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Tom, just curious if the ICM you replaced that had 11.8 V (high) and 4.7V (low) has spark plug wire towers all on one side? The spare ICM I tried on my '90 Reatta came from a 1992 Regal with 3800 engine, and all six plug wire towers are on the same side. That ICM delivered 11V on the +10V Supply Out (644 circuit), and 6.5V on the Cam Signal In (633 circuit). After re-installing my original ICM that has three plug wire towers on each side, I now have 9.59V on the A-B lead Cam Signal In (633 circuit), and 9.97V on the +10V Supply Out (644 circuit). That is back in spec. I noticed it takes a really strong magnet in close proximity to the cam sensor in order for the ECM BC5 Cam Signal to change from 10V to zero. With no magnet present, the BC5 lead reads 10V to ground with my meter, and reads zero V when a magnet is present. I tried a pickup tool magnet and magnet in a work light, and they weren't strong enough. Luckily when I put the cam sensor back in and started the engine, I'm getting a reading around 10.2V. I left the meter on for a test drive, and during fast acceleration the meter reads 9.7V, and while cruising or coasting, it is around 10.2V. And there has been no check engine light and the engine is running smooth! In my previous post, I mentioned I was reading 4.9V all the time on the BC5 lead, but I had the test wire on the wrong pin. Conclusion: With a good ICM that provides close to 10V on both the supply and Cam Signal In circuits, and a replacement ECM, my E041 code is gone, and engine is running great.

I'm having the same exact problem with my 1990 Reatta, with intermittent E041 code, and engine missing when the light comes on. I've had the car 6 years. When I first got it, I did have to replace the cam magnet. I just checked, and the magnet is still in place. I have swapped cam sensors, ignition module, and just swapped the ECM with a spare. I'm still getting intermittent E041 code. It does seem to be somewhat thermal related. The code used to come on more after reaching operating temp. After the ECM swap, it is happening more often before reaching operating temp. I'm currently seeing A-B (633 circuit) voltage of 6.5V on the lead from the ICM, so I will put my original one back in and see if that helps. I disconnected the ECM connector and put a 30 AWG wire-wrap wire (from the former Radio Shack) with the end stripped into the BC5 connector before re-seating the plug. That way I can measure the BC5 lead to ground with my meter. It is only reading a steady 4.9V, and is supposed to pulsate or average around 10v with the engine running. I also noticed that if I hold a magnet up to the cam sensor with it removed but still connected to the harness (engine off, but key on), there is no change on the BC5 lead (still 4.9V). I anticipated the voltage going to 10v moving the magnet close and away from the sensor. I tried both cam sensors with the same result. Maybe installing the original ICM will put 10V back on the A-B lead, and hopefully will react to a magnet at the sensor.

I would like to use the washers and "C" clip method described to eliminate the extra slack in my emergency brake cable too on my 1990 Reatta. The turnbuckle is adjusted all the way and the cable still sags. I can't quite picture where this is done, and what it looks like. If someone could provide a diagram or picture, it would sure help. Thanks!

I found this post very helpful as I needed to replace a bad brake pump relay on my 1990 Reatta. I discovered what others noted that the Buick replacement relay was not an exact fit, and did not interlock. From relay numbers listed in this post, NAPA was able to cross reference to their Echlin AR174 ABS Relay, and it is an exact match with the original, for $13.36. http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/ABS-Relay/_/R-ECHAR174_0460182791 The left relay position under the hood is intended to be empty in the 1990 Reatta. The middle position is the Brake Pump Relay, and the right is the ABS Main Relay. The fuel pump relay on the 1990 Reatta is located in position "C" in the passenger side fuse panel relay block.

I can confirm that my 1990 Driftwood Reatta has original 35 mm front axle nuts. With 167K miles, the bearing noise was loud going straight and turning left, but quiet when turning right. The forum was correct in that the passenger side bearing was the bad one when turning right is quiet. My local AZ only had 34 mm and 36 mm impact sockets to rent out, so I had to purchase their non-impact Great Neck OEM/35 mm axle nut socket, part number 25153 for $17. Here is a link, and it is also available on Amazon. http://www.autozone.com/autozone/accessories/OEM-35-mm-axle-nut-socket/_/N-255s?itemIdentifier=864642_0_0_&target=shelf In summary, here are the primary tools you will need to replace the Reatta front hub/bearing assembly: 1. 35 mm axle nut socket (1/2" drive) for front axle nuts. 2. 18 mm socket for two caliper bolts. 3. T55 bit (3/8" drive) for three front hub bolts. I did reuse my front axle nut, so hopefully there won't be any issues in doing that. Regards, Rich

Don, The ECM is located behind the glove box. You have to take the screws out from around the glove box to remove it. Going back to your step#1, do you still have a code for the cam sensor? I suggest writing down all the current and history codes, then clear the codes to see if any come back again. I had a cam sensor code when I first got my '90 Reatta, but it still ran fine with it. The problem in my case was not the cam sensor, but missing magnet in the cam gear. I had to replace the missing magnet to fix that problem. I'm thinking you have multiple problems. I'm not sure about the smoke. Daniel is right, it could be bad mass air flow sensor. Mine went bad last year and my engine would stall, stutter, or not restart very easily. I had no engine codes. In my case, if I tapped on the MAS it would change - engine would die if running. I replaced the MAS and it has run great ever since. I hope that helps.

I just had the same thing happen to the right-side license plate bulb on my '90 Reatta too. Just remove the one screw and remove the lens. Then make a hook with a piece of wire and fish the hanging bulb out the rectangle hole. I used JB Weld to glue the broken off socket back together. The push-and-turn plug still works in the socket. Another way to get to the hanging bulb is next time you remove the taillight assembly to replace any burned out #194 bulbs, you will have easy access there.

It was a beautiful day yesterday to attend the Reatta owner lunch in Anderson, IN. It was an enjoyable lunch and visit with other Reatta owners. We had a good turnout with about a dozen cars there. Barney, thanks for sharing your technical expertise with us! Photos courtesy of Jim Campbell.

After reading this forum posting, I was worried about the availability of parts. However I was pleasantly surprised when my local dealer, Ed Martin Buick on MI Rd in Indianapolis (317-872-9896) was able to order all the parts, and they actually came in from Lansing within 3 days! These are the parts that were ordered and came in for my 1990 Reatta, front cradle: #1627359 Insulator (cushion/bushing) #1626368 Spacer #10409029 Bolt #11516075 Package of 10 metric nuts for the insulator stud bolts Interestingly, when I asked the service department at the dealer for an installation estimate, they said I should take it to a local body shop. When I can save up enough, I will do that. 1990 Driftwood/tan coupe BCA #45409 / RDIV #1074

My 1990 Reatta coupe clunks when going into reverse. Are you saying a bad motor mount can cause this, and that is what the dog bone is? The top mount looks OK. I'm not sure I've seen the lower ones.

Ronnie, sorry that I didn't give you the credit for suggesting the intermittent open in the brake switch circuit. That is exactly what it was. Thank you! RichardD, that is a good point about the fuse rating. Since I don't know the specs on the transistor that blew on the BCM, I'm being cautious and fusing it as low as I can for now. If I find the 0.5A slow-blow doesn't hold, then I will reevaluate and try a slightly larger fuse rating. Thanks, Rich

I wanted to follow up and report that the cruise control problem is now fixed! Here is what I had to do: 1. I repaired my BCM that was damaged from the BS05 test by swapping a blown transistor inside, with one from the second blown BCM. I made one good one out of the two. It was the unmarked transistor next to Q22 that controls circuit 402. 2. I installed a fuse holder in circuit 402. A 0.5A fast-blow fuse blew, but a 0.5A slow-blow fuse holds OK. The vacuum solenoid only draws 0.35 A, but the fast blow fuse did not hold up due to a spike. 3. I replaced the cruise control vacuum release valve. The original had electrical contacts that had an intermittent open when the contacts were closed. I'm not sure what this switch does, because it is not the brake switch connected to BCM input B171. This connector has a purple and pink wire that I don't see on the schematic. The cruise still didn't work reliably. 4. I cleaned the brake switch contacts connected to BCM input B171 that had high resistance and an intermittent open when the contacts were closed. This is in the brake light switch with two sets of contacts, and is the second (or rear) contact with gray and brown wires. This was causing the cruise to cancel by itself and not set/resume. The weird thing is that every time I did the B171 input test, it always showed the Hi/Lo transition in the display. However, when I checked the contacts with an ohmmeter, they had high resistance and an intermittent open. Root cause: Dirty contacts on the brake switch B171 BCM input caused the cruise to cancel by itself and not set/resume. It was intermittent. Caution: The BS05 BCM override test does something to sink too much current through the transistor in the BCM and it blew on two BCMs that I tried. I recommend not doing this test unless you have a 0.5A slow-blow fuse installed in the 402 circuit first. MC_Reatta, thanks for your help and suggestions. Your comments got me thinking, and on the right track to solving the problem. Problem solved, case closed.

MC_Reatta, I finally got time to perform the test you suggested. No short appears to be the problem, as I measured 40.2 ohms on the 402 circuit (BCM pin 2B2) to ground, for the vacuum solenoid coil resistance. I discovered that the BCM case is not at chassis ground, so the measurement was in reference to chassis ground. Additionally, I measured 81 ohms across the 402 and 403 circuits (BCM pins 2B2 and 2B12). That is the series resistance of both the vacuum and vent solenoid coils at the BCM. I also measured 20 ohms across the 398 and 399 circuits (BCM pins 2A10 and 2B9), which is the servo position sensor coil resistance. So, all connections at the cruise control servo are making it right to the BCM connector. In summary, here is what I think the problem is: 1. There is a primary problem I haven't yet found (possibly the brake switch/vacuum release valve). 2. In the process of troubleshooting, the BS05 test damaged two BCMs so far, and there is no longer a pulse even with the B002 test.

Yes, there is a code set: b673 That confirms what I said about the BCM signal 2B2. There is no output on the B002 test. This lead controls the vacuum solenoid in the servo. I still think the BCM override "BS05" test caused this. Rich

I'm attaching shop manual page 8A-34-1 that shows the schematic of the BCM and cruise control servo. Rich Reatta Cruise circuit.PDF