Hi, my 91 745 turbo has been trying to tell me something lately. It took a few cranks to get it started sometimes. Most of the time, it's normal. NO check engiine light on. However, it gives codes. 232 is more often. sometimes it gives 214 (ignation RPM signal erratic). The FAQ says "Adaptive heated O2 sensor control (94-up)" for 232. I noticed that there are a few codes(231, 435, 436, 511, 512, 521, 522) related to the O2 sensor. The discriptions are all a little bit different. Mine is not califonia car. Does 232 in my car mean the sensor is on the way out? I guess that 214 is probably related to the ocational hard to start situation. Do I need to replace the O2 sensor and the crankshaft RPM sensor now, or I can let them go a little? Thanks. Erwin

What OBD sockets (#2 or #6) yield what code?

Indeed, if your crank sensor has never been changed, replace it ASAP.

The 2-3-2 code is a mixture too rich/lean (you'd think it could tell you!). More common culprits are vacuum leaks, fuel pressure regulator, AMM, O2 sensor.

-Ryan
--

Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars

Thanks for your reply, Ryan. #2 gave 232 and #6 gave 214. The record shows that the crank sensor was changed 05/2005, so was the control unit (I assume that it means the ignation control unit). However, I have a brand new crank sensor in my spare box. I will change it if it gives me 214 again. I'll change the O2 sensor asap, that could be still original. Erwin

Hmmmm.... try clearing the codes and then see if the crank sensor code comes back. I've had aberrant crank sensor codes once or twice.

Definitely probe around with a meter before writing off the O2 sensor. Again, several problems (affecting the mixture) can cause this code.

Good luck!
-Ryan
--

Athens, Ohio
1987 245 DL 314k, Dog-mobile
1990 245 DL 134k M47, E-codes, GT Sway Bars
1991 745 GL 300k, Regina, 23/21mm Turbo Sway Bars
Buckeye Volvo Club

A quick re-cap of my problems:
• This is a few days after a brief overheat (thermostat problem, fixed)
• Puts out a 232 more often than occasional, once or twice a 214
• Once or twice hard to start
• Popping sound at the rear end, about once every second

Things checked so far:
• Brand new FPR a few month old
• Vacuum hoses (bellows) all tight, new air filter
• New fuel filter

O2 sensor test data from today (procedure according to Lucid’s post (written by Bruce Young?):
• With O2 sensor connected to ECU ---- 0.1, 0.78 constantly cycling
• Open loop (O2 sensor output disconnected ---- 0.03
• Fake Full Lean ---- 0.9
• Fake Full Rich ---- 0.019 (with 1.5V battery)
• 0.017 (with human connection to 12V)

This looks to me it’s a good O2 sensor. However, is the O2 sensor known to have intermittent problems?

I also took this opportunity to test my spare O2 sensor using the propane torch method (never dare to do this before!). While the probe is glowing hot, it reads 0.9 with the torch on and 0.15 off. This surprised me. I thought it should be just opposite. When torch is on the probe, less O2, lower reading.

I assume that the popping sounds indicate a rich condition as it's cycling. Does it mean it's too rich? Any idea why?

If the rpm sensor has never been changed,I would change it.
I would check the values of the o-2 sensor.

Thanks, I'll do that. According to my readings in the archive, it could literally anything, feul system, air supply system, coolant temp sensor etc.. Maybe this can shed some light on it. Just a few days ago, my thermostat stuck open and my temperature gauge went to the red region and higher for a short time. The steam from the engine blow most of the coolant out of reservoir cap. Since there is still much coolant in the block, everything seemed to be fine afterward. This is what promped me to do the Loss Of Coolant warning light. Do you guys think that this might be somehow related. Erwin