02 SL2 Injectors not pulsing

[OldNuc]

Why when it can be checked directly at he bulkhead connector on the 02 DOHC? Are you aware of the cranking amplitude of the signal and the waveform? Do you realize that no DVM correctly displays the correct value for that waveform and the result must be interpreted after knowing exactly what the meter responds to and is calibrated to display? Most people who are doing this use an oscilloscope, it is much simpler.

Presence or absence of the CKP signal can be demonstrated directly with about 30 seconds of effort if the OP has some outside help.

If the cranking RPM does not reach a minimum of 250RPM the CKP amplitude will not be adequate to be recognized by the ECU and imitate spark, fuel pump, and injector pulses.

Have any of these 3 items been verified to be present when cranking?

Is the battery fully charged? Have the plugs been removed and cylinders oiled or are the pistons running dry?

[OldNuc]

A clue is the zero RPM when cranking on live data. The other clue is the service wrench. If the tach circuit is open you set a service wrench.

Pull all the plug wires from the coils and remove all plugs. Fully charge battery and crank engine while checking for spark at the coils. IF no spark then check power to the ICM by sticking a pin into the +12v wire at pin A, pink wire and pin B, black/white wire at the ICM. Do not disconnect the connector just read the voltage between these 2 pins with the key in the run position. Pin D is the position pulse out that ends up being the tach signal. The minimum indicated cranking RPM is 60RPM and the nominal with the plugs out is 250 or so. Cranking at 250 should generate a CKP voltage high enough to be detectable at both ends of the pin D wire to the ECU.

The ECU has to know the engine is actually cranking over so that process is initiated by the CKP signal to the ECU and by all symptoms that is not happening. There is nothing in the ICM circuitry that will prevent the FP and INJ from operating when cranking.

A PCM swap requires a match on the engine type, transmission type, cruise, and ABS all else is in the BCM. Any good 01-02 should be adequate. The 30 minute relearn process is critical to get it all running again.

[RB56]

Having to work late this evening, so no work on the car. Hopefully tomorrow evening can spend a little time on it.

To clarify:
1. The CKP sensor circuit was checked at the PCM connector and gave a reading of about 930 ohms.
2. The ICM pin A has 12V when key is on.
3. I don't have an oscilloscope.
4. Battery is fully charged and reads 12.8+volts. (I've been keeping a trickle charger on it to make sure the battery charge stays up.)
5. Pulling the plug wires off the coil packs and trying to start did not produce any arcing.
6. Plugs are dry.

I will pull all plugs and pull the wires off the coil packs to see if I get arcing with the faster spinning engine.

Also, see if I can tell if ICM pin D has anything I can read.

Thanks for the heads-up on used PCM selection matching the transmission. I might not have even looked at that when selecting one.

Again, thanks everyone for the help so far.

[OldNuc]

Remove plugs and put a squirt of engine oil in each cylinder so they are not dry. The service wrench code is a question that begs for an answer. You should read a low level AC voltage on D to ground.

This is the security relearn procedure.
http://www.saturnfans.com/forums/sho...17&postcount=4

It might be of value to trip security and then run through the reset procedure above.

[RB56]

Haven't made any troubleshooting progress in a few days. I had to work out of town the latter part of last week. The only thing I was able to do was pull a PCM at U-Pull-IT.
Unless it rains this evening, I plan to do the following:
1. Test pin D on the ignition control module.
2. Pull all plugs, put some oil in the cylinders, and spin her over.
3. Replace the PCM and run through the relearn sequence.

[RB56]

Tested Ignition control pin D and had voltage, so I decided to swap PCMs.

Got PCM from U Pull It (02 SL1 Automatic) and put it in. When through relearn, and the car started right up.

Drove down the street to test and there is a problem with transmission. In low gear, seems to be fine, but in drive, once it gets up to about 30 MPH, the transmission seems to disengage and the RPMs shoot up. I took my foot off the gas and when the RPMs came back down the transmission engaged again.

I assume the used PCM I got, was not exactly the same as the old one.

I guess I should put the original one back in, do the relearn and try it. If that doesn't work I'll have to look for another PCM to try.

[OldNuc]

The trans must be learned. Your old PCM is no good! Follow this procedure. Put selector in drive and leave it there. Now drive at no more than 1/2 throttle until trans is in forth gear and then allow the transmission to step through each gear as you brake to a complete stop. Repeat until smooth. Once you have a smooth shifting trans then go to a highway and get to a 55-65mph cruising speed and force a down shift by applying gas. Once it shifts back to 4th allow speed to drop to 35-40 and repeat the down shift 2 or 3 times until reacting as expected.

[fdryer]

According to service manual procedures, new pcm's are programmed and calibrated by GM using their Tech II scantool. No mention of using donor pcm's so this may present additional issues. Replacing a pcm with a new one also states a crankshaft relearn procedure but this requires GM's scantool, a tool no one has for home use except for a few.

The service manual states; Important

Following the PCM reprogramming, the PCM will have to learn the crankshaft notch variation for misfire diagnostics.

Perform the Crankshaft Position Variation Learn Procedure. Refer to DTC P1336 . This procedure will flash the SERVICE telltale.

The DTC 1336 is below. Be aware that this procedure describes a newly programmed pcm requiring a crank relearn using GM's scantool and not anyone's personal reader or scantool that doesn't have programing capabilities. The xmission shift points may be due to either time needed for the pcm to learn how to shift or the lack of a crank relearn is preventing correct xmission shifts. Most members using a donor pcm have almost zero issues.

[OldNuc]

^^^Many gen-3 PCMs and BCMs have been successfully swapped out without recourse to dealer services or crank relearn. If you have a failed gen-3 PCM or BCM you have nothing to lose by trying a DIY replacement.

[RB56]

Tried the trans learning described by OldNuc but could not complete. Here is what happens:
1. Put the car in drive and start acceleration.
2. The transmission very quickly shifts through all (4) gears then goes into neutral by the time I reach 20-25 mph.
3. After that happens, when the rpms come down it shifts into low and stays there (won't try to shift again).
4. I tried coming to a complete stop, but it still stayed in low.
5. After that I tried stopping and turning the key off. Then when I started it again, put it in drive, and accelerated, it quickly shifted though all (4) gears and then into neutral.

Tried this several time but there was not any change.

[OldNuc]

Did you set any codes? If not then the PCM TCU section is shot. Remember a 00-02 PCM from a DOHC with auto trans and cruise and ABS must also match, either with or without.

[RB56]

After driving a second time, the OBDII finally received 3 error codes:
P0732, P0733, P0734.

The shifting never got any better.

I did try giving it more than 50% throttle and it does wait longer between shifts, but still goes into neutral by itself after shifting though 2, 3, and 4.

I called my U-Pull-It, but they don't have any more automatics, so I'm stuck until I can find an appropriate PCM.

[OldNuc]

Based on the results of others I would suspect the PCM TCU section first. The Gen-3 powertrain controls seem to have a high failure rate compared to the earlier cars.

[billr]

With three "wrong ratio" codes, I would be checking line-pressure with a gauge before attacking a PCM.

[RB56]

I bought another PCM on the internet. This one is the exact match part number wise.

While I am waiting for it to come in...
Were is the transmission line pressure test port, and what are the acceptable pressures for different gears and throttle percents?

[billr]

You read line pressure at the port the trans temperature sensor screws into; it is 1/8" NPT, so finding adapter fittings is easy. I would use a "T" so that the temp sensor can still be in place. It may not read exactly as intended, but will be close enough so codes and bad shifting from having it completely removed can be avoided.

I don't know that there are specified pressures for each gear/rpm/load combination, but there is a simplified LP test that may show an obvious problem. Roughly speaking, at idle and normal (trans) temperature, pressure should be in the 60-70 psi range. Then, you remove the fuse for the LP solenoid and pressure should rise to about 250 psi. The exact pressure ranges vary with the year, so do a search here for the procedure if "Chazberry" doesn't post a link...

Oops, I forgot my usual sermon: with OBD2 you can easily get live-data and eliminate a lot of guessing here (but not for the LP, no sensor for that!)

[OldNuc]

Originally Posted by RB56

I bought another PCM on the internet. This one is the exact match part number wise.

While I am waiting for it to come in...
Were is the transmission line pressure test port, and what are the acceptable pressures for different gears and throttle percents?

There is a part number and then a firmware number, neither tell you exactly what equipment was on the car. There are only 2 gen-3 PCM units, 1 for the manual transmission and a 2nd for the automatic. Either may be programed for the SOHC or DOHC engine and for the applicable transmission. The transmission firmware is either economy or performance specific and not interchangeable between transmissions.
Going all the way back to the first post that started this thread there is no mention of transmission issues and now all of a sudden you are getting incorrect ratio codes. I do not buy this is a transmission problem without a lot more info.

[billr]

Agreed, we are "wandering in the weeds" here, and it doesn't seem likely the problem is with the trans; but checking LP and live-data stuff is so easy to do with OBD2, I like to make those basic checks right away when trans codes pop up.

[OldNuc]

It is OK to check the pump output but the vast majority do not have the equipment to run that test without help and definitely not if alone.

This gen-3 PCM issue causes a great deal of confusion as most yards do not record the info you need to see and generally assessable VIN info sites now want real money up front.

Then you add in the rapidly increasing hardware failure rate of these PCMs.

[RB56]

Received the PCM and put it in. It starts up and engine sounds great, just like with the first replacement PCM. However the transmission shifting is still doing the same thing...quickly shifting through the gears and then into neutral.

I tried putting the original PCM back in but it must really be dead. The [Security] light did not blink or stay on and car would not attempt to start even though the starter turns over.

Is it probable that another PCM is what I need, or should I start looking at the transmission?