I recently purchased a 92 with the Delteq conversion. The system was working fine most of the drive back to CO but since then my ASR and ABS haven't worked. It doesn't matter if the car is warm or cold, has or hasn't been driven. The ASR/ABS Service and Active lights come on. Sometimes the lights come on when I start the car and other times they come on after I start driving. Sometimes its a bump in the road that causes the lights and oddly enough the stereo to flicker and then reset. I've checked the grounds by the TB and battery and they are fine.

I get the following codes:
CCM H41 - ECM Data Communications Lost
EBCM H62 - Tachometer Data Error
EBCM H71 - EBCM Internal Error

I wonder if the internal tach filter in Delteq module is causing the problems. Has anyone else had these codes and been able to find the problem? I've checked the connectes and didn't find anything loose.

Thanks,
Dave

 

The Delteq has no tach filter -- the tach output from the Delteq is already conditioned without filtering.

In fact, you want the tach output of the Delteq to NOT go through your stock tach filter.
You have to eliminate/bypass your original tach filter for the ABS, ASR, and tach to work properly.

Tom Piper

 

I thought that was the case with the tach filter. Mine is bypassed currently so I was just wondering if the Delteq controller was maybe flaking out.

I got my service manual last night finally and went through the ASR/ABS section. It says that since the H71 code is being set each time teh ASR/ABS goes out that the EBCM needs to be replaced.

Has anyone replaced their EBCM before? Does anyone know a good place to buy one?

Dave

 

I have a Delteq on my '92, and everything works.

Does your tachometer work?

If so, you are receiving the tach signal from the Delteq correctly.


Tom Piper

 

Recheck your by-pass and make shure it didn't come loose. You may want to give Pete at Delteq a call as well he provides exelent customer service. I had the SES light on when I first installed the Delteq but it was the tach filter and you have the recomended by=pass so I would just recheck it to make shure. Take a look at page 14 of the instalation guide (Linked bellow) if you want to make certian. It states 93 only but it is wrong because I had to by-pass it on my 94 as well.


http://www.delteq.com/Manual_r3.pdf

 

As Tom said if your Tach is not working recheck your by-pass

 

Also, A bad TPS sensor can cause your ABS/ASR lights to come on.

 

When I did the LTCC, I had to cut the stock tach filter off in order for the tach to work as well as the ASR.

 

Thanks for the great info! I checked the bypass last night and it looks correct. The tach filter is gone and the wires are secure.

The tach does work correctly. I've never seen it bounce or act odd. I'll check the TPS tonight. I haven't read that section of the service manual yet but I'm sure there is a way to verify the TPS is good or bad.

I did see last night that there is a ground for the TPS by the TB and I'll check it too. It has oil on it because my intake manifold is leaking....that's another project though.

If there's an easy way to check the TPS that's not in the service manual I would love to hear about it.


Dave

 

Since the tach is working, the tach output from the Delteq is OK.

For TPS problems associated with ABS/ASR, keep in mind, the throttle position sensor feeds the "TPS buffer" (square looking device located beside the windshield washer bottle), and the output of the TPS buffer feeds the ABS/ASR. So, if the TPS buffer is defective, the ABS/ASR computer would not get throttle position information but the ECM would.

However, these errors seem to indicate the communications link from the ECM, by way of the CCM, isn't working.
Do you get any CCM error codes?

And, finally, keep in mind, it isn't unusual to have the ECM go bad on vehicles up to and including the '93 model -- the '94 and up ECMs seem to be more immune to problems.


Tom Piper

 

It's good to know the Delteq is working ok. The 3 codes I listed are the only ones that I have seen. I've cleared it numerous times over the past month. Just trying to get it fixed now before winter comes as this is my daily driver and want the ASR to work if I get caught in a snow storm.

Now I have to figure out of the TPS is bad, the TPS Buffer is bad, or the ECM is bad.

I saw in another post that the TPS should be around .54 volts. Is there a way to check the TPS Buffer? I didn't get a chance to verify the TPS is good last night.

Dave

 

My gut-feeling is you have a defective ECM.

The CCM is the master computer and the remaining computers (ECM, ASR/ABS computer, C68 climate control) are slaves.

You are getting a CCM trouble-code telling you the data on the serial-link is down.
You are getting a trouble-code telling you the tachometer information isn't getting to the ASR/ABS computer -- you already know the tach information is getting to the tach, so the Delteq is OK. This probably means the tach information is getting to the ECM.
So, the tach information is getting to the ECM, but the CCM can't get that information from the ECM to pass on to the ASR/ABS computer.

If I am correct, the TPS signal that goes to the TPS buffer and then to the ASR/ABS computer bypasses the CCM and goes directly to the ASR/ABS computer -- so, this eliminates the communications link for it.

From my experience, the pre-'94 ECM is a trouble spot.
So, I think your ECM isn't sending the information to the CCM to pass on to the ASR/ABS.

A decent way to prove this is to disconnect the ABS/ASR and C68 climate control computers.
Doing this, you know you are going to get ABS/ASR errors and C68 errors -- ignore them.
The vehicle will still run without these.
The important thing to look for is the CCM error to see if it is still there.
If it is, there is definitely a communications link problem between the ECM and CCM -- the ABS/ASR and C68 climate control are out of the picture.
If the communications is not there then, you have one of three problems:
1) The serial-link is shorted to ground -- unlikely
2) The CCM is defective -- the CCM hardly ever goes bad
3) The ECM is defective -- the pre-94 ECM is known to go bad frequently.

It's your choice.

Tom Piper

 

Well I checked some things over the weekend and found the following. I checked the voltage coming out of the TPS and it's .6 volts. The voltage coming out of the TPS buffer is .7 volts. This is while the car was idling.

When the car was cold and had sat for 2 days I pulled the codes. The only thing present was ERR on the 9.1 EBCS menu. I drove the car today after resetting the 9.1 module and it gave me the 2 codes:

CCM H41 - ECM Data Communications Lost
EBCM H71 - EBCM Internal Error

I reset the codes this morning and then went for another drive. All ABS/ASR lights lit up a couple of times but no codes were ever set.


Tom,
Does that give you the impression that the ECM is dying?

Thanks for the help,
Dave

 

The trouble-code:
"CCM H41 - ECM Data Communications Lost"
means the CCM has requested data at least three times and never got it from the ECM.

There is a possibility of four computers on the serial-link that the ECM and CCM communicate on:
1) CCM -- the master computer
2) ECM -- the computer that runs the engine
3) ABS/ASR computer
4) C68 climate control

Any of these computers could become defective and short that serial-link to ground and cause a communications failure between the CCM and ECM.
The good thing is the vehicle will still run without the ABS/ASR computer and the C68 climate control computer.
So, to narrow the problem down as much as possible here are my suggestions.
1) Disconnect the battery and disconnect all of four of the computers from the serial-link and measure the serial-link to ground with an accurate ohmmeter. If it is grounded, you've found your problem.
2) Connect only the ECM and CCM to the serial-link and then connect the battery, clear the codes, and see if the same communications trouble-code sets. Make sure you run the vehicle long enough to set the code -- at least to the engine is completely warmed up. If it doesn't, the problem is probably in the ASR/ABS computer or the C68 climate control. If it does set, then either the CCM or the ECM is the problem. Both are needed for the security handshake to start the engine, so you can't narrow it down any further.

Since the ECM is under the hood with the all that heat, if the problem only happens after the engine is warmed up, I would highly suspect the ECM.
The ECM in pre-'94 vehicles is known to be a frequent source of trouble, so between the ECM and CCM, I would think it was the ECM.
But, I can't tell you that for sure.

I don't know any way to narrow the problem down any further without the test fixtures to test them individually like Delco would have done.


Tom Piper