TEST 2: Verifying MAP Sensor Has 5 Volts And Ground
If in TEST 1 the MAP sensor voltage signal is staying stuck in one number (value), then there's a good chance that it might be missing either Ground or power.
Power is in the form of 5 Volts DC and is provided by the violet with white stripe (VIO/WHT) wire. This wire is labeled with the number 3 in the photo above.
These five Volts are provided by the fuel injection computer of your Chrysler Dodge vehicle.
Ground is also provided by the fuel injection computer and is fed to the MAP sensor by the black with light blue stripe wire.
The Ground wire is identified by the wire labeled with the number 2 in the photo above.
NOTE: Ground is provided by your Chrysler or Dodge vehicle's fuel injection computer. So be careful to not apply battery power to the Ground wire or you'll fry the computer. The voltage test I'm describing below (to test for Ground) is a safe way of verifying the presence of this Ground.
These are the test steps:
- 1
Place your multimeter in Volts DC mode.
- 2
Turn the key the ON position but don't start the engine.
- 3
Disconnect the MAP sensor from its electrical connector.
- 4
Verify that the VIO/WHT wire has voltage (4.5 to 5 Volts DC) with the key on but engine off.
Connect the red multimeter test lead (using the appropriate tool) to the VIO/WHT wire. Connect the black multimeter test lead to the negative battery terminal.
Your multimeter should read 4.5 to 5 Volts DC. - 5
Verify that the BLK/LT BLU wire has Ground with the key on but engine off.
Connect the black multimeter test lead (using the appropriate tool) to the BLK/LT BLU wire. Connect the red multimeter test lead to the positive battery terminal.
Your multimeter should read 10 to 12 Volts DC.
Let's analyze your test results:
CASE 1: 5 Volts and Ground are present. This is the correct test result.
You can correctly conclude that the MAP sensor is defective if you have:
- Verified that its MAP voltage signal does not decrease/increase as you apply/release vacuum to the MAP sensor.
- Verified it's getting both 5 Volts and Ground.
Check my MAP sensor recommendations here: Where To Buy The MAP Sensor And Save.
CASE 2: 5 Volts are not present. Without these 5 Volts the MAP sensor will not function.
Although it's beyond the scope of this tutorial to troubleshoot these missing 5 Volts, the most likely cause is an open-circuit problem in the wire between the MAP sensor's connector and the fuel injection computer's connector.
CASE 3: Ground is not present. Without Ground the MAP sensor will not function.
Although it's beyond the scope of this tutorial to troubleshoot this missing Ground, the most likely cause is an open-circuit problem in the wire between the MAP sensor's connector and the fuel injection computer's connector.
More 2.4L Chrysler And Dodge Tutorials
You can find a complete list of 2.4L Chrysler and Dodge tutorials in this index:
Here's a small sample of the tutorials you'll find in the index:
- How To Test Engine Compression (2.4L Chrysler, Dodge, Plymouth).
- How To Test For A Blown Head Gasket (2.4L Chrysler, Dodge, Plymouth).
- Ignition System Wiring Diagram (1995-1998 2.4L Cirrus, Stratus, Breeze).
- Fuel Injector Circuit Wiring Diagram (1995-2000 2.4L Cirrus, Stratus, Breeze).
If this info saved the day, buy me a beer!
