Manifold Absolute Pressure Sensor
2021 Toyota RAV4 · 2.5L I4
Sensor Type
piezoresistive
Waveform Type
dc-variable
Location
Mounted on intake manifold plenum top surface, passenger side near throttle body
Pins
3-pin connector
Timebase
500ms/div
Voltage Scale
1V/div
Trigger
N/A - DC signal
Wiring
Pink (5V reference from ECM), Black (ground), Blue/White (signal return to ECM)
Expected Voltage Range
At Idle
0.8V to 1.5V
At Higher RPM
4V to 4.7V
Expected Pattern
Steady DC voltage at idle indicating vacuum, approximately 1.0-1.3V; rises toward atmospheric pressure (4.5V) with throttle opening
Known-Good Waveform
At idle, MAP sensor should read 0.9-1.4V corresponding to 16-20 inHg vacuum (35-50 kPa absolute). Key-on engine-off should read approximately 4.5V reflecting atmospheric pressure (100 kPa). During snap throttle, voltage should rise smoothly to near 4.5V and return to idle vacuum level following throttle plate position with minimal lag.
Common Failure Patterns
Stuck at or near 4.5V regardless of engine vacuum condition
Cause: Ruptured sensor diaphragm, blocked vacuum port, or failed internal sensor element
Voltage reading lower than expected at idle or KOEO reading below 4.0V
Cause: 5V reference circuit fault, sensor internal failure, or wiring issue
Diagnostic Tips
The RAV4 A25A-FKS uses MAP primarily for backup and load calculation as it relies more heavily on MAF for fuel control. Verify 5V reference at sensor connector first when diagnosing. Use propane enrichment test at idle - MAP voltage should remain stable while MAF voltage increases if both sensors are functioning correctly.
Related Diagnostic Trouble Codes
P0105P0106P0107P0108P0109
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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