Chrysler Crossfires after 20 years | IN SEARCH OF YOUR PASSIONS

These are the things I can remember off the top of my head after owning a couple of Crossfires and working on them myself. I love the Crossfire, but like any 20-plus-year-old car, they definitely have their quirks. If I’ve forgotten anything, let me know

The Crossfire Coupe and Convertible share almost all of the same drivetrain and electrical trouble spots because both use the Mercedes M112 3.2L engine and, on automatics, the Mercedes 722.6 transmission.
The Convertible adds several top-specific problems.
These are problems I would put at the top of the Crossfire list

1. RCM — this is a big Crossfire weakness
The Relay Control Module, next to the battery, is notorious for relay and solder-joint problems.
It can cause:* crank but no start * no crank * intermittent stalling * fuel pump not operating * car works one day and refuses the next * seemingly unrelated electrical symptoms
The RCM as one of the first places to investigate for intermittent no-start conditions.
This is one Crossfire part where I actually think having a **known-good spare RCM** is reasonable.

2. Crankshaft position sensor The M112’s crank sensor is another well-established failure.

The classic symptom is: Cold engine → starts normally → gets hot → suddenly dies → will crank but not start → sits/cools → starts again.
This is why Crossfire owners frequently keep a replacement CPS available. If either of your cars ever develops a mysterious hot stall, this moves very high on my diagnostic list.

3. The automatic transmission’s biggest weakness isn’t necessarily the transmission
The Mercedes 722.6 is actually a pretty robust transmission, but the electronics attached to it cause a lot of Crossfire problems.
Conductor plate, It contains the transmission speed sensors. Failure can cause:
* P0715 * P0720 * impossible turbine/input speeds * gear-ratio errors * harsh shifting * transmission stuck in one gear * limp mode * “BAD GEAR”

Crossfire owners repeatedly report conductor-plate speed sensor problems producing limp mode.
That is essentially the family of problems you encountered with your Coupe before replacing the conductor plate/valve body.
But there is another 722.6 problem I would watch closely:

4. The 13-pin transmission connector – The electrical connector going into the transmission has sealing O-rings.
When they leak, ATF doesn’t necessarily just drip onto the ground. It can wick up the wiring harness.
And where does that harness go? To the TCM under the passenger floor.
If you find actual transmission fluid around or inside the TCM under the floor it got wick up the wire.
So the preventive sequence is:
722.6 connector → wiring harness → passenger footwell → TCM
Even after fixing a transmission problem, I’d inspect the TCM connector for old ATF contamination.

5. Clogged cowl drains are more serious than they sound – There are drains under the windshield cowl.
Leaves and debris clog them. Water then backs up and can enter the passenger compartment. Owners specifically report water reaching the components beneath the passenger floor, including the **amplifier and TCM**.
For cars in South Florida, I’d put this unusually high on the preventive-maintenance list because of rain, humidity and vegetation.
I check these drains every six month, more if you park under trees. It’s almost free insurance.

6. Alarm siren = mysterious dead battery – This one surprised me by how consistently it appears in Crossfire discussions.
The factory alarm siren contains its own rechargeable batteries. After 20+ years they can leak internally, damaging/shorting the siren circuit and creating a parasitic battery drain.
Crossfire owners repeatedly identify the alarm siren under the windshield cowl as one of the most common sources of battery drain.
So: Crossfire suddenly kills batteries sitting → don’t immediately blame the battery or alternator. Check parasitic current and the alarm siren. You can take out the alarm fuse.

7. Alternator and voltage regulator – This one is particularly relevant to electrical diagnosis.
A failing alternator/regulator can produce much more than a battery warning.
Low system voltage can cause: * ABS light * BAS/ESP light * transmission errors * spoiler weirdness * instrument errors * poor starting
There are documented Crossfire cases where replacing the alternator voltage regulator eliminated BAS/ESP symptoms because low voltage was upsetting the other modules.
For diagnosis, I’d want approximately: **Engine off after resting:** ~12.5–12.7 V **Engine running:** normally around 13.8–14.6 V
Crossfire owners report roughly 14+ V as the expected running charging voltage.
This is important: don’t diagnose the Crossfire’s computers until you know the electrical supply is healthy.
If the voltage is below 14v either the battery is bad or the alternator. Try a new battery and see if the voltage issue goes away, if it doesn’t the alternator works but is bad and will damage the battery.
Either way Crossfire computers wont work well below 14v

8. M112 oil leaks – The M112 itself is a strong engine. What it loves doing when old is leaking oil around the top.
The common areas are: * breather covers on top of valve covers * breather-cover RTV * valve-cover gaskets
These leaks are widely reported on the Crossfire/M112. A small upper-engine leak usually isn’t catastrophic.
The typical clue is oil running down the engine and eventually producing an oil-burning smell or smoke from the exhaust manifold area.
There is crud under thos valve covers, best to clean them up at 100K if they leak, which they almost always do, Install Catchcan from needswings.com

9. Front suspension bushings – This is another one I would almost call an age maintenance item now.
The rear bushings of the front lower control arms deteriorate.
Symptoms: * vague steering * steering-wheel vibration * clunk * poor alignment * uneven front tire wear * steering wheel doesn’t feel centered/stable

One Crossfire technical discussion describes the rear front lower-control-arm bushings as a very common problem and suggests that, by now, nearly all original cars are candidates regardless of mileage
Also inspect: * lower ball joints * upper ball joints * steering damper * sway-bar bushings/links * engine/transmission mounts

10. Cooling fan/control module – This can masquerade as a much more serious cooling problem. The electric radiator fan or its electronic controller fails.
Then: Driving at speed = temperature looks okay but Sitting at idle/traffic = temperature climbs
You can diagnosis a good fan motor but failed fan control operation.
So if either car ever runs hot primarily at idle, check fan operation before assuming thermostat, water pump or head-gasket trouble.

11. Spoiler problems –
The rear spoiler system has several failure possibilities: * microswitches * wiring where the hatch flexes * motor * gears/mechanism * BCM input * ABS/wheel-speed information
Failed or displaced spoiler limit switches causing improper operation, including spoilers that rise but won’t retract.
The first choice is not to replace the spoiler motor check microswitches, mechanism and wiring first. – Many things cah cause the spolier not to work correctly.

12. Convertible-specific: rear window separating – This is one of the better-known Roadster problems.
The bonded rear glass can separate from the fabric top.
That’s something I’d physically inspect on Crossfire1: Look carefully around the entire perimeter of the rear glass from both inside and outside.
Catch separation early rather than waiting until the glass is hanging from the top. I use 3M black 5200, it last forever, the top with wearout before the glass falls off.
If you have a small tear you can put some material on inside and glue on iside with the 5200

13. Convertible hydraulic system – The Roadster top uses a hydraulic pump, lines and cylinders plus multiple position/interlock switches.
Typical failures include: * hydraulic leakage * low hydraulic reservoir * leaking cylinders/hoses * weak/no top movement * tonneau/rear deck won’t move * top starts its sequence and stops
* trunk becomes locked because the top cycle didn’t complete – Leaking hydraulic systems and top sequences stopping partway through.
Before assuming the pump is bad, I would check: **fluid level → leaks → cylinders/hoses → switches/interlocks → pump.**
This thing is a nightmare. I converted mine to manual.

14. Convertible trunk-latch/interlock switch – This is a particularly annoying one. The top controller needs confirmation that the trunk is closed before operating the roof.
A failed trunk-latch microswitch can therefore make a perfectly healthy top refuse to work. Owners have documented this failure and the resulting top/spoiler interaction.
So: **Top doesn’t work ≠ automatically hydraulic failure.** There are a lot of interlocks.

15. SKREEM / immobilizer – The Killer – The security/immobilizer electronics are another source of: key recognition trouble
* no-start * starts briefly and dies * fob synchronization trouble
But because RCM, crank sensor, battery voltage and SKREEM can produce overlapping symptoms, I would **diagnose rather than parts-swap**.
Motor turns over, may even run for a few second and then dies.You need to send your keys and SKREEN unit that sits behind Instruments to someone to reprogram them or bypass them.

More on Oil and Auto Tranny
Your standard Chrysler Crossfire 3.2L V6 engine is 195 cubic inches. More precisely, the Mercedes M112 engine is 3,199 cc, which converts to about 195.2 cu in. It is a great little engine. I get 320 hp out of one of my non-superc charged engines. That is one hp per CC. this is Ferrari performance territory.. You need to treat it like the high performance engine because it is. Just because you bought the car cheap does not change its needs.

Engine Oil if you drive you car moderately, change you oil every 5 or 6 thousand miles. Use ONLY Mobil 1 European Car Formula Full Synthetic Motor Oil 0W-40, and only this one. This engines metals require it.
The only time I change this, when I buy a Crossfire the first oil change that last a few weeks is Valvoline Restore & Protect Full Synthetic 0W-20 Motor Oil – I use this to flush the engine. and I change the Filter every time, use only Mann Filter HU 718/5 x Cartridge Oil Filter. Again these engines are very picky, You can use a cheaper oil or filter and damage your engine and you wont even know it.

Auto Tranny Oil

Your automatic Crossfire with the Mercedes 722.6/NAG1 transmission, I would use ATF that is explicitly approved for Mercedes-Benz MB 236.14.

The original Chrysler specification called for MB 236.10 or MB 236.12 fluid, and the Crossfire owner’s manual confirms that. But MB 236.14 is the later fluid specification and is the one I would use for a service today.

Good choices include Mobil ATF 134, Shell ATF 134, Fuchs TITAN ATF 4134, Pentosin ATF 134, Motul ATF 236.14, and Valvoline ATF Pro 236.14. These are on Mercedes-Benz’s current MB 236.14 approved-fluid list.

I prefer the Pentosin ATF 134 – It is not Cheap especially when you have to throw it away.

Let me tell you what happens, I buy auto Crossfires cheap every year, because the owners never changed the tranny oil and filter. Then the Tranny stops shifting, goes into limp mode. Crud gets into valve body. When flushing does not work sometimes I have to replace valve body and flush tranny several times before I get it working correctly. You can also have issue with oil traveling up the cable to TCM. You would never believe it until you see it. It can take several tranny service to fix the problem and most mechanics wont waster there time. Save your car, if you are close to 90k change the oil and filter. If you are over 130k miles you may be getting close to problems soon. and need to clean it out.

My pick: Pentosin ATF 134, Others are Mobil ATF 134 (MB 236.14) or Fuchs TITAN ATF 4134. Valvoline ATF Pro 236.14 is also perfectly appropriate if that’s easier to obtain. Never mix oils – pick one drain, refil, drain again, refill, – Do it about three times and you pretty much have one oil in there.

If you can find the older fluid, it is better than newer fluid for Crossfire. The original Chrysler specification called for MB 236.10 or MB 236.12 fluid, and the 2004 Crossfire owner’s manual confirms that. But MB 236.14 is the later fluid specification and is the one I would use for a service today.

One important detail: on the 722.6, correct fluid level and fluid temperature are nearly as important as the fluid itself. The level needs to be checked with the proper service dipstick at the appropriate transmission-fluid temperature. You need to get a dipstick, but actually measuring fluid level is complicated. I actually drain pan and replace with known amount and then add as needed based on computer reading.

Tires are another big one. A lot of Crossfires have spent years sitting because the previous owner got tired of dealing with the car, couldn’t get it running, or simply stopped driving it. I bought one that had been sitting under a tree for about five years. It was full of leaves and looked like it was going to rot away. It took me about three months just to clean everything up. The tires looked okay, but they weren’t. Age can destroy a tire even when the tread still looks good.

Pay especially close attention to the hoses. If one old cooling-system hose fails, chances are the others aren’t far behind. The same goes for vacuum hoses. Take a really good look at everything, and if the hoses appear original or you have no record of them ever being replaced, it may simply be worth replacing them as a set. On a 20-year-old car, even little things like the coolant expansion tank can become brittle and crack. None of these problems is necessarily a big deal by itself, but they add up. You can drive an overheating car and kill it.

So when you buy one of these cars, assume that it may have been sitting for a long time and go through it thoroughly before depending on it. Don’t immediately assume that a newly purchased 20-year-old Crossfire is ready to be your daily driver. Vet it first. Check the cooling system, charging system, transmission, brakes, suspension, tires, hoses, belts and electronics. Once you sort one out, though, it can absolutely be a good daily driver.

What I would proactively to avoid issues
1. Clean all windshield/cowl drains.**
2. Inspect/disconnect or replace the original alarm siren** if it is still 20 years old.
3. Inspect RCM condition** and consider keeping a good spare.
4. Carry a quality crankshaft-position sensor.**
5. Check battery and **charging voltage**.
6. Inspect the **722.6 13-pin connector for ATF leakage**.
7. Pull passenger carpet/cover and inspect **TCM and amplifier for moisture/ATF**.
8. Inspect front lower-control-arm bushings and ball joints.
9. Check M112 breather covers/valve covers for oil seepage.
10. Confirm radiator fan engages properly.
11. Test spoiler automatically and manually.
12. On Convertibles inspect rear-window bonding.
13. On Convertibles inspect top hydraulic reservoir/lines for leakage.
14. Exercise the top and verify every stage works correctly.
15. Address any sticky ignition-key behavior immediately rather than waiting for it to lock completely. Initially you can wiggle the keys and steering wheel and drive home, but it will get worse and one back your will be stuck with a lock steering wheel.

Lots of good information here https://www.crossfireforum.org/forum/ and of course there are a ton of youtube video.

There’s a lot of information here, but it should give you a good idea of the issues you might run into.

Keep in mind that previous owners may have already taken care of some of these problems. In fact, when you buy a Crossfire, it’s pretty common to get a box of spare or replaced parts along with the car. Try to figure out what the previous owner has already repaired or replaced before you start buying parts or chasing problems that may have already been addressed.

So, you just bought a 20-year-old car. Here’s the first thing to remember: you probably don’t know how old the hoses and belts are, what maintenance has been done, or what has already been replaced.

That’s really the philosophy I use with these cars: when you’re already working in an area, inspect everything around it and take care of the other aging parts while you’re there. If you’re doing brakes, inspect the wheel bearings, hoses, bushings and suspension components at the same time. If you’re working on the cooling system, look at all the hoses, clamps, reservoir, thermostat and related components. You don’t necessarily have to replace every part, but remember that much of what’s on the car may have been there for 20 years.

I own two of them. One of mine is extremely dependable—I get in, start it and go. The other runs very well too, but it’s a little more temperamental. If I’m in a hurry or absolutely can’t afford to get stuck somewhere, I take the more reliable one. That’s just part of owning an older car until you really know it.

Until you have gone through all the systems, I would treat a Crossfire more like a classic car than a modern used car. Expect to work on it. Expect to learn it. And get yourself a decent OBD-II diagnostic scanner. You may even go through a couple of inexpensive scanners before finding one that communicates properly with all the Crossfire modules.

One useful trick is that some diagnostic equipment works better when the car is identified as its Mercedes relative rather than as a Chrysler Crossfire. Much of the Crossfire is Mercedes underneath, particularly the drivetrain and electronics. Depending on the scanner, selecting a compatible Mercedes configuration can sometimes give you access to information a generic Crossfire setting won’t. A good scanner can read far more than just check-engine codes—it can show transmission codes, input and output speeds, sensor data, live engine information and other module data. The better I’ve gotten at diagnosing these cars, the more valuable that information has become.

And if you’re not a mechanic, that’s okay. The more you learn about the car, the better equipped you’ll be to talk to someone who is. The Crossfire is a bit of an orphan. You can take one into a typical chain repair shop and sometimes find that nobody there has much experience with it. Many younger mechanics simply haven’t been exposed to Crossfires or to the older Mercedes systems underneath them. Finding someone familiar with Mercedes vehicles from that era can make a huge difference.

One of the things I actually love about the Crossfire is that it’s still somewhat old-school. It’s computerized, but it isn’t so computerized that you can’t work on it yourself. You can still replace coils, sensors, hoses and mechanical components without needing factory programming for everything. With a decent scanner, some tools and a little knowledge, you can diagnose and repair a surprising amount of the car yourself.

So enjoy it—but remember what you bought. It’s a 20-year-old sports car. Go through it carefully, learn its history, fix the neglected items, and earn its trust before you depend on it. Once you do that, the Crossfire can be a very enjoyable and surprisingly dependable car.

I always say you don’t drive a Crossfire, You wear it.

Good luck with it.

I will add more stuff here as I remember people ask me.