Signal Too Low

ECM-1400 MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
SIGNAL TOO LOW

DTC status ECM-1400 Manifold absolute pressure (MAP) sensor. Signal too low
Reading of DTC status ECM-1400





Note! When Reading the DTC status, other stored Diagnostic Trouble Codes (DTCs) and their status will be listed.

- Read the 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 connector



- Ignition off.
- Check manifold absolute pressure (MAP) sensor connector for contact resistance and oxidation according to [1][2]Checking Wiring and Terminals. Permanent Fault

Remedy as necessary.

Other information
- For information about signals, Pinout Values and Diagnostic Parameters
- To localize the manifold absolute pressure (MAP) sensor, Locations


Checking manifold absolute pressure (MAP) sensor signal



- Ignition off.
- Reinstall components, reconnect connectors etc.
- Ignition on.
- Read the manifold absolute pressure (MAP) sensor signal.

Check that the signal is within its permitted range. The manifold absolute pressure (MAP) sensor voltage is compared to the table value: Manifold Absolute Pressure (MAP) Sensor

If signal is now OK this indicates that the fault was caused by poor contact in the connector.

Other information
- For information about signals, Pinout Values and Diagnostic Parameters
- To localize the manifold absolute pressure (MAP) sensor, Locations

Is the signal OK?
Yes - Skip to "Verification"
No - Continue below.


Checking wiring and components



Check reference voltage cable between control module connector # A58 (# A60) and manifold absolute pressure (MAP) sensor connector terminal 3 for an open-circuit according to [1][2]Checking Wiring and Terminals. Permanent Fault and a short-circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault

Hint: With the ignition on and manifold absolute pressure (MAP) sensor connector disconnected the voltage between terminal 3 and ground terminal should be approximately 5V.

Check signal cable between control module connector # A23 (# A23) and manifold absolute pressure (MAP) sensor connector terminal 1 for a short-circuit to ground according to [1][2]Checking Wiring and Terminals. Permanent Fault

Hint: With the ignition on and manifold absolute pressure (MAP) sensor connector disconnected the voltage between terminal 1 and ground terminal should be approximately 5V.

If wiring is OK, try a new manifold absolute pressure (MAP) sensor.

Remedy as necessary.

Other information:
- To connect the breakout box, Connecting the Breakout Box (ECM)
- To access/replace the control module, Engine Control Module (ECM), Replacing
- For information about signals, Pinout Values and Diagnostic Parameters
- To localize the manifold absolute pressure (MAP) sensor, Locations


Verification



Hint: After carrying out the repair, check that the fault has been remedied.
- Ignition off.
- Reconnect connectors, reinstall components.
- Ignition on.
- Read the manifold absolute pressure (MAP) sensor signal.
- Start the engine. Check that the signal varies (sinks) during acceleration.

Check that the signal is within its permitted range. The manifold absolute pressure (MAP) sensor voltage is compared to the table value. Manifold Absolute Pressure (MAP) Sensor

Check that the signal is OK.

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.