2014-2016 Lexus IS & RC Gateway Module: Fixing the Battery Drain Issue
This guide details the common battery drain failure in 2014-2016 Lexus IS and RC models, caused by a faulty Serial Data Gateway Module, and explains how to replace it without dealer programming.
- A faulty Serial Data Gateway Module is a common cause of battery drain in these Lexus models, as documented in TSB L-SB-0035-16.
- Replacement is plug-and-play and does NOT require any dealer programming or special tools, making it a great DIY repair.
- To fix the issue, replace the original part (89100-30151) with an updated version like 89100-30160 or 89100-30221.
- The module is located behind the glove box and can be replaced in under two hours with basic hand tools.
Is Your Lexus Battery Dying? The Gateway Module May Be the Cause
A common and frustrating problem for owners of the 2014-2015 Lexus IS250, 2014-2015 Lexus IS350, 2016 Lexus IS200t, 2016 Lexus IS300, 2015 Lexus RC350, and 2015 Lexus RC F is a battery that dies intermittently, often overnight or after sitting for a couple of days. While a bad battery is always a possibility, a well-documented cause for this issue is a faulty Serial Data Gateway Module.
Lexus issued Technical Service Bulletin (TSB) L-SB-0035-16 specifically for this problem on 2014-2015 IS models. The TSB explains that early versions of the gateway module can fail to enter 'sleep mode' when the car is turned off. This causes it to continue drawing power, resulting in a parasitic drain that kills the battery. The fix is to replace the original module with an updated part.
Symptoms of a Failing Serial Data Gateway Module
The most reported symptom for these Lexus models is a parasitic battery drain. However, since the gateway controls all data traffic, a failure can manifest in many ways. You may experience one or more of the following issues:
- Dead Battery: The battery is repeatedly drained after the vehicle sits for a day or more.
- Widespread Electrical Gremlins: Multiple, unrelated electronic systems may malfunction at the same time.
- Instrument Cluster Issues: Gauges may stop working, fluctuate wildly, or the entire display may be dead.
- Warning Lights: Multiple warning lights may illuminate on the dashboard for systems like ABS, airbags, or traction control due to communication loss.
- Features Stop Working: Power windows, door locks, radio, navigation, or climate controls may become inoperative.
- No-Start or Start-and-Stall: The vehicle may refuse to crank or start and then immediately shut off.
- Communication DTCs: A scan tool will likely show multiple 'U' codes, which indicate a loss of communication between modules (e.g., U0155, U0140, U0448).
Pro Tip: Before replacing the module, it's wise to have your battery and alternator professionally tested to rule them out. If the battery tests good, a parasitic draw test can confirm if a component is staying 'awake' after the car is off. The TSB for this issue outlines a specific procedure for measuring this draw.
Known Issues, TSBs, and Recalls
Technical Service Bulletin L-SB-0035-16
This is the key document for the battery drain issue. It applies to 2014-2015 Lexus IS250 and IS350 models produced before certain VINs, particularly those equipped with Blind Spot Monitor or Clearance Warning Sonar. It identifies the original gateway module (part number 89100-30151) as the cause and instructs technicians to replace it with the updated part (89100-30160). While the TSB doesn't explicitly list the 2016 IS models or the RC models, they share the same platform and parts, and the issue is widely understood to affect them as well.
There are no known safety recalls for this specific part on these vehicles.
Replacement and Programming
Location
The Serial Data Gateway Module is located behind the glove box on the passenger side of the dashboard. To access it, the glove box assembly must be removed. This involves removing several plastic trim panels and a series of Phillips screws and 10mm bolts.
Does This Module Need to Be Programmed?
No. For the 2014-2016 Lexus IS and RC models covered here, the Serial Data Gateway Module is a plug-and-play part. You do not need a dealer or special tools to program, flash, or initialize the module. After installing the replacement, you should clear any stored Diagnostic Trouble Codes (DTCs) with a standard OBD-II scanner, but no further programming is required. This makes it an excellent DIY-friendly repair.
Warning: While it is recommended to disconnect the negative battery terminal before replacing any electronic component, be aware that some sellers of used modules may claim programming is needed. For these specific Lexus models, extensive owner feedback confirms it is not necessary.
Buying a Used Serial Data Gateway Module
A used OEM module is a smart and cost-effective solution for this common problem. Since this is a purely electronic part with no moving components, a unit from a low-mileage, collision-damaged vehicle is just as reliable as a new one, especially if you get the updated part number.
- Verify the Part Number: The most important step. For a permanent fix, you want the updated part number. The original, faulty part is 89100-30151. The first updated, corrected part is 89100-30160. This part has since been superseded by 89100-30221. Any of these updated numbers will work. Avoid buying another `89100-30151` unless you want to risk the problem returning.
- Compatibility Check for RC Models: For the 2015 Lexus RC350, it is critical to match the part number exactly. Interchange data shows that part number 89100-30160 is correct, confirming the need for a precise match for this model.
- Inspect the Connectors: When you receive the part, check that the pins in the electrical connectors are straight and free of any corrosion or damage.
- Source is Key: Purchase from a reputable recycler that offers a warranty. This protects you in the rare case that you receive a defective unit.
Cost of Replacement
Replacing the Serial Data Gateway Module is relatively inexpensive, especially if you do it yourself.
| Part/Service | Estimated Cost |
|---|---|
| New OEM Module | $135 - $185 |
| Used OEM Module | $25 - $75 |
| Shop Labor | $150 - $250 |
Labor cost is estimated based on the 1.2-hour book time for this job at a typical shop rate of $125-$210/hour.
Frequently Asked Questions (FAQ)
Which part number should I buy to fix the battery drain?
You should buy the updated part number, which is 89100-30160 or the even newer superseding part number 89100-30221. Avoid the original part number, 89100-30151, as it is the one known to cause the issue.
Can I replace the gateway module myself?
Yes, this is a very feasible DIY job for someone with basic tools. The module is located behind the glove box. The replacement involves removing trim panels and screws to access the part, which is then simple to unplug and swap. Since no programming is required, it's a straightforward remove-and-replace job.
Will a used gateway module work?
Yes, a used module is an excellent option. Just ensure you are buying the updated part number (89100-30160 or newer) from a reputable seller with a warranty.
My car is a 2016 IS300, does the TSB apply to me?
Technically, TSB L-SB-0035-16 only lists the 2014-2015 IS250/350. However, the 2016 IS200t and IS300 are built on the identical platform and use the same family of parts. The battery drain issue is known to affect these models as well. The solution—replacing the gateway module with the updated part number—is the same.
Technical Specifications
OEM Part Numbers: 89100-30151 89100-30160 89100-30221
Location: Behind glove box, passenger side dashboard. Function: Central network router for CAN, LIN, and other vehicle data buses.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- Lexus IS350:
- Lexus IS250:
- Lexus IS300:
- Lexus RC350:
- Lexus RC F:
- Lexus IS200t:
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- Is Your Lexus Battery Dying? The Gateway Module May Be the Cause
- Symptoms of a Failing Serial Data Gateway Module
- Known Issues, TSBs, and Recalls
- Technical Service Bulletin L-SB-0035-16
- Replacement and Programming
- Location
- Does This Module Need to Be Programmed?
- Buying a Used Serial Data Gateway Module
- Cost of Replacement
- Frequently Asked Questions (FAQ)
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