Check Engine Light Retrieval

Written by Jason Pearce from
Pearce Autotech

Check Engine Light On?

..This article is pertaining to the Saab LH 2.4, 2.4.1 and 2.4.2. systems. These systems were used on 900 classic and 9000 models from 1988 to 1993. The LH 2.2 system has no provision for self diagnostics without expensive testers. Well the dreaded check engine light has come on and you don't know what to do. Don't worry it can be easier than you think.

.....Step one is to make yourself a switched and fused jumper wire (2.5 amp fuse). The fuse is important, test sockets have been known to have been wired wrong and or jumpers stuck in the wrong slot. While we're on the subject of burning things up the 900 models with 2.2 LH (all 1985-87 and 1988 turbo) have a 3 pin test connector that looks just the same as the LH 2.4 connector. Please don't be tempted to pull codes if you see this socket. Grounding this plug will let the smoke out of your system relay and possibly your LH computer.

.....Now that you have made your jumper wire you have to locate your test socket. On 88 model 900's you will find it located on the right side of the engine compartment close to the recirculation door for the ventilation system. For the 1989 and up 900 classic you will find the socket under the back seat in the center on a galvanized bracket. If you have a convertible you will find it on earlier models underneath the rubber boot between your center console and the stick shift. If it's a later model it will be under the back seat just under the right side panel. (See diagram)

Now we can get down to pulling codes.

1. Ground pin 3 on the 3 pin test socket in engine compartment or pin 2 on test connector under back seat depending on your model.

2. Turn on the ignition to the run position (the check engine light should be on)

4. Now turn your jumper switch to the "on position" check Engine light should go out.

5. Now watch the check Eng. light you will see a short flash. Turn your jumper switch back to the "off position"

6. This is when you get your flash code; the first flash of the check Engine light should be a long one the next will be short flashes with a pause in between numbers. These short flashes are your code after the code has been shown there will again be a long flash. These long flashes tell you the code is starting and ending. After the long flash your ready to pull the next code. Turn your jumper switch to the on position and watch for another short flash then quickly turn it back off again the second code will now be shown in the same manner as the first. The system may store up to 5 codes. When all the codes have been read you will get a long flash over and over.

7. To clear codes once you have read them turn your jumper switch back on and wait for 3 short flashes then turn the switch to the off position. And remember to use this as an aid but always refer to your manuals.