P050A-COLD START IDLE AIR CONTROL SYSTEM PERFORMANCE

For a complete wiring diagram Refer to Section 8W.

When Monitored:
Cold start condition. Ambient Air temperature between -7°C and 50 °C (19.4°F and 122°F). Engine Coolant temperature between -7°C and 50 °C (19.4°F and 122°F). The difference between the Ambient Air temp and ECT temp at Start is equal to or less than 10°C (50°F). Engine running at idle only.
Set Condition:
If the ratio of air flow between Total Port Mass Flow and the In Man Mass Flow is below a calibratable threshold and difference between Linear IAC Current and Sensed IAC Current is below a calibratable threshold P050A will set. Two Trip Fault. Three good trips to turn off the MIL.

Possible Causes

RESTRICTED INTAKE AIR SYSTEM

EXCESSIVE RESISTANCE IN THE (K61) IAC CONTROL CIRCUIT

EXCESSIVE RESISTANCE IN THE (K961) IAC SIGNAL CIRCUIT

IAC/THROTTLE BODY

PCM

Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. (Refer to 9 - ENGINE - DIAGNOSIS AND TESTING).

Diagnostic Test

1.ACTIVE DTC

NOTE: Low battery voltage can also cause excessive current draw, in very hot and very cold ambient temperatures. Make sure the battery can pass a load test before continuing.

NOTE: It may be necessary to drive the vehicle to meet the conditions to set this DTC, try to repeat the conditions in which the fault originally set by reviewing the Freeze Frame data.

Is the DTC Active or Pending at this time?

Yes

Go To 2

Refer to the INTERMITTENT CONDITION Diagnostic Procedure.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

2.THROTTLE PLATE INSPECTION

Were any signs of foreign material or scoring of the throttle plate or bore found?

Yes

Remove the debris if possible or replace the Throttle Body Assembly as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 3

3.DIRTY AIR FILTER

Is the Air Filter dirty?

Yes

Replace the Air Filter.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Go To 4

4.EXCESSIVE RESISTANCE IN THE (K961) IAC SIGNAL CIRCUIT

CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 along with the #8815-1 to perform the diagnosis.

WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.

Is the voltage below 0.5 of a volt?

Yes

Go To 5

Repair the excessive resistance in the (K961) IAC Signal circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

5.EXCESSIVE RESISTANCE IN THE (K61) IAC CONTROL CIRCUIT

Is the voltage below 0.5 of a volt?

Yes

Go To 6

Repair the excessive resistance in the (K61) IAC Control circuit.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

6.IAC MOTOR

NOTE: Inspect the IAC air passages for restrictions and damage to the IAC valve and clean as necessary.

Is the resistance 9.7 +/- 1.0 ohms?

Yes

Go To 7

Replace the IAC Motor.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

7.PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Were there any problems found?

Yes

Repair as necessary.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)

Replace and program the Powertrain Control Module per Service Information.
Perform the POWERTRAIN VERIFICATION TEST. (Refer to 9 - ENGINE - STANDARD PROCEDURE)