Ignition switch, key fob or immobilizer failure on the 2008 Jeep Grand Cherokee
When ignition switch, key fob or immobilizer failure gets reported
Owners of the 2008 Jeep Grand Cherokee report ignition switch, key fob or immobilizer failure at a median of 90,000 miles. A quarter of the reports come in before 65,000 miles and a quarter after 112,500 miles, from 72 reports that carried an odometer reading.
A part like this is normally expected to survive 85,000 miles. It is the 2nd most-reported problem on this model year.
The mileage distribution
The reported range runs from 22,500 miles at the tenth percentile to 155,000 miles at the ninetieth, a spread of 133,097 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.
11% of the dated reports were filed under 36,000 miles.
The whole distribution
| 10th | 25th | Median | 75th | 90th |
|---|---|---|---|---|
| 21,700 miles | 63,782 miles | 89,500 miles | 113,250 miles | 154,797 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 $250–$1,500 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 17 model years of this car. It shows up earliest on the 2018, at a median of 10,000 miles, and latest on the 1998 at 140,000 miles.
By volume the 2005 carries the most reports, with 141; the 2008 has 96. 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.
Sudden acceleration/ loss of brakes. Vehicle accelerated to full throttle while entering from freeway onramp. The driver took foot off accelerator and vehicles accelerator pedal continued to move downward to full throttle and would not decelerate after an attempt to "pump" the accelerator pedal to try and get the pedal to release. The automobile was then put in neutral and the engine would not slow down in" RPM's". The brakes were applied and an attempt was made to stop the vehicle and the brakes were not functioning properly with the automobile coming to a very long and slow stop white trying to maneuver the automobile to the side of the road. Once the vehicle was brought to a stop the motor was still at an extreme "RPM" level. The motor was turned off at the ignition switch and the engine finally stopped running. After sitting at the side of the road for sometime the vehicle was restarted and driven to a safe location where the driver let the vehicle sit for an hour or two and restarted for the final drive home(about five miles). The vehicle was taken to the dealers service department the next business day. The dealer ran a scan…
Sudden acceleration/ loss of brakes. Vehicle accelerated to full throttle while entering from freeway onramp. The driver took foot off accelerator and vehicles accelerator pedal continued to move downward to full throttle and would not decelerate after an attempt to "pump" the accelerator pedal to try and get the pedal to release. The automobile was then put in neutral and the engine would not slow down in" RPM's". The brakes were applied and an attempt was made to stop the vehicle and the brakes were not functioning properly with the automobile coming to a very long and slow stop white trying to maneuver the automobile to the side of the road. Once the vehicle was brought to a stop the motor was still at an extreme "RPM" level. The motor was turned off at the ignition switch and the engine finally stopped running. After sitting at the side of the road for sometime the vehicle was restarted and driven to a safe location where the driver let the vehicle sit for an hour or two and restarted for the final drive home(about five miles). The vehicle was taken to the dealers service department the next business day. The dealer ran a scan…
Sudden acceleration/ loss of brakes. Vehicle accelerated to full throttle while entering from freeway onramp. The driver took foot off accelerator and vehicles accelerator pedal continued to move downward to full throttle and would not decelerate after an attempt to "pump" the accelerator pedal to try and get the pedal to release. The automobile was then put in neutral and the engine would not slow down in" RPM's". The brakes were applied and an attempt was made to stop the vehicle and the brakes were not functioning properly with the automobile coming to a very long and slow stop white trying to maneuver the automobile to the side of the road. Once the vehicle was brought to a stop the motor was still at an extreme "RPM" level. The motor was turned off at the ignition switch and the engine finally stopped running. After sitting at the side of the road for sometime the vehicle was restarted and driven to a safe location where the driver let the vehicle sit for an hour or two and restarted for the final drive home(about five miles). The vehicle was taken to the dealers service department the next business day. The dealer ran a scan…
Also reported on the 2008 Jeep Grand Cherokee
Other electrical problem
Other engine problem
No-start or intermittent start failure
Other powertrain problem
Stalling while driving
Differential or transfer case failure
How far this goes
Complaints are voluntary, so 96 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 ignition switch, key fob or immobilizer failure happen on the 2008 Jeep Grand Cherokee?
Across 72 owner reports that included an odometer reading, half were filed by 90,000 miles. A quarter were filed before 65,000 miles and a quarter after 112,500 miles. These are the mileages owners reported when they complained, not a prediction for any individual car.
How common is ignition switch, key fob or immobilizer failure on the 2008 Jeep Grand Cherokee?
96 reports have been filed with NHTSA, about 1.6 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