2005-2008 Subaru Forester stuck in Valet mode

Last Update: May 23, 2023 @ 18:17 Information subject to change.

A v-e-r-y common (and irritating to a host of owners…) issue with 2005-2008 (and apparently later) Subaru factory security systems is it gets into Valet mode, and is difficult or seemingly impossible to reset back to “normal” operation. This is esspecially true if the remote has been lost, failed or simply had the battery replaced.

Here are instructions to program a 2008 remote.

This Service Note describes the issues, attempts to explain what’s happened, and how to fix it.


Normal operation with the remote locks (also arms the system) and unlocks the doors. When the system is armed, there was not (on this car at least) any Security light blinking in the gauge pod. The horn chirps and turn signals flash when the remote is used, though this stopped working sometime after I purchased the car. The remote still worked. There is apparently a way to disable the horn chirp and turn signals flash, but it’s not (obviously) mentioned in the Owner’s Manual.

A web search found …”unlock the car, then press and hold the lock and unlock buttons at the same time. You can cycle through 3 or 4 different options. Light flash only, light flash and chirp or nothing at all.”

Some time ago (before winter 2018), the remote started to require a hard press to lock and unlock (see the cause below), and one day, something happened, and the Security light started flashing twice per second. The remote buttons no longer locked or unlocked the doors. The doors could be manually locked and unlocked, and the engine started and run with no problems. When the engine was running, the  Security light stopped blinking.

Checking in the Owner’s Manual indicated that the system had switched to Valet mode.

To activate/deactivate Valet mode, open the driver’s door and press the unlock button for at least two seconds. You’ll get your turn signal flashing lights back when locking and unlocking via the remote. More important, perhaps, is to recognize that when the headlights don’t flash, you’re in Valet mode and that you’re only locking the doors, not arming the alarm system.

Examination of the remote showed that the push buttons had separated from the circuit board. This was an easy fix with the tools we have here.

The Problem…

The Owner’s Manual assumes that the remote is functioning, and pressing the Unlock button while opening the driver’s door is supposed to clear the valet mode. On-line searches suggested that this can also be done by holding the manual unlock button (on the driver’s door), and opening the driver’s door is also supposed to clear the valet mode. This option is provided when a remote is not available.

The problem is that its unknown if the remote is actually transmitting anything.  Holding the manual unlock button as described above does not cause Valet Mode to clear.

The Security Unit appears to be working, as the Security light is flashing.

Because it’s in Valet mode, it does not appear to be possible to set the unit to program mode using the instructions in the Owner’s Manual. There is a solution , scroll down …

Disconnecting the battery (which resets the ECU) has no effect on the Security Unit (SU).

Getting at the Security Unit (SU)

In situations like this, locating and evaluating the SU is a useful step. It’s located behind the glove compartment, next to the AC fan assembly.

The glove compartment assembly is secured with nine screws, and
when removed, exposes the SU and fan assembly.
Removing and cleaning or replacing the cabin filter is a good idea
while you are here…esspecially if you’ve never done it.
The SU is mounted with two M8 nuts. Remove these.
Unclip the wiring harness. If you remove the harness connector, the Security
light stops flashing and the engine can still be started. This again indicates
that the SU is functioning.
There’s two plastic clips that allow the SU circuit board to be removed, as shown above.

What we were hoping for was a reset button of some sort: unfortunately there is not.

Examination of the SU components show a micro-controller (probably a 16-bit Microchip product) run by a 4.18MHz crystal, with a small EEPROM (IC502) for SU parameter storage. Most IC part number identifiers are not visible. There is a 4012B signal processing PIC device that handles the input from door sensors and remotes, and output to door locks, gauge pod and immobiliser system.

If the SU is not plugged in,  the Security light does not flash which is expected, as the SU controls it. The engine starts and runs, and the doors can be manually locked. All other vehicle systems appear to be functional.

And now the Solution!

After months of occasionally trying everything read in Google searches, the solution was found.

To recap, Valet mode won’t exit if a programmed remote is not present and functional. It also seems that it is not possible to enter Program mode when Valet mode is active. The Owner’s Manual does not indicate this is possible.

This is not correct: it is in fact possible to enter Program mode when Valet mode is active. Below is the sequence of operations you do to fix the problem.

Open the remote and remove the battery: this is to ensure that the remote has to be reprogrammed to the SU. Make sure that the battery in the remote is replaced correctly, with the -ive side facing the circuit board.

In the Owner’s Manual, it states Program mode is activated as follows …

  1. Open the driver’s door and sit.
  2. Close the door, and proceed immediately to step #3.
  3. Use the key to switch LOCK-ON-LOCK 10 times in 15 seconds, stopping at LOCK. If Program mode is activated, the horn will sound once. DO NOT REMOVE THE KEY.
  4. Open and close the driver’s door.
  5. Press and hold any remote button. Within 2 seconds the horn will sound twice, indicating that the remote has been programmed to the SU.
  6. Remove the key, and the horn will sound 3 times, ending Program mode.

The common problem occurs in step #3. Make sure that you are actually switching LOCK-ON-LOCK. If you don’t get back to LOCK, the activation sequence will fail.

NOTE: Activating Program mode then immediately removing the key to deactivate it CLEARS existing remote entries. A remote that previously locked and unlocked the doors stops working, and you’ll have to do the whole programming sequence again.

Thanks for reading. Since you are here, do have a look around our website.

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