The powertrain control module (PCM) has internal tables that compare manifold absolute pressure (MAP) sensor values with throttle position (TP) sensor values. The MAP sensor is a transducer that varies resistance according to changes in intake manifold pressure (vacuum). The voltage ranges from 1-1.5 volts at idle (low pressure/high vacuum) to 4-4.5 volts at wide open throttle (high pressure/low vacuum). The TP sensor is a potentiometer that varies resistance according to changes in throttle plate position. The voltage ranges from 0.4 (+/-0.2) volts at 0% throttle to 4.7 volts at wide open throttle. DTC P0105 sets when the 2 values are out of the calibrated range from the table values.
DTC P0105 will set if MAP sensor voltage or TP sensor voltage is out of range for 2 seconds when:
• | The engine speed is between 1600-4000 RPM. |
• | The engine speed change is less than 100 RPM, 50 RPM (2000 Model Year). |
• | The exhaust gas recirculation (EGR) command is steady (2000 Model Year). |
• | Idle air control (IAC) change is less than 10 counts (2000 Model Year). |
• | A/C command is unchanged (2000 Model Year). |
• | No 5 volt reference, crankshaft position (CKP), EGR, IAC, MAP, PCM internal fault or TP sensor DTCs have been set. |
DTC P0105 diagnostic runs continuously once the above conditions have been met.
DTC P0105 is a type B DTC.
This DTC will set if either MAP or TP is out of range. To distinguish which one has failed, review Failure Record information and attempt to duplicate the conditions.
Important: Inaccurate readings will occur if resistance measurements are taken on a MAP sensor. The MAP sensor contains an internal amplifier circuit that requires applied voltage to function properly.
Check the PCM and MAP/TP sensors for corrosion in connectors.
Use the scan tool to monitor TP SENSOR as accelerator pedal is slowly depressed. The voltage should change smoothly from 0.4 volts at 0% throttle, to 4.7 volts at wide open throttle (+/- 0.2 volts).
LOW ALTITUDE = HIGH PRESSURE = HIGH VOLTAGE
Altitude | Voltage Range | kPa |
---|---|---|
BELOW 305 m (BELOW 1,000 ft) | 3.8-5.5 V | 98-100 kPa |
305-610 m (1,000-2,000 ft) | 3.6-5.3 V | 98-95 kPa |
610-914 m (2,000-3,000 ft) | 3.5-5.1 V | 95-92 kPa |
914-1219 m (3,000-4,000 ft) | 3.3-5 V | 92-89 kPa |
1219-1524 m (4,000-5,000 ft) | 3.2-4.8 V | 89-86 kPa |
1524-1829 m (5,000-6,000 ft) | 3-4.6 V | 86-83 kPa |
1829-2133 m (6,000-7,000 ft) | 2.9-4.5 V | 83-80 kPa |
2133-2438 m (7,000-8,000 ft) | 2.8-4.3 V | 80-77 kPa |
2438-2743 m (8,000-9,000 ft) | 2.6-4.2 V | 77-74 kPa |
2743-3948 m (9,000-10,000 ft) | 2.5-4 V | 74-71 kPa |