I am using a conventional TPS sensor with my Megasquirt setup but am now fitting a ZF4HP22EH auto transmission. It is from a BMW 535 and uses an electronic controller to control the shifts. It also requires an input from the TPS.
Question is can I just use the one TPS and let Megasquirt provide the ref voltage and just daisychain the TPS sig back from the Megasquirt to the tranny controller or will I have to use a separate TPS for each controller.
Anyone faced this issue?
-Thanks in advance for any help Alan
Using single TPS for Megasquirt and Tranny ECU
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
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alan_thomas
- MegaSquirt Newbie
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Bernard Fife
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Re: Using single TPS for Megasquirt and Tranny ECU
Alan,
Yes, as long as the tranny ecu is high impedance (doesn't draw much current) you can share the TPS signal. The tranny ecu is very likely high impedance (most controllers are set up this way).
Where people get into trouble is trying to share things like coolant sensors, because those use the resistance in the sensor to form a voltage divider, and this doesn't work so well if you have two voltage sources.
Lance.
Yes, as long as the tranny ecu is high impedance (doesn't draw much current) you can share the TPS signal. The tranny ecu is very likely high impedance (most controllers are set up this way).
Where people get into trouble is trying to share things like coolant sensors, because those use the resistance in the sensor to form a voltage divider, and this doesn't work so well if you have two voltage sources.
Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it.” - George Bernard Shaw
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alan_thomas
- MegaSquirt Newbie
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Re: Using single TPS for Megasquirt and Tranny ECU
Thanks Lance, I'll give it a try. Unlike to cause any damage to either then? - Alan