Neon L4-2.0L DOHC (1996)
Powertrain Control Module (PCM) cavity 36. The MAP sensor puts out a low voltage signal (0.5 to 1.8 volts) at idle when the manifold vacuum is
high, and a higher voltage signal (3.9 to 4.8 volts) at deep throttle when the manifold vacuum is low. The MAP receives a 5-volt supply from PCM
cavity 61; voltage may vary from 4.8 to 5.1 volts. The sensor ground is provided by PCM cavity 43.
POSSIBLE CAUSES:
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Restricted or leaking vacuum/pressure to MAP sensor
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Ice in sensor or passage
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Failed sensor
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Failed PCM
TPS Voltage Does Not Agree With MAP
Name of Code:
TPS Voltage Does Not Agree with MAP
When Monitored:
With the engine running and no MAP sensor or TP sensor trouble codes.
Set Condition:
The powertrain control module (PCM) performs two separate tests on the TP sensor: the high voltage test and the low voltage test. The high
voltage test is performed when the engine speed is very low and manifold vacuum is very high; these conditions indicate that the throttle plate must
be nearly closed, in which case the TP sensor signal voltage output must be low. The low voltage test is performed when the engine speed is above
25 mph and manifold vacuum is low; these conditions indicate that the throttle plate is open, in which case the TP sensor signal must be high. If
the proper TP sensor voltage is not present when the two conditions are met, the code will set after 4 continuous seconds.
Theory of Operation:
The TP sensor contains a potentiometer that is operated by the throttle blade shaft. As a throttle plate rotates, the TP sensor provides a variable 0
to 5-volt signal to PCM. The voltage is directly proportional to throttle angle. When the throttle plate is at rest, the voltage is low. When the
throttle is fully open, the voltage is high. With this signal, the PCM can determine precise throttle position under all operating conditions. The TP
sensor receives a 5-volt supply from the PCM. The sensor ground is provided by the PCM.
Possible Causes:
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Failed powertrain control module
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Connector wires
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TP sensor failure
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Vehicle speed
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Mechanical failure
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MAP sensor
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Connector terminals
