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2001 Volvo P2 ETM Removal and Cleaning Directions Howard Cheng

howardc64@yahoo.com 10/15/2012 Version 1.8

An Update Its been a few years since I’ve posted this direction and it seems many people use it to remove, clean, or replace their ETM. I’ve learned a few things since 2005 when I posted the last version of this direction. Here is a brief summary of the updates

• Volvo developed updated ETM software in 2005 which seems to reduce the unpredictable onset of limp home mode (20mph max) that have stranded many owners. It also seem to enable longer serviceable life from the ETM. With a little bit of knowledge on the construction of this ETM, I’m guessing Volvo simply change the software to be less conservative when detecting errors in the readings from ETM’s internal angle sensors.

• Low cost Volvo computerized diagnostic tool (VIDA/DiCE) is now available for

about $200. This tool contains an ETM test which will tell the health of ETM angle sensors. Volvo also started Service For Life campaign which provides free software upgrades during services (the level of service required seems to differ between dealers). The added effort of running the ETM test is just a few minutes once the technician have hooked up the computer for the software upgrade. So you might ask if they can check your ETM’s health for free or few minutes of labor J See ETM Testing below for reference.

• There is now aftermarket rebuild service to repair this ETM and DIY parts. The

main failure on this ETM is a simple Throttle Position Sensor (TPS). It is not too difficult to replace but does require a little patience. I have now included the directions on repairing the ETM at the end of this document.

Acknowledgement Big thanks to flippu10 on Volvospeed. His directions motivated me to not be overwhelmed by all those pipes and wires at first glance on this job.

Read this before you start I performed this ETM cleaning because I had gotten 2 reduced performance messages at 50+ mph driving. I also felt faint hesitation at extended period of highway speed driving (over an hour). It felt similar to the driving on highway during windy days.

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After the ETM cleaning, my car had more performance and ran really well. I was impressed. It was like having a new car again. But then I got another reduced performance message and all my performance gains after the ETM cleaning was gone. I decided to reset the computer by disconnecting the ETM and the battery. The improved performance magically came back after. I realized it is the computer reset from ETM cleaning that gave me the performance increase and not the removal of slight oily film in the throttle body. Ultimately, my issues was only fixed by replacing or repairing the ETM.

Disconnecting the ETM Picture 6 shows how to disconnect the ETM. It is not necessary to disconnect to battery. However, the starter is near this connection and would have a live positive wire exposed nearby. Just be careful if you don’t disconnect the battery. If you do plan to disconnect the battery, be sure to follow carefully the exact sequence prescribed by Volvo. The Climate Control Module can be damaged if not followed properly. See the Disconnect The Battery section later in this document for reference.

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ETM Testing Volvo’s diagnostic tool (VIDA/DiCE) has an ETM test program. This test can be conducted while the ETM is still in the car. The test basically does the following

• Open and close the throttle 4 times • Compared the 2 angle sensors on each ends of the ETM • If the angle difference is greater then 13 degrees, Volvo considers it bad. I’ve read

people having failing ETMs and only showing 3-4 degrees of difference. Here is the graph showing a good ETM and one that is bad. The first one shows the green/blue lines (sensor value from each of the angle sensors) very close to each other. The bad one is much further apart. The black lines shows the difference between the 2 sensor readings. On the good ETM, the Y scale on the black line is 0 to 0.8 degrees. On the bad ETM, the Y scale on the black line is 0 to ~75+ degrees.

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General Comments • Most steps of this job looks harder than it really is. Most items and connections

you can see removes easily • The turbo pipe feeding the ETM is the single hardest item to remove and

reassemble when doing it first time without experience. I have since learned some nice tricks to make it really easy.

• Took me a total of about 4-5 hours the first time. But I think I spent 3+ hours trying to figure out how to remove and reassemble the turbo pipe from the ETM. I can now remove the ETM in probably 10-20min and reassemble in about the same time. I’ll outline the tips in this document.

Sequence of main components to be removed

• A1. Air pipe connecting the turbo to the intercooler (see picture 1) • A2. Air intake to the air filter box (see picture 1) • A3. electric fan assembly (see picture 2). This step is not necessary. But space is

tighter and maybe more difficult for the first timers. • A4. Turbo pipe from intercooler to ETM (see picture 3). • A5. ETM (see picture 3)

Parts you will need

• B1. ETM to intake manifold gasket ~$3 online (picture 5)

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• B2. Hose clamps with screw for tightening/loosing clamp for about 5/8" diameter hose

• B3. 3 tie wraps that can provide about 1 inch loop • B4. Throttle body cleaner (valvoline synthetic carb+choke+throttle body cleaner

worked well for me) • B5. Old tooth brush to scrub the ETM deposits

Tools you will need

• C1. 1/4 drive + extension + 7mm and 10mm socket • C2. Screw driver handle attachment to the above sockets (may not be necessary.

See "Remove turbo pipe from intercooler to ETM") • C3. T-25 Torx screw driver + T-25 Torx tip/bit (one screw is oriented with no

room for screw driver)

Note The directions will indicate some locations with left and right. Left is driver side and right is passenger side in US models.

Disconnect the battery

• There is a thick red positive wire connection to the starter just below the ETM and the air hose that feeds it. Rather than to take a chance and touch ground, I just disconnected the negative terminal on the battery.

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• Disconnecting the negative terminal requires a very specific sequence. Here is the direction

o Turn everything on your climate control off (AC, fan, heated seats etc..) o Keys out of the ignition o Close all 4 doors, leave the rear hatch open for access to the battery o Wait 15min (climate control unit will continue to run even with keys out) o Disconnect the battery o Reconnecting the battery also requires a very specific sequence that will

be outlined later.

Remove Air pipe connecting the turbo to intercooler (picture 1)

• Loosen clamps at 3 locations (picture 1, hose clamp H1, H2, H3). H2 and H3 are on the rubber pipe connecting the plastic pipe to the plastic piping to the intercooler.

• Take off the 2 T-25 Torx screws (picture 1, T1 and T2). The one near the dip stick don't have enough clearance for a Torx screw driver. So use the Torx tip/bit with a 1/4 drive.

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Remove air intake to the air filter box (picture 1)

• 2 pieces of loosely connected plastic parts

Remove fan assembly (picture 2) NOTE: This step is not necessary if you want to follow tips later on how to work a more confined space during reassembly. You may want to skip this step for now and see if you are able to remove and reassemble without removal. You can always remove this if you need more space.

• Remove the T-25 Torx screw (T3) holding the bracket • Disconnect the electrical connector (E1 and E2) • Cut the 3 tie wraps (W1, W1 and W3) • Remove 2 bolts (B1 and B2) • Un-guide the radiator fluid hose on top of the fan • Take the wiring harness out of the guides on the right side of the fan assembly. • Move the wires aside, take out the dip stick to have more room and pull out the

fan. Have to wiggle a little to get the tabs on the bottom of the fan assembly to clear radiator hoses on both sides of the radiator.

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Remove turbo pipe from intercooler to ETM (picture 3, picture 4)

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• Loosen the clamp on intercooler side (about half way down the lower left of the radiator) and pull the hose out of the intercooler connection.

• Take off the hose after removing hose clamp (H4). I squeezed the crimped part (edge wise along the length of the clamp) on top with a pair of plier and the clamp just popped open.

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• Take off the 2 electrical connectors (E3 and E4). There is a tab to squeeze on both of them before applying pulling force. The top on the black connector is facing up while the tab (doesn’t give much when squeezed) for the grey connection is facing the passenger side and therefore blind. Here are close up pics for reference

• Here is one of the hard steps. Feel and find the screw on the clamp (at the end of the U turn on the turbo pipe) holding the turbo pipe to the ETM. Use the proper tool depending on orientation. Mine was located in the very back (toward the engine block) with the screw head facing left. I had to use a 7mm socket fitted to

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a screw driver handle + extension (to make about 10 inches total) to reach in under the intake manifold. Yours might be oriented different especially if it has been disassembled before. Anyway, your eyes aren’t useful in this task, it is all by feel. Here is a picture of what the pipe and clamp looks like. The clamp in the picure is already loosened and removed from the fitting.

• This pipe will usually be hard to pull off the first time since the factory assembly. It is hard to get good leverage leverage on it. I finally put a screw driver over the U turn on the pipe and pushed down with one hand in front of the ETM and the other under the intake manifold. It came out right away.

• Now you have to twist and angle past the confined space to remove this pipe. If you’ve not disconnected the battery, take the metal clamp off and remove it before removing the this pipe to avoid having a large metal part twisting around the live positive starter wire.

Remove ETM

• Trace the ETM wire to connector and disconnect it (Picture 6) There is a tab on it. Press it and pull out the connector. Here is the picture of the tab with the connector already out

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• Take out 4 ~3 inch long 10mm bolts arranged rectangular pattern around the

throttle body opening hold the ETM to the intake manifold. Need to feel for it and operate in blind. They are just outside of the ETM’s round intake lip. Here is a picture for reference. I found a ¼” ratchet with a deep 10mm socket worked well. Don’t mind my ETM looking different than yours. Mine is undergoing home made contactless angle sensor modification J

• Remember, counter clock wise to loosen (Remember that the ratchet is upside

down so it looks like clock wise if you look down from top of the engine compartment)

• Pop off the ETM. Use slight force to loosen the hold by the gasket. • Some later 2001 cars seems to have the connection cable routed behind a bracket

holding the starter. There are 3 bolts, I just remove the bolt on the engine block and loosen the 2 nuts on the bolt attached to the starter to create enough space for the cable to come out. You can see the 2 rusty bolts attached to the starter in this

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following picture. The bottom bolt attached to the engine block is just visible at the very bottom of this picture next to the light blue paper towel.

• Retighten the starter bracket. There is no need to route the cable behind there later.

Clean the ETM

• Spray and clean the inside round walls of the throttle body + butterfly. Use the tooth brush to get off the more gummed up areas. I wouldn't get the rest of the ETM wet, there is electronics in there.

• Use a gasket scraper or razor blade (gentle and becareful as the surface is aluminum) and scrap off the remaining sticky gasket material on the ETM. Clean this surface with throttle body cleaner.

Reinstalling the ETM NOTE: This step is done completely under the manifold so you will be blind. Get a good look at the parts before starting.

• Put the new gasket on (I put the raised ring on gasket facing ETM, but I heard it doesn’t matter). I put 2 small pieces of masking tape on the front and back of the ETM to secure the gasket so I doesn’t flop around as I get the 4 bolt’s thread to catch. Stick the tape out beyond the ETM body and fold it back on itself to make a little tab to grab hold on to. Just thread a few turns after each bolt catches. Since the 4 bolts are long, there is still a good inch of space between the manifold. Use your fingers to feel around and make sure the bolts are through the gasket. Next, remove the tape.

• Tighten the bolt to 10nm

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• Connect the ETM electrical connector. No need to route the cable behind the starter bracket again. May want to zip tie to cable to something else so it doesn’t get caught in the fan blades.

Installing the turbo pipe to ETM NOTE: This step is done completely under the manifold so you will be blind. Get a good look at the parts before starting.

• This was really hard and took me a long time. The pipe's opening to the throttle body barely fits so you need really good alignment and even force while working blindly upside down without good leverage.

• I use several tricks on this reassembly o First, reassemble the hose to the intercooler. This will help align the fitting

that goes into the ETM. Tighten the clamp. o Loosen the ETM side clamp and drop it to the bottom of the U part of the

hose. Use your fingers to get a good feel whether the lip of the opening is evenly over the entire throttle body. If the clamp is still around the fitting, then you can’t get a good feel. One hand is typically under the manifold while the other reaches down from the front. A good trick is to grease the fitting and ETM opening mating surface. It goes in a lot easier. Apply upward forward to fit it in there snuggly.

o Since you will be doing everything by feel, you should remember there were ribs on the outer lip walls of the throttle body for the turbo hose attachment. If you can feel these, then the hose isn't on correct or fully.

• After the hose is on, put the clamp back and tighten the hose clamp. I put the

screw facing front of the front of the car so I don't have to work a ratchet under the intake manifold next time.

Everything after this is easy. Just reverse the disassembly process with the following additional notes

• If you have removed the fan assembly, then make sure the tabs on the bottom of the assembly fit into the slots on 2 side of the radiator. This is what holds the bottom of the fan assembly. Also be careful working these tabs pass the hoses on both side on the top of the radiator.

Reconnecting The Battery The proper reconnect sequence from Volvo is

• Put the key in the ignition. Turn to position II • Connect the battery

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All the electronics will power up suddenly as the key is in position II. This might seem odd but it is the proper direction from Volvo to reconnect battery. Whenever I disconnect/reconnect the battery on my car, sunroof and a few other electrical circuits don't work after. Just use your remote or door lock button or key to lock and unlock the doors. This resets all the communications on those circuits properly. Repairing the ETM The main failure on this ETM is the Throttle Position Sensor (TPS). There are 2 TPS on this ETM and they are mounted on each end of the ETM body. TPS is a very simple circuit. It is basically a 3 connection variable potentiometer. 2 of the connections are the power (+5V) and ground and the third connection is the variable voltage output depending on the throttle plate’s rotational position. There are 2 TPS for redundancy. The original TPS fail because they are contact based. There are metal fingers that swipes along a resistive element as it rotates providing variable output voltage. Unfortunately, the metal contact fingers wears out the resistive element and provide inaccurate readings. You might have experienced an old audio amplifier that produces a bunch of clicking noises when you turn the volume knob (also a variable potentiometer) It is the same problem. There is an aftermarket replacement TPS that is contactless. It operates using magnetic field to provide the rotational angle. The replacement procedure basically replace only a single TPS on the original ETM and feed the output of new TPS to both sides. Redundancy is removed but the reliability increases greatly. You have several options to do this repair Xemodex (xemodex.com) will do the rebuild for you for $500. You can also google “ETM Sacer TPS” to find part source ($140 at https://www.midwest-abs.com/ETM-Sacer.php or on ebay) and directions. It does take a little patience to remove the green epoxy to expose the contacts to solder the new TPS on. A common trouble people have found is the contacts on the ETM are alloy and difficult to get a good solder joint. People have had bad contacts after the repair. Be sure to solder the ETM contacts well to avoid this problem.