Idle Control Unit - Rebuilt

Works With:1986-1991
Manufacturer:Quality Aftermarket
1 Review
1 Review
Proposition 65: This product may contain chemicals known to the state of California to cause cancer, birth defects, or other reproductive harm.

The idle control module is commonly referred to as the "idle computer" or "idle relay" or "idle control unit"—and is located behind the right tail light on all 1986-91 Vanagons and Vanagon Syncro with Digifant fuel injection systems. Although the name implies it can only affect idle, this unit can also cause running issues off idle as well. For more info on the idle control system and how it works, please read this article.

Rebuild procedure details:

GoWesty spares no expense with these rebuilt units. We only use A+ quality cores for the rebuilding process—if the unit has suffered any moisture damage, it is scrapped. We want to ensure that the rebuilt unit you receive is simply the best product money can buy, period.

First, each unit is bench-tested, using the following procedures:
  • Custom test fixture that simulates all relevant engine conditions (key on, start, idle, AC, power steering, water temp, RPM)
  • Careful observation of each effect above and its relevance to actual idle control valve performance
  • Verification of unit's ability to control idle speed within 5% of 880 RPM
Then each model is "ruggedized" through the use of a hardening epoxy, which means that component connections are strengthened to better withstand the weather, temperatures, and vibrations found in harsh applications—in other words, these units are actually better than the originals.

Installer beware: Changing out any one part of your EFI system that is faulty with a new or rebuilt part may cause worse running because other settings may have changed over time to compensate for the faulty part you are replacing. Following the base-line settings procedure in the Bentley manual is required after installation. Also please read our return policy related to electric and electronic items.

Idle control unit (ICU) in 86-91 Vanagons. Where is it, how do I replace it?

Replacing the ICU requires some dexterity, attention to detail, and patience; but no special tools. The only part you have to remove to get to the ICU is the right rear tail light lens. Here is how you can find it and replace it:

1) Remove the four screws holding the right (passenger) side tail/stop/reverse/turn signal lens to the body and move the assembly out of the way.

2) Look straight back with a flashlight and you will see the control unit siting with the plastic housing pointing up. On Syncro models, it is a bit trickier to see and replace because the fuel filler conduit is right in the way.

3) Using one hand and working blindly, pull straight up on the unit AND the plastic electrical plug that it plugs into; do not try and unplug the unit from the plastic electrical plug at this point. The plastic electrical plug that it plugs into is dove-tailed into a separate plastic bracket, which is the part screwed to the body. Wiggle the whole thing while gently pulling straight up until it comes off the bracket.

4) Once you have separated the plastic electrical plug from the plastic bracket, you can pull the ICU and plug closer to the tail light lens opening in the body with fuel injection wiring harness still plugged into it. Now you can use both hands to unplug it from the harness. It is helpful to gently pry the unit off the plastic plug with a flat screwdriver.

5) Be careful when you plug the new ICU back in that none of electrical connectors are pushed out of the electrical plug-that is a common mistake that leads to the misdiagnosis of a good ICU as being bad. Once the new ICU is plugged in, you will have to work with one hand, blindly to slide the plastic plug dove-tails back into the matching dove-tail slots in the plastic bracket.

They were originally made for Volkswagen by VDO, but have been discontinued and are no longer available new. This unit is rebuilt, and sold on an exchange basis, with an additional $100 core deposit added to the price listed. You are required to return your old rebuildable unit or forfeit the $100 core deposit.

To return your core, please visit our return portal. Enter your order number and postal code, and choose core return to receive an RMA and return instructions.

Important note: This is an electrical/electronic part, and our standard electronics return policy applies. Please view our Return Policy here
Spreadr Button