Dear Volvo enthusiasts,

Looking for assistance in resolving 2-3-1 and 2-2-1 codes in '93 240 Wagon, LH 2.4. Codes initially appeared after regular maintenance verifying plugs and changing the air filter. Since then, I have changed to new plugs, replaced the air filter again, new O2 sensor and new flame trap. I have checked the hoses for cracks, vacuum leaks, etc. Checked injector seals for leaks. I don't see or hear any vacuum leaks.
Codes erase successfully but re-appear immediately after engine start, and the Check Engine lamp lights on. The engine runs fine, and doesn't "appear" to have any obvious issues.

Any further assistance would be appreciated.

Also, 2-3-1 and 2-2-1 codes are lean/rich mixture at cruise codes. Why are they appearing immediately after engine start and not after the cruising for some time, as their name implies? Just wondering if I'm taking the code names too literally.

Thank you,
Alex...

 

I think you have to re set the ecu by disconnecting the battery and re-connecting...this might work.

 

I would verify the resistnce of the coolant temp sensor, its the blue-red wire (#13) at the ECU ... it sould be around 300 ohms at room temperature.

Also the throttle position sensor should be checked out.

I could also be the air mass meter.

 

Thanks a lot guys. I followed your advice and some others I found in this forum. 2-3-1 and 2-2-1 codes have been cleared.

Maintenance/Checks performed:
-Coolant Sensor verified. Resistance was around 2.4K Ohms, engine temps were around 70C. 300 Ohms is way too low resistance for this temperature, temps should be way higher according to my Bentley book.
- Throttle Switch verified. The connector was dirty with gas deposits.
- Air Mass Meter cleaned with CRC MAF cleaner.
- Battery disconnected and re-connected.
- Disassembled, inspected and cleaned the entire Air Intake system, staring from air filter to the manifold, including all air hoses.
- Throttle body thoroughly cleaned, it didn't contain any obstructions but did have heavy fuel/dirt deposits.

LH codes 2-3-1 and 2-2-1 codes went away.

I drove the car for about an hour, it performed just fine.

I checked the codes and now 2-3-2 code showed up, so the system is still compensating for rich/lean mixture but now at idle. Will continue to troubleshoot but at least the Check Engine light is out.

Thanks a lot for you help guys!!
Alex...

 

I meant to say ~300 ohms at 180 degrees F ...

 

gotcha. Thanks.

Strangely enough, after driving for 2 days, the acceleration has smoothed out and 2-3-2 code once cleared did not return. I am thinking perhaps the IAC valve cleaned itself out? Still thinking of cleaning/checking it but at least the Volvo is happier again.

Thanks for all suggestions.
Alex...