Quick question, getting a 2-2-1 on the diagnostic unit A hole 2. According to:

http://www.troublecodes.net/Volvo/

This is "Heated Oxygen Sensor(Rich mixture/part throttle)." Before I drop $$ on a new sensor, is there anything I can do to fix this otherwise? I know the sensor has not been replaced in the last 70,000 miles we have owned the car.

Thanks.

 

that error is rarely actually the O2 sensor. more likely, its something else causing the mixture to be richer than expected, this could be anything from vacuum leaks to a sketchy MAF to...

wait, hole TWO? fuel injection is hole THREE. hole 2 is ABS or cruise control or something. if it IS hole 3 in fact, 2-2-1's trouble shooting starts with...

• Check air and vacuum hoses according to Checking air and vacuum hoses .
  Are air and vacuum hoses OK?
• Check exhaust system for leakage.
  Is exhaust system OK?
• Checking mass air flow (MAF) sensor ground terminal
  -Ignition off.
  -Disconnect connector from mass air flow (MAF) sensor.
  Connect ohmmeter between connector terminal 1 and ground.
  The ohmmeter should read approximately 0 Ω.
• Checking signal from mass air flow (MAF) sensor
  -Clean and treat mass air flow (MAF) sensor's connector for oxidation according to Checking wiring and terminals. Permanent faults .
  -Start engine.
  Connect a voltmeter between 3 on rear of the mass air flow (MAF) sensor connector and ground.
  The voltmeter should show approximately 2.3 V.
• Checking vacuum hose to pressure regulator
  -Ignition off.
  -Disconnect vacuum hose from pressure regulator.
  -Check that the hose is not blocked by blowing into it.
  Is the hose OK?
• Check fuel pressure (complex factory procedure deleted, requires fuel pressure gauge)
• Checking input and output signals of LH2.4 ECU
  -Connect control module to breakout box.
  -Insert fuse 1 (940) or 31 (960).
  Connect voltmeter between ground mass air flow (MAF) #6 and ground
  -Take readings with ignition on and with engine idling.
  The voltmeter should read approximately 0 V for both readings.
• Connect voltmeter between signal mass air flow (MAF) #7 and ground.
  -Take readings with ignition on and with engine idling.
  The voltmeter should read approximately 1.4 V and 2.3 V respectively.

 

Sorry, it was the 2 hole on the A side. That website said to use the 2 hole and the A2 has the plug in it, B2 has nothing in it. I tried the 3 hole on the A side and got nothing. Then, I tried the 3 hole on the B side and got 1-2-2.

Of the holes that have a lead to plug into, here is what all I am getting:
A2 - 2-2-1
A3 - nothing
A6 - 1-1-1
B3 - 1-2-2
B5 - 1-1-1

According to:

Engine and OBD Diagnostic Codes

A2 is said to be used for the fuel system as well, so looks like I will need go through and do all your recommendations to try to clear this up.

 

omg, huge apologies for that. had my nose in a 1990 MBZ 300E this past couple weeks, and it uses pin 3 for ECU diagnostics... it *IS* pin 2 on the Volvo.

that troublecodes.net site is useless. the one you linked on that last message is way way better. note that 2-2-1 for a REGINA system is somewhat different than for a LH2.4 system, the troubleshooting procedure I quoted was for the LH2.4 bosch system. regina uses a square coil, bosch uses a conventional round one.

 

yeah, diagnose the cause of the fault code.

 

I too have the B2 code 1-2-2. But am not sure which/where this "Air Temp Sensor" (according tohttp://www.troublecodes.net/Volvo/) is or what it might be conntected to? BTW, my AC compressor is not coming on, but does work? Any ideas?
Thanks!
Jay
1993 940T Wagon

 

this is a much better reference:
Engine and OBD Diagnostic Codes and OBD Diagnostic Codes

the "A" block pins 2 and 6 have the LH2.4 (injection) and EZK(igntion) codes. B block, if any, has stuff like ABS, climate control.

according to this table, A2 2-2-1 is fuel trim is too lean, which can be from intake manifold air leaks, low fuel pressure, etc.

 

Thanks for this Pierce:

I have a Code 1-2-2 (not 2-2-1) on Block B. My question is what does this Air Sensor do and what is it connected to? I do not have a ECC or a dash outside Temp Gage?

 

do you have a memory power seat? might be that. "Position sensor for motor 3, absent or flakey" ... diagnostic procedure says to first check the connector "C" on the seat controller (under the seat). Not sure, but motor 3 may be the rear height motor.

 

So, to give an update on this, long over due I know. To recap, Service light was on, getting a 2-2-1 and the OBD1 A2 hole. Today, I looked all over for any vacuum leak, using the propane, carb cleaner, and starting fluid method and did not find anything. I noticed many of the small hoses had cracks in them so I replaced them. I also put a cap on the fitting at the air intake manifold for the hose going through the firewall which I am assuming operates the air duct controls since there could easily be air leaks in there I might now notice. I then decided to reset the car by disconnecting the battery for 5 mins. I then, reconnected the battery and read the code off before even starting the engine, 1-1-1, good. I then started the car and ran for a very short time and the service light stayed on. I then reread the code, 1-1-1. I then drove the car around the block and the light shut off after 2 minutes. After getting back home, I reread the code 1-1-1. Then I looked up in the owners manual that the stupid light stays on for 2 min after 10,000 miles indicating an oil change. Then I looked up how to reset the stupid thing.

So, hopefully I fixed it although it still runs a hair rough at idle then I would like. I hope it will pass an emissions test now. Anyway, code is cleared for now, will see if it comes back, hopefully not.