Control module (ECM/PCM/BCM) failure on the 1999 Jeep Grand Cherokee
When control module (ecm/pcm/bcm) failure gets reported
Owners of the 1999 Jeep Grand Cherokee report control module (ECM/PCM/BCM) failure at a median of 95,000 miles. A quarter of the reports come in before 60,000 miles and a quarter after 110,000 miles, from 11 reports that carried an odometer reading.
A part like this is normally expected to survive 92,000 miles. It is the 25th most-reported problem on this model year.
The mileage distribution
The reported range runs from 55,000 miles at the tenth percentile to 145,000 miles at the ninetieth, a spread of 89,170 miles across the middle 80% of reports.
When the reports scatter this far, the mileage is telling you about how these cars were driven more than about the part itself.
9% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 54,000 miles | 59,100 miles | 95,000 miles | 112,144 miles | 143,170 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 25 model years of this car. It shows up earliest on the 2013, at a median of 5,000 miles, and latest on the 1998 at 160,000 miles.
By volume the 2014 carries the most reports, with 52; the 1999 has 21. 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.
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.
1999 jeep grand cherokee laredo. The airbag light comes on with left turn of vehicle. The dealer can not easily figure out what causes this. Others have had this same problem with this vehicle. I think a recall should be done to correct this.
Sporadic harsh 1-2 shift at low speeds of 15-20 MPH, usually soon after a cold start of the engine. Jeep seems to "jump" or "stall", which is especially dangerous when pulling out into traffic. "check engine" light illuminates shortly after each incident. Reprogramming the transmission computer multiple times, replacing the solonoid pack, and replacing the control module have all failed to correct the problem. Problem has occurred intermittently throughout the nearly 60,000 miles driven to date. Reported to jeep dealer at the following mileage intervals: 9,606 miles, 13,575 miles, 15,113 miles, 56,368 miles, 56,917 miles, 57,115 miles, and 58,190 miles.
The air bag light illuminated intermittently while driving. Dealer was notified. Although there was a recall concerning the clock spring dealer informed the consumer that his vehicle was not covered under the recall due to VIN. *ak *tc
Also reported on the 1999 Jeep Grand Cherokee
Premature brake pad or rotor wear
Other powertrain problem
Other brake problem
Other body or interior problem
Differential or transfer case failure
Other visibility problem
How far this goes
Complaints are voluntary, so 21 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 1999 Jeep Grand Cherokee?
Across 11 owner reports that included an odometer reading, half were filed by 95,000 miles. A quarter were filed before 60,000 miles and a quarter after 110,000 miles. 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 1999 Jeep Grand Cherokee?
21 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