Anyone have a list of the ECM codes for an 84

DTC codes for 1984:

12 - System normal/communications ok/end of diagnostics
13 - O2 Sensor
14 - Coolant Sensor low voltage
15 - Coolant Sensor high voltage
21 - Throttle Position Sensor high voltage
22 - Throttle Position Sensor low voltage
24 - Vehicle Speed Sensor
33 - MAP Sensor low voltage
34 - MAP Sensor high voltage
42 - Electronic Spark Control
44 - Lean Exhaust
45 - Rich Exhaust
51 - PROM
55 - ECM

Report back what you find, and we can start diagnosing!

Came up with code 21. Throttle postion sensor. Any idea where this is located. Will check wiring first then replace unless you have some other things I could check.

the TPS is on the throttle body somewhere... I just don't know where.

This 84 is my son's car but I have an 82. I've got the gm shop manual for mine (both cars have the same engines technically)and found the throttle position sensor, it's on the rear throttle body. I read a blog that says you may be able to do adjustments but I can't see how and the manual does'nt mention anything. The wiring and connector look good so guess I'll have to go shell out some dinero for a new one, hope it fixes the check engine light will let you know. Thanks again for the codes!

The blog may be right. Many times, we owners find ways around things that the mfg never considered... or don't want us to know.

Case in point are the procedures for doing the heater core. It's an absolute nightmare, but done the easy way... saves half the labour.

Found this online - apparently it's from autozone's free online database, but I am not signed up for that:

Any time the TPS is removed, it must be readjusted according to the following procedure.

Throttle Position Sensor (TPS) See Figure 9

http://repairguide.autozone.com/znetr ... dium/0900c152800835ee.gif

Fig. Fig. 9: Throttle Position Sensor (TPS) adjustment

An accurate digital voltmeter is needed to perform this adjustment.

Remove the TPS attaching screws and apply thread locking compound to the screws. Reinstall the screws loosely.

Install three jumper wires between the TPS and the TPS wiring terminal connections, as shown in the accompanying illustration.

Turn the ignition ON and measure the voltage between the A and B terminals of the TPS. Rotate the TPS to obtain a voltmeter reading of .525 .075 volts. Tighten the screws.

Turn the ignition OFF, remove the jumpers, and connect the TPS wiring to the TPS.

Thanks for the info. Installed the new tps, it came with instructions on how to adjust it although the values were a little different. But what a DIFFERENCE!! Took care of the check engine lite but mainly the idle problem, smooth!!

awesome!!!