Test II - System Check

ISC Check. Attempt to start engine at part throttle. If engine runs only at part throttle, go to TEST X - IDLE SPEED CONTROL (BY-PASS AIR) , step 3). If engine does not run, go to next step.

MAP Check. Turn key off and disconnect MAP sensor. Connect MAP tester between harness and MAP sensor. Connect banana plugs of tester into DVOM and set DVOM on 20-volt scale. Turn key on and measure sensor voltage output while cranking engine. If DVOM reading does not decrease from specified range, go to TEST G - MAP/BP SENSOR , step 13). On 3.0L EFI engine, if DVOM reading decreases from specified range, go to TEST S - 2 .9L, 3.0L & 4.9L EFI FUEL CONTROL, step 1). On all other engines, if DVOM reading decreases from specified range, go to next step.

MAP VOLTAGE OUTPUT

Elevation (Ft.)	Voltage Output (Volts)
0	1.55-1.63
1000	1.52-1.60
2000	1.49-1.57
3000	1.46-1.54
4000	1.43-1.51
5000	1.40-1.48
6000	1.37-1.45
7000	1.35-1.43

EGR Check. Disconnect and plug vacuum hose at EGR valve. Ensure that EGR valve is closed. Attempt to start vehicle. If vehicle runs, go to:
- TEST E - EVP , EGRC & EGRV, step 8) for all 2.3L models.
- TEST I - THROTTLE POSITION SENSOR (TPS) , step 22) for 4.9L & 5.0L models.

On 2.9L engines, check exhaust gas recirculation system. If vehicle does not run, go to:

TEST R - 2 .3L EFI FUEL CONTROL, step 1) for 2.3L models.
TEST S - 2 .9L, 3.0L & 4.9L EFI FUEL CONTROL, step 1) for 2.9L, 3.0L & 4.9L models.
TEST Q - 5 .0L EFI FUEL CONTROL, step 1) for 5.0L models.