OBD codes

[jgranthevagrant]

Ok. Checked the FAQs and numerous sites. Truck is a 1990 Extended cab. 4 x 4. Has 320 000 kilometres on it. Started hesitating and running rough in all gears about 3 days ago.

- changed the fuel filter.
- checked timing.
- plugs, cap and rotor are new.
- air filter new.
- exhaust is new from manifold back
- no coolant or abnormal oil loss.
- Aircared in July. (emissions test)

I ran the OBD codes. I get 21 (O2 sensor) and 51 (switch signal). I have no idea what the switch signal is.

Truck is in Canada. I'm not sure if the codes were the same for Canada as California or the rest of U.S.

I will probably change the O2 sensor tomorrow.

Any help would be great. This site is excellent and informative.

 

[snobdds]

Since your in canada...what engine are we dealing with here, the 22re or the 3vze?

I assume it's a gasser since you replaced the spark plugs...

 

[jgranthevagrant]

yeah. 22re. Gas.

Just replaced the O2 sensor, but the wiring harness was missing. PO had it shorting on the exhaust, so cut it off. Garage reinstalled and spliced the wiring, but no guarantee it was correct. I tried two different wiring configurations. No difference. Cleared OBD codes. Came back with 21 and 51 each time. I hope the codes are the same for the Canada model as for California. I only have a list of California codes and what I found on the crawler page.

 

[snobdds]

Code 21 refers to the heater circuit of the O2 sensor.

If the wires melted together and shorted power directly to the ECU circuit for the O2 sensor heater it may have fried the driver in the ECU for the O2 sensor heater.

 

[jgranthevagrant]

Thanks. I will check into that. Probably a couple of days before I can get to it.

 

[jgranthevagrant]

Ok. O2 sensor replaced and rewired. Running ok. No CEL. But timing doesn't change when T to E1 jumpered. I will look into the TPS and the ECU over the next week or so.

 

[pappy]

Ok. O2 sensor replaced and rewired. Running ok. No CEL. But timing doesn't change when T to E1 jumpered. I will look into the TPS and the ECU over the next week or so.

Could be the ecu is not getting an IDL signal from the tps .