes trigger overboost conditions—especially if no other modifications have been made.

Anonymous 2008-04-26 19:13

Welcome back, Darkrooms!

Anonymous 2008-04-28 06:50

Yeah, glad to see you back in the forum, Darkrooms!

Anonymous 2008-04-29 15:01

I just wanted to check in on how things are going. I’ll visit occasionally, but honestly, your discussions have been well-covered—great to hear from you both.

Anonymous 2008-04-29 20:41

Agreed! It's nice to see you back, Darkrooms.

Anonymous 2008-04-30 10:58

Hey, we always benefit from more expert input—don’t be a stranger!