AtWhatMileage
Electrical · 5 owner reports

Control module (ECM/PCM/BCM) failure on the 2004 GMC Envoy

Only 4 reports for this mode came with an odometer reading, which is too few for percentiles to mean anything. The page is here because someone linked to it; treat the figures as anecdotes, and see the full report for this year instead.

Reports of this failure 5
With an odometer reading 4
Reports per 1,000 built 0.2 per 1,000
Filed below 36,000 miles 25%
Mention a crash, fire or injury 0
Typical repair $700–$3,000
What it means when it happens High
Rank among this year's problems 26th

When control module (ecm/pcm/bcm) failure gets reported

There are 5 reports of control module (ECM/PCM/BCM) failure on the 2004 GMC Envoy, 4 with a mileage attached. That is too few to place the failure on the odometer with any confidence.

A part like this is normally expected to survive 92,000 miles. It is the 26th most-reported problem on this model year.

The whole distribution

Percentiles of the 4 odometer readings owners gave.
10th25thMedian 75th90th
— — 78,000 miles — —

Read the 10th percentile as “one report in ten arrived this early”. Exact figures are shown in this table because it is the table of record; everywhere else on the site they are rounded to the precision the sample can carry.

What a percentile can and cannot tell you here

These five numbers describe the readings owners gave, in order. The median is the middle one: half the reports arrived below it. The 10th and 90th are the edges of the bulk of the distribution, and the distance between them is the part worth reading. A tight spread — say 70,000 to 95,000 miles — points at something that wears out on a schedule, and the schedule is knowable. A wide one, 20,000 to 190,000, points at a fault that hits some cars and never troubles others, which means the mileage on the listing in front of you tells you very little about your odds.

What these figures are not is a survival curve. Every reading here comes from a car whose owner filed a complaint, so the sample contains only failures: it cannot say what share of the fleet made it past 150,000 miles untouched, because those owners had nothing to report. Nor is the mileage the moment of failure — it is the odometer reading as recalled at the time of filing, which may be weeks later and is sometimes rounded to the nearest ten thousand by the person typing it.

Percentiles are shown at all only once 8 readings exist for the vehicle and mode. Below that the middle of a handful of numbers is noise wearing a decimal point, so the figures are withheld rather than dressed up.

What happens, and what it costs

Putting it right typically runs $700–$3,000 at an independent US shop. That range is an editorial estimate held in this site's failure-mode catalogue, not a figure from NHTSA, and it is a repair cost rather than a diagnosis cost.

The same failure on other years

The same failure is reported on 6 model years of this car. It shows up earliest on the 2002, at a median of 35,000 miles, and latest on the 2007 at 160,000 miles.

By volume the 2002 carries the most reports, with 20; the 2004 has 5. A mode that appears across most years of a model is usually a design choice rather than a bad batch.

If one year stands out to the left, that is the year to avoid; if the whole line sits at a similar mileage, this is wear rather than a defect in one production run.

Median
  1. 1998 GMC Envoy control module (ecm/pcm/bcm) failure
    no odometer readings given
    —
  2. 2001 GMC Envoy control module (ecm/pcm/bcm) failure 46k
  3. 2002 GMC Envoy control module (ecm/pcm/bcm) failure 35k
  4. 2003 GMC Envoy control module (ecm/pcm/bcm) failure 78k
  5. 2004 (this one) 78k
  6. 2005 GMC Envoy control module (ecm/pcm/bcm) failure 56k
  7. 2006 GMC Envoy control module (ecm/pcm/bcm) failure 137k
  8. 2007 GMC Envoy control module (ecm/pcm/bcm) failure 160k

Tick median reported mileage Solid middle half of reports Faint 10th to 90th percentile Colour how bad the failure is when it happens

What owners wrote

Verbatim from NHTSA complaint narratives, trimmed for length. The mileage is the one the owner gave.

I own a 2004 gmc envoy,just purchased in january.I feel very unsafe driving it, for when I try to accelerate it just loses power feels like its gonna die out.the rpms are going up and down when I try to accelerate.it,s gonna end up causing me to get in a wreck.I brought it to dealerhip last thurs,they updated the software in PCM. I had to put it back in shop today for doing the same thing I feel as if they arent gonna find whats wrong b/c the check engine light isnt on and it doesn,t act up all the time.I really feel this is of major concern b/c I,m seeing a lot of complaints posted with this same problem in envoys and trailblazers.I think its time time for a recall don,t ya,ll?

33,000 miles NHTSA complaint 544916 filed 2005-07-19

Stopped at street like, light went green started to move forward and car goes dead. No lights on dash, nothing showing, just stops abruptly. After a few moments tried restarting car and it came back on with check engine light. P0606 PCM failure code displayed. Could have been rear ended by semi truck behind me or killed if I was trying to turn left at intersection. *tr

78,000 miles NHTSA complaint 1080442 filed 2014-06-27

Stopped at street like, light went green started to move forward and car goes dead. No lights on dash, nothing showing, just stops abruptly. After a few moments tried restarting car and it came back on with check engine light. P0606 PCM failure code displayed. Could have been rear ended by semi truck behind me or killed if I was trying to turn left at intersection. *tr

78,000 miles NHTSA complaint 1080443 filed 2014-06-27

Also reported on the 2004 GMC Envoy

Instrument cluster or gauge failure

78 reports median 64k

Other electrical problem

52 reports median 68k

Fuel tank, filler or EVAP failure

26 reports median 107k

Fuel gauge or level sensor failure

23 reports median 51k

Other body or interior problem

22 reports median 115k

Other lighting problem

21 reports median 86k

How far this goes

This page is kept out of search results because 5 reports is not enough to publish percentiles from. It stays reachable because somebody looking at this exact car would rather see the reports than be told there are none.

Complaints are voluntary, so 5 is a floor and not a count of affected cars. Mileages are typed in by owners and cluster on round numbers. And the mode itself is assigned by software reading the complaint text, which is reliable in bulk and fallible one report at a time.

Questions this page answers

At what mileage does control module (ecm/pcm/bcm) failure happen on the 2004 GMC Envoy?

Across 4 owner reports that included an odometer reading, half were filed by 80,000 miles. A quarter were filed before — and a quarter after —. These are the mileages owners reported when they complained, not a prediction for any individual car.

How common is control module (ecm/pcm/bcm) failure on the 2004 GMC Envoy?

5 reports have been filed with NHTSA, about 0.2 per 1,000 vehicles. Complaints are voluntary, so this is a floor rather than a count of affected cars.

What this is and is not. These are the mileages at which owners chose to complain to a federal agency, which is not the same as the mileage at which the part fails on every car. It skews toward failures that happened outside warranty, cost real money, or frightened someone. It is still the only public dataset that carries failure mileage at all, and the shape of a few hundred readings is informative even when a single one is not. Methodology · JSON · this failure on other cars

Source Owner complaints and recall records published by the US National Highway Traffic Safety Administration, model years 1996–2027 Figures rebuilt Published by AtWhatMileage How every figure is computed