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Does anyone have a diagram of the location of the TPMS RECEIVER in a C7? GM Parts | Part# 84429916
Low Tire Pressure Indicator Module #22923527
I have had an intermittent TPMS indicator on the passenger front tire for several years, wherein the indicator light with no pressure reading periodically comes on and then resets itself after a few minutes I have had the TPMS sensors replaced. The warning is now coming on more often than not. I have rotated tires, and I even have a spare set of rims/tires with their own TPMS sensors - but the indicator and pressure reading is intermittent on the passenger front, which lead me to the receiver module.
Help much appreciated, and if I am going in the wrong direction, please share.
Does anyone have a diagram of the location of the TPMS RECEIVER in a C7? GM Parts | Part# 84429916
Low Tire Pressure Indicator Module #22923527
I have had an intermittent TPMS indicator on the passenger front tire for several years, wherein the indicator light with no pressure reading periodically comes on and then resets itself after a few minutes I have had the TPMS sensors replaced. The warning is now coming on more often than not. I have rotated tires, and I even have a spare set of rims/tires with their own TPMS sensors - but the indicator and pressure reading is intermittent on the passenger front, which lead me to the receiver module.
Help much appreciated, and if I am going in the wrong direction, please share.
Do you have LED side markers? Does it only occur at night/when you have headlights on? I started having the same problem, and a bunch of digging got me to people saying the cheap markers put out RF noise that interferes with the TPMS signal. I put some ferrites on my marker wiring right next to the lights, and drove all the way to Utah from Seattle (and back!) without the passenger front going out. Something to consider.
So, I have the same problem. The TPMS system often loses the ability to pick-up the signal from the front passenger tire sensor.
This all started when I got new tires, new TPMS sensors, and new wheels.
I relearned the new sensors, but noticed that the front passenger sensor relearn was stubborn, had to try it many times till it was successful. The new sensors are fresh-stock, genuine GM parts (made by Schrader).
Drove the car after the relearn, and all sensors were reporting the correct tire pressure. After about 20 minutes of driving, the TPMS system could not read the front passenger tire, and --- was displayed, and the TPMS warning light came on.
I reset the BCM DTC (TPMS is done by the BCM), and then a short while later, during another drive, the front passenger sensor did report tire pressure, but then some time later it lost it again, with the TPMS warning light coming back on.
I bought a TPMS Diagnostic tool to troubleshoot, and the battery level of all the new sensors is good, and the tool can read the tire pressure fine, so I don't think the new sensors are the problem.
From reading the GM Service Manual, the RCDLR (Remote Control Door Lock Receiver module has 6 antennas (around the car) that pick up the 433 Mhz radio signals from the 4 TPMS sensors (and also the key-fob remote for unlocking/locking and starting authorization)
The RCDLR is located on the back-wall of the rear cargo compartment, on the interior, covered by the rear trim panel. The RCDLR talks to the BCM (thru a CAN bus), sending it the sensor ID#, the tire pressure, and the sensor battery status. The BCM then determines if the TPMS system is operating correctly (The BCM checks if each sensor transmits to the RCDLR ever-so-often if it detects that the wheels are turning), and sends the tire pressure info to the Instrument Cluster for display.
The RCDLR uses the 6 antennas so it can locate where the key-fob is (outside the car, or inside the car), and the 6 antennas are also used to pick-up the TPMS signals, perhaps aiding the TPMS system to identifying which wheel is transmitting from what location.
The bottom line, is that I believe loss-of-signal from the front passenger wheel sensor is the most common problem because it is the furthest away from any of the antennas. I think the different shape of my new wheels block just enough RF signal from the wheel sensor to cause my problem.
My plan of attack is to check the 6 antennas, and perhaps try to move one of them closer to the front passenger tire.
And no, I do not have aftermarket side marker LEDs, or anything like that which can cause RF noise interference to the TPMS.
Last edited by ersatz928; Aug 25, 2025 at 06:01 PM.
So, I have the same problem. The TPMS system often loses the ability to pick-up the signal from the front passenger tire sensor.
This all started when I got new tires, new TPMS sensors, and new wheels.
I relearned the new sensors, but noticed that the front passenger sensor relearn was stubborn, had to try it many times till it was successful. The new sensors are fresh-stock, genuine GM parts (made by Schrader).
Drove the car after the relearn, and all sensors were reporting the correct tire pressure. After about 20 minutes of driving, the TPMS system could not read the front passenger tire, and --- was displayed, and the TPMS warning light came on.
I reset the BCM DTC (TPMS is done by the BCM), and then a short while later, during another drive, the front passenger sensor did report tire pressure, but then some time later it lost it again, with the TPMS warning light coming back on.
From reading the GM Service Manual, the RCDLR (Remote Control Door Lock Receiver module has 6 antennas (around the car) that pick up the 433 Mhz radio signals from the 4 TPMS sensors (and also the key-fob remote for unlocking/locking and starting authorization)
The RCDLR is located on the back-wall of the rear cargo compartment, on the interior, covered by the rear trim panel. The RCDLR talks to the BCM (thru a CAN bus), sending it the sensor ID#, the tire pressure, and the sensor battery status. The BCM then determines if the TPMS system is operating correctly (The BCM checks if each sensor transmits to the RCDLR ever-so-often if it detects that the wheels are turning), and sends the tire pressure info to the Instrument Cluster for display.
The RCDLR uses the 6 antennas so it can locate where the key-fob is (outside the car, or inside the car), and the 6 antennas are also used to pick-up the TPMS signals, perhaps aiding the TPMS system to identifying which wheel is transmitting from what location.
The bottom line, is that I believe loss-of-signal from the front passenger wheel sensor is the most common problem because it is the furthest away from any of the antennas. I think the different shape of my new wheels block just enough RF signal from the wheel sensor to cause my problem.
My plan of attack is to check the 6 antennas, and perhaps try to move one of them closer to the front passenger tire.
And no, I do not have aftermarket side marker LEDs, or anything like that which can cause RF noise interference to the TPMS.
The intermittent nature sounds like a sensor battery issue. New sensors can have batteries that are not well. They could have been sitting on the shelf for a long time or may not work well with the car. I always replace my sensors with genuine GM parts or the correct Schrader part number for the GM sensor (GM uses the Schrader sensor). You may still get a funky battery if the part has been sitting around for a long time but they do work with the car. I used non GM sensors from AutoZone for some track wheels and within a week I was replacing them. I had to pay for tire breakdown labor each time they were replaced, and the second time I replaced them I found the AZ life time warranty only covered one replacement.
The sensors I used are genuine GM, fresh stock, and the TPMS diagnostic tool reads a good battery level, and correct tire pressure from each of the four new sensors. That's why I don't think it is the sensor.
To further validate this, I plan to swap the left and right front tires and see if the problem moves with the tire (bad sensor), or if the problem remains the right front (bad antenna or bad RCDLR).
This is a super frustrating problem, as when there is a TPMS fault, the Active Handling defaults to a very conservative (low) activation threshold, and even modest cornering activates it, really hampering the driving fun.
So, today I verified that it is not the sensor or sensor batteries. I swapped the front left and right tires, and the problem stays at the front right.
This confirms that it is a problem with the TPMS receiver or one of its antennas.
So, today I verified that it is not the sensor or sensor batteries. I swapped the front left and right tires, and the problem stays at the front right.
This confirms that it is a problem with the TPMS receiver or one of its antennas.
Troubleshooting continues....
Everything you’ve described is exactly what I experience. Please let me know what you come up with. I plan to continue troubleshooting mine when I get it out of storage next year, it seems others are having the same trouble.
If I can figure out how to access the receiver, I plan to replace it. The diagram below shows it behind the rear latch assembly, but I cannot see where it is from any photos I’ve found.
Last edited by mcginna; Nov 2, 2025 at 05:54 PM.
Reason: Additional information
Not sure, but I think early C7s maybe had the K65 Tire Pressure Indicator Module, but newer ones certainly don't. This is perhaps another one of the errors I have found in the Factory Service Manual. In pictures I have seen of what is behind the rear bumper cover, there is no K65 module.
In newer C7s, the signal from the Tire Pressure sensors (in the tires) is received by the RCDLR (Remote Control Door Lock Receiver), and then the digital data from each sensor is sent to the BCM module, over a CAN bus.
The RCDLR is located on the back-wall of the rear cargo compartment, on the interior, covered by the rear trim panel. The RCDLR talks to the BCM (thru a CAN bus), sending it the sensor ID#, the tire pressure, and the sensor battery status. The BCM then determines if the TPMS system is operating correctly (The BCM checks if each sensor transmits to the RCDLR ever-so-often if it detects that the wheels are turning), and sends the tire pressure info to the Instrument Cluster for display.
The RCDLR uses the 6 antennas so it can locate where the key-fob is (outside the car, or inside the car), and the 6 antennas are also used to pick-up the TPMS signals, perhaps aiding the TPMS system to identifying which wheel is transmitting from what location.
I think the problem is either a bad antenna, or a poor connection to an antenna, OR the RCDLR itself has an internal problem. My plan is to first check the connectors at the RCDLR, to see if there is any corrosion / oxidation of the connectors which go to the antennas. But, my car is now in storage, this will have to wait till springtime 2026.
Last edited by ersatz928; Nov 3, 2025 at 09:41 AM.
You can't move the antennas. In a previous life I worked on a similar part for a supplier for Chrysler (the key fobs part). Basically the antennas are "calibrated" based on the vehicle because you aren't actually just using one antenna (TPMS isn't either). The reason you have 6, is because it "triangulates" the signals. Your fob and wheels have "zones" and this is why the BCM knows which TPMS belongs to which tire (the antennas can figure out approximate location in space). The fobs actually have at minimum 4 zones. Left side, Right side, Rear, and Inside. This is how you can only open the hatch when you are behind the vehicle (if its working right touching a door with the fob in the back doesn't unlock the car), same with standing on either side and the other side or the rear. The inside is the same, a key outside should deny a start, while a key inside allows a start. Chrysler had a 5th zone for inside the trunk and in fact they would pop the trunk if the key was detected in there and you closed it.
Not sure why I "can't move the antennas"......one of them has to be moved probably a foot closer to the front passenger wheel.
I didn't buy a C7 that can't be driven above 20% of its cornering capability.........I gotta fix this!! (A TPMS error causes a drastic lowering of the threshold where the Active Handling/Traction Control is activated)
Last edited by ersatz928; Nov 3, 2025 at 04:54 PM.
Not sure why I "can't move the antennas"......one of them has to be moved probably a foot closer to the front passenger wheel.
I didn't buy a C7 that can't be driven above 20% of its cornering capability.........I gotta fix this!! (A TPMS error causes a drastic lowering of the threshold where the Active Handling/Traction Control is activated)
It's a field, all the antennas know where the other antennas they create one cohesive RF field. If you move one you mess up the field. Things might not work right, or they might not work at all. The RF module KNOWS the position of the antennas in space (that's what I mean by the calibration). So the antennas are designed to work together in a mesh.
I don't know how else to explain it, RF fields, magnetic fields, and the like are basically black magic. Don't f with them, you get more problems than you solve.
...
I don't know how else to explain it, RF fields, magnetic fields, and the like are basically black magic. Don't f with them, you get more problems than you solve.
When I worked at that company which did the key fobs, we had an "Antenna Guy" he was the engineer responsible for any issues with the RF fields, magnetic fields, LF fields (most TPMS and Passive Entry use LF not RF) and he'd go off explaining some nuanced thing and the rest of us (all engineers) where just like WTF. We had a high level conceptual knowledge on what he was describing but the details eluded us. It's one of the most complex fields. Its why designing anything from Cell Phone towers to WiFi Access Points is difficult, and why we continue to struggle with reliability and consistency of anything wireless.
He did give me a special "boosted" antenna for my 2008 Jeep GC (which didn't come with our system but was compatible so I swapped ours in) that made my remote start work from 1.5-2 miles away in an open area (let's just say when I would go to my night classes at the university I could remote start my Jeep from inside the classroom which was .5 miles away). We also were told when looking for cars in random parking lots at Chrysler (which you use the fobs to set off the alarm since they are randomly parked in a giant lot) to put the fobs under our chin and use our skull as an amplification/direction device. I can't explain why it worked, but it does. Especially if you know where the antenna is "aimed" in the fob.
I am an electrical engineer and worked on RF systems for spacecraft use....so I do know a 'little" about it...
These passive entry system use LF to activate the fob, and the FOB then transmits RF (433MHz) back to the receiver. The TPMS sensors just transmit RF (433 MHz), when they detect that a wheel is rotating, or the tire pressure has dropped significantly.
And they are not that sophisticated; they can locate the rough location (inside or outside the cabin) of the FOB by comparing the signal strength of the RF received from the FOB, by comparing the signal strength from the 6 antennas. It is not like a sophisticated Active Array antenna, which uses electronic beamforming to focus/alter the antenna pattern.
"put the fobs under our chin and use our skull as an amplification/direction device"
That guy was playing you......
Last edited by ersatz928; Nov 4, 2025 at 02:36 PM.
OK....it had nothing to-do with you holding the key FOB higher up........
Nope holding it up high on an extended arm did not yield the same results (in fact holding an arm over your head in the air pointing it forward was worse). Believe me we all thought this was BS, but based on experience, it wasn't.
TPMS Receiver location
