Have a Car Question? Ask a Mechanic Online.
No problem...Here is the diagnostic for code 33 on your truck:
Circuit Description: The Manifold Absolute Pressure (MAP) sensor responds to changes in manifold pressure (vacuum). The ECM receives this information as a signal voltage that will vary from about 1-1.5 volts at closed throttle (idle) to 4-4.6 volts at Wide Open Throttle (WOT) (low vacuum).If the MAP sensor fails, the ECM will substitute a fixed MAP value and use the Throttle Position Sensor (TPS) to control fuel delivery.Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.
Diagnostic Aids: With the ignition "ON" and the engine stopped, the manifold pressure is equal to atmospheric pressure and the signal voltage will be high. This information is used by the ECM as an indication of vehicle altitude. Comparison of this reading with a known good vehicle with the same sensor is a good way to check accuracy of a "suspect" sensor. Readings should be the same +/- .4 volt.A Code 33 will result if CKT 455/469 is open or if CKT 432 is shorted to voltage or to CKT 416.If Code 33 is intermittent, see Intermittents. See: Symptom Related Diagnostic Procedures\Intermittent Condition
They get refwerence power from the same wire..It is the TPS, Coolant temp sensor and MAP on this reference signal voltage..That is the only way they are connected together.
High voltage means low vacuum, if the computer thinks the throttle is open farther than it really is, then it could POSSIBLY cause this problem, but it would USUALLY set another code for the TPS. Possible, but not the most likely cause.
So..Here are the instructions for testing the TPS:
Fig. 2: Using a DVOM, backprobe terminals A and B of the TPS sensor to check for proper reference voltage Fig. 3: Using the DVOM, backprobe terminals C and B of the TPS sensor, open and close the throttle and make sure the voltage changes smoothly Fig. 4: Throttle Position Sensor (TPS) wiring diagram
2003 Jetta left rear window blue plastic part of the