TopGum

My cel light came on a couple days ago. The code reader (great to have btw), gives me this code "P0122 Throttle position sensor, low circuit." The car will not idle at all sometimes or VERY poorly at other times. What does "low circuit" mean? There is also some real bad hesitation driving on the freeway. At first when the cel tripped, the VSA and "!" lit also. Would this all have to do with a bad throttle position sensor?

EricL

For a list of the codes:

http://www.acura-cl.com/forums/showthread.php?t=134111



P0122:

Page 11-57 of 2001 CL service manual

"Low Voltage in TP Sensor Circuit"

1. Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then turn the ignition switch OFF.

2. Turn the ignition switch ON(II).

3. Check the throttle position with the scan tool.

Is there approx. 10% when the throttle is fully closed and approx. 90% when the throttle is fully opened?

YES -- Intermittent failure, system is OK at this time. Check for poor connections or loose wires at the TP sensor and at the PCM.

NO -- go to step 4.

4. Turn the ignition switch OFF.

5. Disconnect the TP sensor connector.

6. Turn the ignition switch ON (II).

7. Measure voltage between the TP sensor 3P (three pin) connector terminals No. 1 and No. 3 (EL note -- there are the outer most connectors far right/left (NOT CENTER == #2)

Is there approx. 5 V?

Yes - Go to step 8

No - Go to step 14

8. Turn the ignition switch OFF

9. At the sensor side, measure resistance between the TP sensor 3P connector terminals No 1 and No 2 with the throttle fully closed. (No 1 are shown as the left most and center terminals when viewed from the terminal side of the male terminals)

Is there approx. 0.5 - 0.9 K ohm?

YES -- go to step 10

NO -- Replace the throttle body

10. Measure resistance between the TP sensor 3P connector terminals No.2 and No. 3 with the throttle fully closed. (Middle and right hand pins when looking from the terminal side of the male terminals)

Is there approx. 4.5K ohm?

YES -- go to step 11

No -- Replace the throttle body

11. Reconnect the TP sensor connector.

12. Turn the ignition switch ON (II).

13. Measure voltage between PCM connector terminals C18 and C27. (Manual shows PCM connector C -- 31 pin connector.)

Is there approx. 0.5V when the throttle is fully closed and approx. 4.5V when the throttle is fully opened?

YES -- Substitute a know-good PCM and recheck (see page 11-5). If voltage is normal, replace the original PCM

NO --Repair short or open in the wire between the PCM (C27) and the TP sensor

14. Measure voltage between PCM connector terminals C18 and C28. (PCM connector C 31-pins)

Is there approx 5V?

YES -- Repair open in the wire between the PCM (C28) and the TP sensor.

NO -- Substitute a known-good PCM and recheck (see page 11-5). If voltage is normal, replace the original PCM.

OH -- this is way too long… –

A cheapo DVM will help you measure resistance and voltage. However, reading the “scan tool” portion would require a better scan tool than the one I’ve got that just shows codes. See Scalbert’s posts.

Perhaps you can divine what’s going on by doing “some” of the tests…

EricL

And, it is probably the TP postion sensor... but, I can't be sure.

See the post above. If you had a crudy connection, etc, you could have same problems as listed in the service manual...

-- my opinions YMMV --

And here is a link with someone with a different vehicle having a P0122 error.

http://www.cartrackers.com/Forums/li...star/1153.html

TopGum

Thanks Eric. They don't call you the "Mega Moderator" for nothing! I'll likely do a dealer repair on this but now I will REALLY know what I'm talkin' about.

Ant7701

If ur under warranty go to the dealer and u should get a whole new throttle body...because the tp sensor itself is non-removable.

TopGum

Wierd. The CEL went out. Car idles better but still a lot of hesitation and mild jerking on the freeway. All this talk about throttle bodies is making me think KingMotorSports Would this still be a throttle postion sensor problem? Could it be a short or something with the SC? Thanks, Steve