Moates vs. Red Devil River cable for 87 C4
Thread Starter
Racer
Joined: Apr 2016
Posts: 494
Likes: 93
From: Bucks County PA
Moates vs. Red Devil River cable for 87 C4
I've read over quite a number of threads here and on the Thirdgen site as well, but wanted to ask. I seem to remember a post or 2 from owners of 1987 L98's and the 165 ECM (I'm thinking in a Thirdgen car) having some issues with the Red Devil River Cable and others chiming in that they had some issues as well They suggested the Moates cable and ALDU1 (That's what I was leaning toward anyway).
For those that are using both these, Especially for the 1987 if there could be issues, can you give me opinions on which is "preferred" ??? or the main differences between them?? I'm not sure if the 87 C4 uses the same "165" ECM and it's been years since I've done anything with OBD-1 cars, so I'm really out of the loop on them. I do still have the 83 Hurst/ Olds and the last C4 I have is the '87 (pulled out of storage after decades), but everything else I have is pre-1979 or much newer OBD-II etc. Now that the Grand Nationals are gone, the 83 H/O are the only OBD1 cars I have left.
In another post the forum helped me narrow down my choices but I never got around to ordering. Just wanted to get a comparison so I can decide and order Any opinions would be appreciated
For those that are using both these, Especially for the 1987 if there could be issues, can you give me opinions on which is "preferred" ??? or the main differences between them?? I'm not sure if the 87 C4 uses the same "165" ECM and it's been years since I've done anything with OBD-1 cars, so I'm really out of the loop on them. I do still have the 83 Hurst/ Olds and the last C4 I have is the '87 (pulled out of storage after decades), but everything else I have is pre-1979 or much newer OBD-II etc. Now that the Grand Nationals are gone, the 83 H/O are the only OBD1 cars I have left.
In another post the forum helped me narrow down my choices but I never got around to ordering. Just wanted to get a comparison so I can decide and order Any opinions would be appreciated
Last edited by 76C3forme; Jan 22, 2022 at 02:03 PM.
Thread Starter
Racer
Joined: Apr 2016
Posts: 494
Likes: 93
From: Bucks County PA
Thanks
Hey Thanks.
I found that thread about the 165 ECM and issues with the Red Devil River cable.. It was on an F Body (1987 L-98 with the 165 ECM). I Wonder if it could have been an "isolated thing". I don't seem to see anything negative other than that particular post. (still leaning toward the Moates though).
Thirdgen Link 165 ECM
I found that thread about the 165 ECM and issues with the Red Devil River cable.. It was on an F Body (1987 L-98 with the 165 ECM). I Wonder if it could have been an "isolated thing". I don't seem to see anything negative other than that particular post. (still leaning toward the Moates though).
Thirdgen Link 165 ECM
Last edited by 76C3forme; Jan 22, 2022 at 10:40 PM.
Melting Slicks
Joined: Mar 2001
Posts: 2,149
Likes: 303
From: Timra, Sweden
What is special with the 165 ECM (1986-1989) is that it supports both the older "one way" 160 baud and the newer "two way" 8192 baud ALDL interface.
Using 8192 baud you get more data and MUCH higher update frequencey.
The reson for keeping 160 baud is that the same data output is used for MPG-data to the digital dash and that was kept identical as in the earlier 1984-1985 Corvettes. When the new interior arrived in 1990 the 160 baud interface was dropped.
( When you connect a scanner, 160 or 8192 baud, you loose MPG-data updates on the dash )
Using 8192 baud you get more data and MUCH higher update frequencey.
The reson for keeping 160 baud is that the same data output is used for MPG-data to the digital dash and that was kept identical as in the earlier 1984-1985 Corvettes. When the new interior arrived in 1990 the 160 baud interface was dropped.
( When you connect a scanner, 160 or 8192 baud, you loose MPG-data updates on the dash )
Race Director
Joined: Sep 2003
Posts: 16,837
Likes: 338
From: Database Error Indiana
Hey Thanks.
I found that thread about the 165 ECM and issues with the Red Devil River cable.. It was on an F Body (1987 L-98 with the 165 ECM). I Wonder if it could have been an "isolated thing". I don't seem to see anything negative other than that particular post. (still leaning toward the Moates though).
Thirdgen Link 165 ECM
I found that thread about the 165 ECM and issues with the Red Devil River cable.. It was on an F Body (1987 L-98 with the 165 ECM). I Wonder if it could have been an "isolated thing". I don't seem to see anything negative other than that particular post. (still leaning toward the Moates though).
Thirdgen Link 165 ECM
Maybe I was just lucky. I will say that everything I got from Moates was top quality. That may be reason enough to by from him.
Thread Starter
Racer
Joined: Apr 2016
Posts: 494
Likes: 93
From: Bucks County PA
What is special with the 165 ECM (1986-1989) is that it supports both the older "one way" 160 baud and the newer "two way" 8192 baud ALDL interface.
Using 8192 baud you get more data and MUCH higher update frequencey.
The reson for keeping 160 baud is that the same data output is used for MPG-data to the digital dash
Using 8192 baud you get more data and MUCH higher update frequencey.
The reson for keeping 160 baud is that the same data output is used for MPG-data to the digital dash
Thread Starter
Racer
Joined: Apr 2016
Posts: 494
Likes: 93
From: Bucks County PA
I kind of think the same way. I did actually reach out with a few questions on the Red Devil River cable on several occasions but didn't get a reply back. I've heard others mention the same thing I think I'll most likely order the moates and play it safe.
Melting Slicks
Joined: Mar 2001
Posts: 2,149
Likes: 303
From: Timra, Sweden
The MPG-data package is 5 bytes and is repeated at about 4 times each second.
With a 10k resistor between A and B on the ALDL connecor the full 25 byte package is sent and it repeats a bit slower than ones every second.
With the resistor removed the ECU returns to the 5-byte MPG package.
I don't know the details about the 8192 baud but the scanner sends a request to read data, and then the ECU switch over to 8192 baud.
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Thread Starter
Racer
Joined: Apr 2016
Posts: 494
Likes: 93
From: Bucks County PA
The MPG-data just halts as the dash does not receive any new valid MPG-packages. Then it resumes when packages are read again.
The MPG-data package is 5 bytes and is repeated at about 4 times each second.
With a 10k resistor between A and B on the ALDL connecor the full 25 byte package is sent and it repeats a bit slower than ones every second.
With the resistor removed the ECU returns to the 5-byte MPG package.
I don't know the details about the 8192 baud but the scanner sends a request to read data, and then the ECU switch over to 8192 baud.
The MPG-data package is 5 bytes and is repeated at about 4 times each second.
With a 10k resistor between A and B on the ALDL connecor the full 25 byte package is sent and it repeats a bit slower than ones every second.
With the resistor removed the ECU returns to the 5-byte MPG package.
I don't know the details about the 8192 baud but the scanner sends a request to read data, and then the ECU switch over to 8192 baud.
I'm not that experienced with data logging with the OBD-1 , but I'm curious about it. Mainly I'd like to just get a good "snapshot" when the car is running well so I can compare when / if something goes wrong. Seeing the sensor values etc I think would be a good thing while the car is running correctly..
Melting Slicks
Joined: Mar 2001
Posts: 2,149
Likes: 303
From: Timra, Sweden
As I said, I don't know as much about the 8192 baud as I have never used it myself.
If Moates states that the 10k is needed then it is probably so.
The A-B resistor can have several vaues.
Open - normal operation
10k - ALCL-mode
In this mode the system operating characteristics are modified as follows:
- Closed loop timers are bypassed
- EST (spark) is advanced
- IAC will control engine idle to 1000 RPM +/- 50 RPM
- On some engines, canister purge solenoid will be enabled
- Park/Neutral restrict functions will be disabled
3.9k - Factory test mode
When in this mode, the ECM is operating on the fuel back-up logic and calibrated by the Calpak (back-up chip). The Calpak Part of Mem/Cal is used to control the fuel delivery if the ECM fails. This mode verifies that the back-up feature is OK. The parameters that can be read on a "SCAN" tool in this mode are not of much use for service.
Short - diagnostic mode ( Flash error codes )
Regarding 160 baud data...
On most ECM's you don't need the 10k resistor as the ECU is transmitting data all the time.
10k mode should be used with caution as it changes some things like spark timing.
Specifically on ECU's used in 1984-1989 Corvettes the 10k mode is needed to get scanner data because in normal mode only MPG data is transmitted.
This also apply to for example TPI Camaros as they use the same ECU as the Corvette.
If Moates states that the 10k is needed then it is probably so.
The A-B resistor can have several vaues.
Open - normal operation
10k - ALCL-mode
In this mode the system operating characteristics are modified as follows:
- Closed loop timers are bypassed
- EST (spark) is advanced
- IAC will control engine idle to 1000 RPM +/- 50 RPM
- On some engines, canister purge solenoid will be enabled
- Park/Neutral restrict functions will be disabled
3.9k - Factory test mode
When in this mode, the ECM is operating on the fuel back-up logic and calibrated by the Calpak (back-up chip). The Calpak Part of Mem/Cal is used to control the fuel delivery if the ECM fails. This mode verifies that the back-up feature is OK. The parameters that can be read on a "SCAN" tool in this mode are not of much use for service.
Short - diagnostic mode ( Flash error codes )
Regarding 160 baud data...
On most ECM's you don't need the 10k resistor as the ECU is transmitting data all the time.
10k mode should be used with caution as it changes some things like spark timing.
Specifically on ECU's used in 1984-1989 Corvettes the 10k mode is needed to get scanner data because in normal mode only MPG data is transmitted.
This also apply to for example TPI Camaros as they use the same ECU as the Corvette.
Last edited by JoBy; Jan 25, 2022 at 05:41 PM.