Signal Too Low

ECM-5000 AIR CONDITIONING (A/C) PRESSURE SENSOR
SIGNAL TOO LOW

Reading Diagnostic trouble code (DTC) status ECM-5000:



Note! When Reading the Diagnostic trouble code (DTC) status, other stored diagnostic trouble codes (DTCs) and their status will be listed.

- Read diagnostic trouble code (DTC) status. Check the status of the relevant Diagnostic Trouble Code (DTC).

Was the status of the relevant Diagnostic Trouble Code (DTC) displayed as permanent?
Yes - Continue below.
No - Signal Too Low - Intermittent Fault


Checking wiring and components



Check air conditioning (A/C) pressure sensor resistance.

Check signal cable between control module # A21 (# A21) and mass air flow (MAF) sensor terminal 2 for a short-circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault

Hint: With the ignition on and air conditioning (A/C) pressure sensor connector disconnected the voltage between terminal 3 and ground terminal should be approximately 5 V.

Remedy as necessary.

Other information:
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace air conditioning (A/C) pressure sensor, Pressure Switch/Pressostat, Replacing
- For information about signals, Pinout Values and Diagnostic Parameters


Verification



Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reconnect connectors, reinstall components
- Ignition on.
- Read air conditioning (A/C) pressure sensor signal.

The signal should be between 0.7 - 0.9 V.

Is the signal OK?
Yes - Testing Complete.
No - Continue below.


Fault-tracing information
The fault should have been detected and remedied. As this is not the case fault-tracing has failed.
Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.