Dash Warning lights going crazy! S70 GLT Topic is solved

S70GUY · Post by **S70GUY** » 23 Mar 2025, 18:13

2000 S70 GLT

Got this cars for 450 dollars, was left for a long time, and While I was trying to take it to the street, it doesn't rev above 4K and I have these lights on the dashboard. Any help would be helpful, the only code it throws at me (I have a generic OBDII scanner) gives me the code P1618, and since it's my first Volvo, I'd like to have it in optimal condition.

Post by **scot850** » 23 Mar 2025, 20:23

So lets' look at the different lights:

Up Orange arrow is a transmission fault light.

Is the parking brake on? Not sure on US spec cars is that is giving a brake failure warning or if it is just a reminder the parking brake is set.

Radiator red light beside the Orange up arrow is for low coolant level. Is the coolant level in the header bottle correct? The Hi mark is approximately the seam half way up the header bottle. If the level is correct, carefully lift the bottle and see if the level sensor is plugged in. There is a connector to disconnect the header bottle for removal. Sometimes if the bottle has been removed they may have forgotten to re-connect it. Other options are the wires to the sensor are broken, the level sensor is stuck in the bottle from sitting.

Check Engine could be anything. Code P1618 is an ECU fault with the ECU.

ABS light could be any of many issues. It can be the ABS module has failed which would also explain the lack of info on your dashboard for mileage.

Looking at all those issues, my first port of call would be to remove the ECU and TCU modules in the black box behind the RH headlight. Google hoe to so this. It is quite possible you have corrosion on the pins of both of the boards to the main harness connections below them or critter damage to the wiring in that area.

Neil.

Post by **matthew1** » 24 Mar 2025, 13:18

I'm with Neil. It's likely something electrical. Battery could be weak, ground could be loose or corroded.

But do check coolant level.

Post by **misha** » 24 Mar 2025, 13:37

Ignition switch?

Post by **Clemens** » 24 Mar 2025, 16:49

And as usual, a bad battery. Even if the car starts off the battery and runs with the alternator functioning, these P80 Volvos can throw weird error codes if the battery is towards end of life. Symptoms are similar to a bad ignition switch. Btw, we're not talking about the key part of the ignition, but the electrical switch at the back of the key barrel.

S70GUY · Post by **S70GUY** » 24 Mar 2025, 17:03

From Could it be that all this (including transmission) is due to the battery?

Post by **scot850** » 24 Mar 2025, 17:32

It is possible. Battery needs to be above I think it is 10.5V under load. A battery can show it has 12V but have a bad cell and drop way down when loaded. I'd like to hope it is that easy. I guess I should have had you starting with the easy stuff first, Sorry! I realize now I did not include that option.

Neil

aeg · Post by **aeg** » 25 Mar 2025, 17:28

Coolant light is not due to the battery. Check the coolant level before you drive it again!

Is the orange arrow actually lit up, or is it just a reflection of the sunlight?

S70GUY · Post by **S70GUY** » 26 Mar 2025, 13:52

Orange arrow it's blinking, I wanna know how to remove it

Post by **scot850** » 26 Mar 2025, 16:53

You need to get a code reader that can read Volvo codes including the ABS unit. The ABS unit has speed information the trans uses so if there are ABS issues it could cause trans issues. A good code reader can also check trans codes as well.

We need to know what those codes are to give a chance to figure it out.

Neil.