Dear All,

If someone would know how to clear dash lights for Check Engine & ABS (without taking the bulbs out), I really appreciate your help.

My car: 1994 850 Turbo T5 Sedan, Auto Tranny, 143,000 plus miles
Fuel Control System: Motronic 4.3

1. Check Engine:
I pulled out the codes from the diagnosis terminal in the engine compartment and got: 3-2-5 (ECU memory loss), 4-3-6 (Non-existent in Haynes manual), and 4-3-5 (Heated O2 sensor response slow). Sometimes I can make the light go away by disconnecting battery for some period, but this time it's here to stay. It was gone for a while after I replaced the plug wires, distributor cap & rotor, but then it came back on the other day. I have not noticed any drivability problems (except for gun-powder odor at higher RPM).

2. ABS Warning:
Here are the codes I got: 1-4-1 (Faulty brake pedal position sensor, shorted to ground or supply), 1-4-2 (Faulty stop light switch, open circuit or short circuit), and 3-1-2 (RH front wheel sensor open or short). This one used to disappear after engine start, but after I pulled the codes it is here to stay. I followed Haynes' procedures and at the end I got 1-1-1 (system normal), but the dash light remains lit.

O2 sensors and wheel speed sensors are ridiculously overpriced, so I am not buying them unless the car quits.

Best regards to all,


JPN

 

I have exactly the same problems with my 94 Turbo sedan w 82000 miles. Car drives like new so driveability and braking are not affected or do not appear to be. ABS-Tracs light comes on intermittantly and CEL stays on. Im a newbie but posts and archives seem to indicate that this is a relatively common situation. Having codes read on Friday but do not plan to do any work or replace parts at this stage. Anything comes clearer Ill post it.

 

Have you tried to clear codes using the presidure in this site?
If so what code comes back right away?
http://www.troublecodes.net/Volvo/

 

Thanks for the link, handy to have. Dealer says that cel code on mine is the anti-knock sensor. They reset it but said it might show again if I don't use 92 octane or better. Whats with this as owners manual specifies 91 octane? However I'm sure that dealer I bought it from was probably putting in cheapest grade. Cel showed midway through the first tank of 91 I put in it.

 

Hello Mr. Tech,

I hope you're doing well. I am freezing in Chicago.

Anyway, the ABS is back to where it was, the light turns off after start up (and I feel a click on the brake pedal), and it comes back on when it feels like it. I tested to see if the ABS would work when the light is gone, and it did work (I tested it on a rainy day and on a deserted road). When the light turns on, it goes inoperative. I cleaned all wheel speed sensor tips with brake cleaner and checked electrical wire connections and all seemed to be in good condition. But as so many people are having similar problems, I think this should be a manufacturer's recall item. ABS is such a critical safety feature, and if it fails so easily then the manufacturer should be responsible. I bet there are hundreds, if not thousands, of Volvo drivers who are irritated with that ABS warning light.

As for the check ENG light, I'll do the serpentine belt soon, and at that point I'll disconnect the battery and remove the 2 ECMs (One is Bosch (German) and the other is Aisin-AW (Japanese)). Haynes says to wait at least 5 minutes before removing the ECMs, after disconnecting the battery, which isn't a bad idea as the power relay may keep some power to the ECMs even with the battery disconnected. Even if it clears the light, however, I have a feeling that it would come back on. O2 sensor is another item that seems fragile.

Thank you again and I'll update you when there's a progress.

Best regards,


JPN