Electrical: Replace ECU, ECS and Climate Control Capacitors

This article shows you how to replace capacitors on your ECU, ECS and Automatic climate control display.

Suggested Tools

• Soldering iron
• Solder with flux core
• Solder braid (for solder removal)
  • or desoldering iron with integrated vacuum pump
• Philips screw driver

Parts

Purchase -55C to 105C rated capacitors, and look for long life versions that cost a little more. The ones I found are double to triple the lifespan.

Capacitors can be purchased at DigiKeyI have added part numbers for the 1000hr 105c capacitors. They are also available in 2000 and 3000 hr ratings. --Evilncarnate 11:57, 22 November 2010 (EST)

Climate Control Display Repair

I found C9 was a 47uF 50v instead of 16v in 2 units I repaired. (they were out of a 1992 and a 1993) Even if you had a 16v there, it should not be a problem to use the 50v, so I changed the parts list below. --Darkninja 17:04, 2 September 2012 (EDT)

Capacitors for Automatic climate control

• 1 x 4.7uF 50V (C5) (Digi-Key PN: P5566-ND)
• 1 x 47uF 16V (C4)(Digi-Key PN: P5528-ND)
• 1 x 47uF 50V (C9) (Digi-Key PN: P5570-ND)
• 1 x 470uF 25V (C10)(Digi-Key PN: P5543-ND)
• 2 x 10uF 16V (C11,C17)(Digi-Key PN: P5134-ND)
• 2 x 220uF 25V (C14,C15)(Digi-Key PN: P5541-ND)

Diodes for D5,D6,D7. (Digi-Key PN: 1N4004) Generic 1 Amp diodes.

Resistor for R-38 (Digi-Key PN: PPC1.0W-1CT-ND) 1.0 Ohm 1.0 Watt resistor

Step 1

Remove Center vents, use two flat head screw drivers to lift up the hidden tabs inside the vent and a third flat head screw driver to pull the vent out. This will give you access to the top screw holding the automatic climate control display.

Step 2

Remove radio and any trim that's in the way of the climate control display. The display has three screws holding it, I've circled it in red in the pictures below.

Step 3

It's difficult to remove the display out without scratching it, so I suggest putting masking tape on it. I didn't have any tape so I cut the useless white plastic piece that's hidden behind the radio trim. This makes removal much easier. Before you can remove your display unit out, you'll have to disconnect two connectors at the back and also move the black plastic box below it -- this black box is held on with four screws. I believe this black box is the climate control brain.

Step 4

Remove 10 screws from display unit.

The burnt fishy smell. Capacitor c15 failed and leaked onto diodes D6, D7. The writing on the diodes burned off.

Initially I thought my VFD unit was damaged because it had two burned marks on the right, apparently this is normal so don't be alarmed. Those rubbery buttons should be removed so they don't accidentally get burned by your hot soldering iron.

Step 5

Take note of the capacitor's size, voltage rating and location before you desolder anything. Also observe the capacitor's polarity as it must be soldered in the same direction. Now that you've recorded all that information desolder the VFD and remove. This particular task took me many hours using the braid desolder method. I suggest using a better tool such as a desoldering iron with integrated vacuum pump to make the task faster/easier.

Additon by Darkninja - This step is easily the hardest of this project. I found that even with a desoldering iron, it was extremely difficult to detach even one side of the VFD. Be sure to use an alligator clip on the leg of the VFD that you are desoldering to keep from heating up the display itself too much. Then (after desoldering as best you can) you'll need one hand to hold the circuit board, one hand to hold a soldering iron to all 3 pins of 1 leg, one hand to gently apply pressure to the VFD away from the board, and one hand to pry the leg up at the same time. --Darkninja 17:04, 2 September 2012 (EDT)

Step 6

Using new 1N4004 1 amp generic diodes I replaced diodes D6 and D7. Polarity matters, be sure to solder them in the same direction as mine.

In case you have other components damaged here's some pictures of my display unit circuit boards.

Extras Some people have reported R38 to be burned up. Here's a pic of mine and I put a bag of 1 watt resistors beside them to illustrate that the original resistors are probably a bit smaller than 1 watt rating.

Step 7

Solder your new capacitors in, solder in your VFD back in and reassemble and you're good to go.

ECS Capacitors Repair

Capacitors for ECS

• 1 x 0.47uF 50V (C16)(Digi-Key PN: P5562-ND)
• 13 x 1uF 50V (C17,C20,C18,C19,C14,C24,C25,C26,C27,C30,C31,C29,C28)(Digi-Key PN: P5563-ND)
• 3 x 47uF 16V (C10,C23,C32)(Digi-Key PN: P5528-ND)
• 2 x 47uF 50V (C1, C5)(Digi-Key PN: P5570-ND)

Step 1

Your ECS is located in the passenger side (assuming RHD vehicles) trunk area almost to the very rear. It's held on by three screws. My screws were on very tight so I had to remove many plastic trim panel pieces to gain good leverage.

Step 2

Open up the tabs and separate shell casing. Remove two screws and separate board from casing.

Step 3

This is what my ECS look liked. Everything was still in good order, no damage. Take note that all 19 electrolyte capacitors polarity all face in the same direction.

Step 4

Note capacitor location, sizes, etc. My technique for this task was to solder wick using a braid each capacitor before bringing it to a vice. Once the board was secured on a vice I took some needle nose pliers and wiggled the capacitors free while heating the ends. I should mentioned that I grinded my soldering tip to a very sharp point so I could insert it deeper. You might want to print this picture so you know where the desoldering points are located.

Step 5

Here's the board with the capacitors removed. You can see some of the silkscreen marking the locations of capacitors removed.

Step 6

The final project with the new long life capacitors installed. Reinstall back into casing, screw it back on, etc.

ECU Capacitor Repair

Capacitors for ECU.

• 1 x 47uF 50V (Digi-Key PN: P5570-ND)
• 1 x 100uF 16V (Digi-Key PN: P5540-ND)
• 1 x 22uF 50V (Digi-Key PN: P5568-ND)

Step 1

Disconnect negative terminal on your battery. Your ECU is located behind your radio and is secured on by three bolts. You need to remove the side trims to gain access.

Step 2

Using a 10mm wrench remove one bolt on the passenger side, and two bolts on the driver's side. Pull the ECU out and then disconnect the ECU harness. Be sure to unlock the ECU clips before pulling. I find it helps to use a flat head screw driver when pulling the connector. Don't pull on the wires as you may damage your harness!

Step 3

If your ECU has never been open, those screws might be on there super tight. To avoid stripping the four black screws use a cordless drill and put a lot of weight behind it so the bit doesn't slip.

Step 4

Remove the cover and remove four more screws holding down the circuit board. For removing the capacitors I would use the same technique I used with the ECS capacitors removal. First suck the solder out, and then pull the capacitors out while heating the ends. Don't forget to note which capacitors are located where.

Step 5

Install new capacitors. I intentionally left mine long so it will make future removal easy. This is now my third set of capacitors for preventative maintenance.

Step 6

Reinstall screws, case lid, screws again and finally reinstall into car. Reconnect ground battery.

Here's a picture of some of the tools I used. Soldering braid wicker tape is that blue circle thing with copper braid sticking out. The brown bottle is liquid flux, I initially used that to coat the wicker tape for easier sucking but I don't think it was necessary at all.