Test Di: Manifold Air Temperature Sensor (Except ECONOLINE): Testing

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NOTE: Proceed to DTC testing steps listed in FAULT CODE SETTING CONDITION table of fault code setting condition.

FAULT CODE SETTING CONDITION

Fault Code	KOEO	KOER	Continuous Memory
P1118	DI1		DI1
P1119	DI1		DI1

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

1) DTC P1119: MAT Sensor Circuit High Input
DTC P1119 indicates that MAT sensor signal voltage is more than self-test maximum. The following are possible causes for this fault:
- Open SIG RTN Circuit
- Faulty MAT Sensor Or Connector
- Faulty PCM
Disconnect MAT sensor connector. MAT sensor is located at center front of engine. MAT sensor 2-pin connector has Red/Yellow and Gray/Red wires. Using DVOM, measure resistance between chassis ground and MAT sensor harness connector terminal No. 1 (Gray/Red wire). See Figure. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Gray/Red wire between PCM and MAT sensor.

2) Induce Opposite Failure

Turn ignition on. Connect a jumper wire between MAT sensor harness connector terminals. Perform KOEO ON-DEMAND SELF-TEST under QUICK TEST. If DTC P1118 is not present, go to next step. If DTC P1118 is present, replace MAT sensor. Clear DTCs and retest.

3) Check MAT Signal Circuit

Turn ignition off. Disconnect PCM connector and inspect for damaged pins, corrosion and loose wires. PCM is located in left rear of engine compartment, near brake master cylinder. Repair connector as necessary. Install Rotunda Breakout Box (014-00950), leaving PCM disconnected. Using DVOM, measure resistance between test pin No. 62 at breakout box and MAT sensor harness connector terminal No. 2 (Red/Yellow wire). If resistance is less than 5 ohms, go to step 6). If resistance is 5 ohms or more, repair open in Red/Yellow wire between PCM and MAT sensor. Clear DTCs and retest.

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

4) KOEO & Continuous Memory Only DTC P1118: Induce Opposite DTC P1119
DTC P1118 indicates that Manifold Air Temperature (MAT) sensor signal voltage is less than self-test maximum. MAT sensor may also be referred to as Air Charge Temperature (ACT) sensor. The following are possible causes for this fault:
- MAT Signal Circuit Shorted To Ground
- MAT SIG RTN Circuit Open
- Faulty MAT Sensor
- Faulty Powertrain Control Module (PCM)
Disconnect MAT sensor connector. MAT sensor is located at center front of engine and has a 2-pin connector with Red/Yellow and Gray/Red wires. Perform KOEO ON-DEMAND SELF-TEST under QUICK TEST. If DTC P1119 is not present, go to next step. If DTC P1119 is present, replace MAT sensor. Clear DTCs and retest.

5) Check MAT Sensor Signal For Short To Ground

Turn ignition off. Disconnect PCM connector and inspect for damaged pins, corrosion and loose wires. PCM is located in left rear of engine compartment, near brake master cylinder. Repair connector as necessary. Install Rotunda Breakout Box (014-00950), leaving PCM disconnected. Using DVOM, measure resistance between test pin No. 62 and test pins No. 51, 76, 77, 91 and 103 at breakout box. If each resistance is more than 10 k/ohms, replace PCM. Clear DTCs and retest. If any resistance is 10 k/ohms or less, locate and repair short to ground in MAT signal circuit (Red/Yellow wire) between PCM and MAT sensor. Clear DTCs and retest.

6) Check SIG RTN Circuit For Open

Using DVOM, measure resistance of SIG RTN circuit (Gray/Red wire) between MAT sensor harness connector terminal No. 1 and test pin No. 91 at breakout box. If resistance is less than 5 ohms, replace PCM. Clear DTCs and retest. If resistance is 5 ohms or more, repair open in Gray/Red wire between PCM and MAT sensor. Clear DTCs and retest.