Vehicle Speed Sensor
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From: lemoore ca
Vehicle Speed Sensor
I forget what the code is but it is for the vehicle speed sensor signal. It is causing my speedometer, odometer, and fuel mileage not to work but my cruise control speed still shows up on the dic. I replaced the sensor no joy anyone have a wiring diagram for the sensor and any ideas?
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From: Murphy TX
Cruise-In II Veteran
Is it the PCM output signal code? You could be losing either the input to the PCM or the output of the PCM. I don't think it'll pop the output code if the input is missing, though I'm not sure. I don't recall a DTC that monitors the inputs, though that would be helpful here.
In any case, if you can't easily identify an obvious problem in the signal path, you need to verify the PCM is seeing the input signal. There are two input lines. You might be able to peek at both at the connector from the tranny to engine harness in the engine compartment. However...
The fact that you see speed via cruise is surprising to me but also suggests that the PCM has input. I am speculating that the TAC module and PCM communicate target cruise speed (in some form) via the serial data line between the PCM and TAC. If that's the case, the facts that you see vehicle speed on the DIC and that cruise works validate that you have VSS input to the PCM. If that's in fact the case you need to be looking at the output side. Unless it's something simple like a connector dislodged or damaged circuit, I'd be leaning toward a PCM fault. Are all the rest of your gauges operating properly?
In any case, if you can't easily identify an obvious problem in the signal path, you need to verify the PCM is seeing the input signal. There are two input lines. You might be able to peek at both at the connector from the tranny to engine harness in the engine compartment. However...
The fact that you see speed via cruise is surprising to me but also suggests that the PCM has input. I am speculating that the TAC module and PCM communicate target cruise speed (in some form) via the serial data line between the PCM and TAC. If that's the case, the facts that you see vehicle speed on the DIC and that cruise works validate that you have VSS input to the PCM. If that's in fact the case you need to be looking at the output side. Unless it's something simple like a connector dislodged or damaged circuit, I'd be leaning toward a PCM fault. Are all the rest of your gauges operating properly?
Last edited by ToplessTexan; Apr 13, 2006 at 09:15 AM.
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From: Murphy TX
Cruise-In II Veteran
Based on that an the cruise thing I'm thinking a PCM fault. The test is monitoring the relationship between inputs and output within the PCM and failing. The fault isolation tree for that DTC steps you through some stuff to verify you have valid input to the PCM. If you get that far and still have the code and no joy at the cluster, it says to replace the PCM. 
One other thought is that you shouldn't necessarily trust this analysis if the status of the electrical system is flaky, say shaky ground and so forth. Any other interesting things start happening at around the same time?
One other thought is that you shouldn't necessarily trust this analysis if the status of the electrical system is flaky, say shaky ground and so forth. Any other interesting things start happening at around the same time?
Last edited by ToplessTexan; Apr 13, 2006 at 09:10 AM.
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From: Murphy TX
Cruise-In II Veteran
That's the processor that controls the real time dampening (RTD) function. It also sees the vehicle speed output provided by the PCM.
DTC is the TLA for data trouble code. The service manuals typically have a fault isolation procedure to follow for DTCs. Following them blindly can lead to a parts replacement fiesta. Often times the presence of several trouble codes can be an indicator of a more global, and perhaps much simpler, problem.
DTC is the TLA for data trouble code. The service manuals typically have a fault isolation procedure to follow for DTCs. Following them blindly can lead to a parts replacement fiesta. Often times the presence of several trouble codes can be an indicator of a more global, and perhaps much simpler, problem.
Last edited by ToplessTexan; Apr 13, 2006 at 09:37 AM.