Engine system service required and check engine light

[ADriggs26]

I have a 2001 s60 with about 167,000 miles on it. I get an intermittent check engine light and engine system service required light. I have had a Volvo dealer tell me that the brake pedal position sensor is bad and that is the reason for the engine system service required light. I ordered one and it is on its way. As for the CEL, I have had several codes pop up including: cylinder 1 misfire, ambient air temperature sensor, and a thermostat problem. I have changed my spark plugs and coils. All wires to the plugs are good. These lights drive me nuts and I have no clue what to do now. Possible ETM failure? Any thoughts?

[scot850]

What codes have you had? If you can post them here, it may throw us a clue.

When did you last change your thermostat and Engine temp sensor? When the temp sensor stars to fail, it can give weird fail codes.

Neil

[ADriggs26]

P0073 - ambient air temperature sensor circuit high
P0301 - cylinder one misfire detected
I lost the paper with codes on it and it mwntioned a thermostat malfunction. I haven't noticed any difference in the engine temperature or overheating issues. I have never changed my thermostat or temp sensor.

[precopster]

Never seen a BPPS cause a CEL on dashboard. BPPS is a "silent" code that will also stop cruise control from working. The CEL will be the misfire on cylinder 1.

If the engine coolant sensor came up in a scan it will certainly cause rich mixtures. Best to use an OEM Wahler 90degC and Genuine Volvo sensor.

[scot850]

Also make sure the thermostat is the correct temp range for the car. I have seen some aftermarket thermostats that have different opening temperatures. If you have a Volvo one then you should be good on that point. I'm trying to think if there is a common point that can cause possible 'false' fail codes, but really would help if we had the full list if it is possible to get that.

Neil.

[ADriggs26]

I remember now that the engine coolant sensor is one of the other error codes. I ordered one and I will see if that works. Hopefully the BPPS and the coolant sensor will cause the lights to finally disappear. They've been intermittent for months now.

The thermostat I can order and replace when I do the other sensor.

Sorry I am new to this forum. I read a lot on here but I never posted and figured posting could help me figure it out. So thank you kind stranger!

[scot850]

That is why we do this. Thanks is all that is needed and a 'success' message is also good when we get there as it helps all the users to learn.

I also run an older P80 (2000 V70R) and I've said it before, but the local dealer foreman recommended changing the thermostat every 2-3 years as they just wear out. Perhaps it is a Canada thing too as we get such a huge temperature range?

These P2's seem to last well if run over long distances. I've seen a couple locally with 500,000km+ for sale (over 300k miles).

Good luck!

Neil.

[abscate]

I might have this wrong but isn't the fuse on the brake pedal shared with some climate components which can fail? I vaguely remember someone having AC trouble and knocking out his cruise.

Check fuses, in any event - always cheap and easy.

[ADriggs26]

Update: I found out my endings coolant temperature sensor wires did lot have the black plastic tubing around wires so I taped those with electrical tape. Since I unplugged the sensor, I unplugged the battery and "reset" my car's computer. I have had no CEL but my engine system service required light came back on yesterday. I happened to get my BPPS in the mail and replaced it. The light went off and I have not had any lights since. I'm still waiting on my thermostat and temp sensor, both should come today.

[precopster]

Most cars have no 7mm tubing on that sensor due to heat degradation. Tape doesn't give any thernal relief to the wires due to the airgap the 7mm tubing creates.

In any case it looks like you're on the way home. The thermostat can be ordered through Amazon as a 48639 Stant Xact stat 90deg C which comes as a Wahler OEM in Stant packaging.