Signal Too Low. Intermittent Fault

Signal too low. Intermittent fault

Checking wiring
Check the engine control module (ECM) and mass air flow (MAF) sensor connectors. Check for contact resistance and oxidation according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults.
Check in particular for damage or loose terminal pins.
Check the signal cable between engine control module (ECM) terminal #16 and mass air flow (MAF) sensor terminal #2. Check for an intermittent short-circuit to ground. according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults. Remedy if necessary.
Check the power supply cable between mass air flow (MAF) sensor terminal #3 and system relay (2/14) terminal #3. Check for an intermittent open-circuit according to Checking wiring and terminals. Intermittent faults Checking Wiring And Terminals. Intermittent Faults. Remedy if necessary.
The supply voltage should be approximately battery voltage when the system relay is activated.
Check that the idling system air ducts are not blocked.

Hint: If there is a mechanical defect in the idle air control (IAC) valve the air flow may be hindered by blockages in the idling system air ducts.

Check the intake system for air leakage according to intake system/leak test Intake System/Leak Test.

Other information:
- To connect the breakout box, see Connecting the breakout box. EMS 2000 Connecting The Breakout Box. EMS 2000
- To replace the mass air flow (MAF) sensor, see Replacing the mass air flow (MAF) sensor Service and Repair
- To replace the idle air control (IAC) valve, see Replacing the idle air control (IAC) valve Service and Repair.













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Continue - Fault-tracing information

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Fault-tracing information




Information

Fault-tracing information
If the fault is intermittent, do not verify fault-tracing if the fault does not recur.
It is possible to view the information again, or leave fault-tracing for this diagnostic trouble code (DTC).

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Yes - Attempt New Test

No - FAULT FOUND

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Attempt New Test - Checking wiring

FAULT FOUND - DONE

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