Test 7 Altitude Input

NOTE: Observe the following instructions when performing the Subroutine Tests.


1. Do not measure voltage or resistance at the MCU module or connect any test light to it, unless otherwise instructed to do so.

2. Turn ignition key off and isolate both ends of a circuit whenever checking for shorts or continuity.

3. Connectors shown in schematics are viewed from front of connector.

4. Disconnect solenoids and switches from harness before checking continuity, resistance or by energizing by applying battery voltage directly.

5. Follow each step in order beginning with the first one in the appropriate routine. Follow each step until the problem is located, then correct the problem and perform the appropriate Functional Test to make sure that the problem has been corrected.

Test 7-Altitude Input

1. Disconnect the altitude circuit from the engine ground (pin 18).

2. Connect ohmmeter between pin 18 and engine block ground. If reading is less than 10 ohms, repair pin 18 and/or engine ground circuit. If reading is greater than 10 ohms, go on to next step.

3. Check altitude circuit (pin 18) and engine block ground for continuity. If reading is less than 10 ohms, replace MCU module. If reading is greater than 10 ohms, repair or replace circuit.