Soon after I start driving I'm getting a "Service ASR" light on my '92 LT1. It resets when the engine is shut off, but comes on again with the slightest acceleration. I checked the codes and I'm getting a module 9 H65 each time the light comes on. Sometimes I also get a module 1 H72 and H74. Are these related? "Check Engine" doesn't come on. Can anyone give me a place to start trouble shooting? Thanks.

 

The H65 is an ABS adjuster assembly fault. You'll need pages 5E1-94thru97 for the trouble shooting charts. The H72 and H74 are LCD dimming circuit error codes. Does your car have an aftermarket radio? :steering:

 

Thanks for the reply...

Yes I do have an aftermarket radio. Are those faults I can correct, or is it something I'll have to live with?

Concerning the H65...What's an ABS adjuster assembly? I'm thinking maybe it's the electric motor assembly under the "ASR" housing? What manual are you refering to about the trouble shooting charts?

 

Alright Bruce, since you're in the aviation business too, here you go. The long version for the Dimming Circuit codes --- http://www.corvetteforum.net/c4/dave8476/index4.shtml The short version --- . Buy (2) 1 kilo-ohm 1/2 Watt resistors. [Radio Shack part # 271-023. They sell them as a 2-pack for 29 cents.]
2. Disconnect the negative battery cable.
3. Remove the receiver.
4. Connect one end of both resistors to ignition power. (Yellow wire in the car.)
5. Connect the other end of one resistor to the purple/white wire in the car.
6. Connect the other end of the second resistor to the grey/black wire in the car.
7. Cover all connections and completely cover the resistors.
8. Reconnect the negative battery cable. The manual I was referring too is the Helms. If you plan on keeping your car for awhile you'll need to pick a set up. It comes in a two volume set. The adjuster assembly is the unit with the black ASR cover under the hood. Here's what it says The Adjuster Assembly circuit provides both power and ground to the Adjuster Assembly to help controll engine torque during an ASR event. Code 65 will set if CKT 1685 or CKT 1686 are shorted to ground, shorted to B+, shorted to each other, or both open at the same time. The ASR system will be disabled for the remainder of the ignition cycle and the "SERVICE ASR'' lamp will illuminate. Try clearing the codes and see if that one remains. By the way, who do you fly for? I'm a controller at ZME. :steering:

 

Thanks...that's great information! I'm going to get right on the resistor installation.

As for the code 65...I've reset it a few times, but it continually returns. I've checked all the connections leading to the adjuster assembly and it all looks OK. I'll have to pick up a copy of those service manuals and trouble shoot some more.

I work for Southwest. I fly out of Houston and go through Memphis Center alot...you guys do good work there. :cheers:

Bruce

 

It seems Helms has dropped the price somewhat. http://www.helminc.com/helm/product2...3UJ41L6PH25116 When you're in the vicinty of BNA ask for Ransome. :steering:

 

Thanks again...I'll do that.