Diagnostic Aids

Perform this test only when directed here. This system test is intended to diagnose:

NOTE: Test procedure begins with step 10). No test procedures have been omitted.

NOTE: If a communication link error is displayed, remove jumper wire and go to step 12).

10) DTC P1115: Simulate Opposite Signal To PCM
Disconnect IAT2 sensor connector. Connect a jumper wire between IAT2 sensor harness connector IAT2 and SIG RTN terminals. Turn ignition switch to ON position. Using scan tool, select IAT2 PID from PID/DATA MONITOR & RECORD menu.
If IAT2 PID voltage is less than .2 volt, replace IAT2 sensor. If IAT2 PID voltage is .2 volt or more, remove jumper wire and go to next step.

11) Check IAT2 Sensor Signal & SIG RTN Circuits For Open

Turn ignition switch to OFF position. Disconnect PCM connector. Using a DVOM, measure resistance of IAT2 signal circuit between PCM harness connector terminal and IAT2 sensor harness connector terminal. Using a DVOM, measure resistance of IAT2 sensor SIG RTN circuit between PCM harness connector terminal and IAT2 sensor harness connector terminal. If both resistance measurements are less than 5 ohms, replace PCM. If either resistance measurement is 5 ohms or more, repair open in affected circuit.

12) Check IAT2 Sensor Signal Circuit For Short To VREF

Turn ignition switch to OFF position. Disconnect PCM connector. Using a DVOM, measure resistance between PCM harness connector VREF terminal and IAT2 sensor harness connector IAT2 signal terminal. If resistance is more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, repair short to VREF.
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 12) to step 20). No test procedures have been omitted.

20) DTC P1114: Simulate Opposite Signal To PCM

Disconnect IAT2 sensor harness connector. Connect scan tool to Data Link Connector (DLC). Turn ignition switch to ON position. Using scan tool, select IAT2 PID from PID/DATA MONITOR & RECORD menu. If IAT2 PID voltage is more than 4.2 volts, replace IAT2 sensor. If IAT2 PID voltage is 4.2 volts or less, go to next step.

21) Check VREF Voltage To TP Sensor

Turn ignition switch to OFF position. Disconnect TP sensor connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between VREF and SIG RTN terminals at TP sensor harness connector. If voltage is 4-6 volts, VREF voltage is sufficient, reconnect TP sensor connector and go to next step. If voltage is not 4-6 volts, go to TEST C, step 1).

22) Check IAT2 Sensor Signal Circuit For Short To Ground

Turn ignition switch to OFF position. Disconnect PCM connector. Using a DVOM, measure resistance between PCM harness connector IAT2 and SIG RTN terminals. Using a DVOM, measure resistance between PCM harness connector IAT2 terminal and PWR GND terminal. See PCM PWR GND, SIG RTN & VREF TERMINAL IDENTIFICATION table. See WIRING DIAGRAMS article. If both resistance measurements are more than 10 k/ohms, replace PCM. If either resistance measurement is 10 k/ohms or less, repair short to ground in affected circuit.