1982 Corvette Getting Code 22

[jdp6000]

I have an 82 Corvette with plenty of problems. I just replaced the TPS. I adjusted it to .525. I get code 22. Further testing is required. I have the 1982 Shop manual but am having problems understanding what it is I have to do when testing code 22....section 6 in the book.

Does anyone out there have the 1982 shop manual??? In the instruction is states, "disconnect TPS and jumper CKTS 416 and 452". What does this mean??? I get the part about disconnecting the TPS...but what are they talking about when they say "jumper CKTS 416 and 452??

Any help would be appreciated.

BYW what does the term "CKTS" represent???

Jim

 

[geekinavette]

Circuits

 

[AdvancedAutoCC]

I have an 82 Corvette with plenty of problems. I just replaced the TPS. I adjusted it to .525. I get code 22. Further testing is required. I have the 1982 Shop manual but am having problems understanding what it is I have to do when testing code 22....section 6 in the book.

Does anyone out there have the 1982 shop manual??? In the instruction is states, "disconnect TPS and jumper CKTS 416 and 452". What does this mean??? I get the part about disconnecting the TPS...but what are they talking about when they say "jumper CKTS 416 and 452??

Any help would be appreciated.

BYW what does the term "CKTS" represent???

Jim

CKTS is GMspeak for circuits.

Disconnect the connector from the TPS. On the harness side connector (the one the wires are attached to), run a jumper wire from the BLACK wire to the GRAY wire (Black wire is ckt 452, the gray wire is ckt 416), and continue the diagnostic process. TPS voltage at idle should be .56 volts, so your setting of .52 is out of range, but not enough to flag a code I don't think. TPS WOT (Wide Open Throttle) voltage should be 5 volts (or reasonably close to it).
Remember, your CCC system was state of the art in 1982, but is woefully primitive in comparison to todays OBD systems. Hope this helps you!

 

[jdp6000]

CKTS is GMspeak for circuits.

Disconnect the connector from the TPS. On the harness side connector (the one the wires are attached to), run a jumper wire from the BLACK wire to the GRAY wire (Black wire is ckt 452, the gray wire is ckt 416), and continue the diagnostic process. TPS voltage at idle should be .56 volts, so your setting of .52 is out of range, but not enough to flag a code I don't think. TPS WOT (Wide Open Throttle) voltage should be 5 volts (or reasonably close to it).
Remember, your CCC system was state of the art in 1982, but is woefully primitive in comparison to todays OBD systems. Hope this helps you!

Okay...so I did it wrong. I guess the principle here is to see if the ecm is sending and receiving the correct signal. This test has nothing to do with connecting to the TPS. I'll do this again.

Question though...once I have done the above test...let say I get code 22. The shop manual says to remove jumper 416 and 417 then check the voltage between pin A and C. Does this mean I leave 452 connected to the TPS.

Jim

 

[AdvancedAutoCC]

No, you do not have to leave 452 connected. The step that asks you to check the voltage between A and C is verifying the 5 volt reference signal that the ECM is sending out. WARNING!!! use a high-impedence voltmeter only! DO NOT use an older style meter with a needle that "sweeps". The low impedence meters will allow too much current to flow through the circuit and will damage the ECM. The best overall DVOM to have in your toolbox is a Fluke 87 (it was a GM approved essential tool in fact). You want a DVOM (digital volt/ohm meter) with 10 meg-ohm impedence. Most modern DVOMs are high-impedence, but check to be sure. Under NO circumstances should you use a test light to verify CCC voltages unless specifically instructed to do so by the manual. Good luck!

 

[jdp6000]

No, you do not have to leave 452 connected. The step that asks you to check the voltage between A and C is verifying the 5 volt reference signal that the ECM is sending out. WARNING!!! use a high-impedence voltmeter only! DO NOT use an older style meter with a needle that "sweeps". The low impedence meters will allow too much current to flow through the circuit and will damage the ECM. The best overall DVOM to have in your toolbox is a Fluke 87 (it was a GM approved essential tool in fact). You want a DVOM (digital volt/ohm meter) with 10 meg-ohm impedence. Most modern DVOMs are high-impedence, but check to be sure. Under NO circumstances should you use a test light to verify CCC voltages unless specifically instructed to do so by the manual. Good luck!

I have a good digital meter. Last time I checked pin A to C I got 5.2 volts.

Thanks
Jim