{"id":410,"date":"2016-07-09T08:36:45","date_gmt":"2016-07-09T13:36:45","guid":{"rendered":"http:\/\/sprinter-camper.com\/?p=410"},"modified":"2021-02-19T16:40:20","modified_gmt":"2021-02-19T16:40:20","slug":"fixing-sprinter-abs-pump","status":"publish","type":"post","link":"https:\/\/sprinter-camper.com\/fixing-sprinter-abs-pump\/","title":{"rendered":"Fixing the Sprinter ABS Pump"},"content":{"rendered":"

When I was test driving the Sprinter van, both the ABS (Anti Lock Braking System) and ASR (Anti Slip Regulation) warning lights went on after a short drive. The seller of course explained that he had fixed this issue just days before and that he couldn’t understand why it’s coming back. Since I flew in to pick up the van and the seller also still had the replacement pump (and the price of the van was good) I decided to take the risk. Long story short: I drove the van about 7,000 miles without ABS, replaced the ABS pump and electronics from the spare unit I had twice without success. As it turned out, the previous owner tried to replace a malfunctioning ABS pump with another defective one.<\/p>\n

The real fix however turned out to be pretty simple, technically speaking and surprisingly cheap – given that a Mercedes seller would charge you over $2000 for a new ABS system alone, not including labor for installing it. Much more cheaper are used ABS pumps that can be found on eBay<\/a> (That will still run into below problem at one point if they haven’t been serviced before). Make sure you look for the right ABS unit, Mercedes used different part numbers through the model years and van types. The 2006 Sprinter 3500 part number for example is A0004465789 [@eBay]<\/a><\/p>\n

The Mercedes specific ABS code that the scanner gave me was C1401 (ABS return flow pump)\u00a0which led to the pump itself.<\/p>\n

First, a simple test to check if the ABS pump is working is listening closely when you turn the ignition to position 2 (not starting the engine). You should hear the ABS pump motor spinning. This is the initial test that the van’s computer is performing to see if the ABS system is functional. If it doesn’t detect a running motor it won’t turn off the ABS warning light on the dash.<\/p>\n

If you can’t hear the ABS pump making some noise the next step would be to apply 12V directly to the pump motor to see if the problem is in the electronics or wiring to the ABS pump or the pump motor itself. The ABS pump is accessible from the top of the engine bay and even better if you remove the driver side head light (for left hand drive Sprinters) – the arrow in the picture below points to the ABS pump.<\/p>\n

\"ABS<\/a>
Location of the ABS unit in the T1N Sprinter engine bay<\/figcaption><\/figure>\n

You don’t need to remove the whole ABS pump to do this test. The ABS consists of two parts: the silver piece with the brake lines connected, which is the hydraulic system with the pump motor and the black box bolted in front which contains the electronics.<\/p>\n

\"2006<\/a>
ABS unit used in a 2006 Sprinter 3500<\/figcaption><\/figure>\n

The black box is bolted on to the hydraulics with six torx screws. You can access most of those screws from either the top or through the headlight cavity. If I remember correctly only one of the bottom screws are is bit more tricky to remove. I was successful by using a small ratchet with a torx bit and accessing the screw from below. Now with the electronics part removed, you’ll see the two power connectors for the pump motor. It doesn’t matter where you apply plus and minus, the pump will run either way. The video below shows how it should sound – I took the video after I fixed the ABS pump in my Sprinter van.<\/p>\n