Chart A-2

If a Code EO15 is stored along with a Code EO21, the cause is probably an open in sensor ground circuit No. 976 (coolant sensor and TPS). To verify this condition, probe the following harness terminals with a voltmeter to 12 volts: coolant temperature sensor terminal "A" (Black/Pink wire) and TPS connector terminal "B" (Black/Pink wire).

If voltage is zero at both sensors, check circuit No. 976 an open. If wiring is okay, either the PCM connector or the PCM itself is faulty. If 5 volts are present at either sensor, follow the diagnostic chart each individual code. Diagnose Code EO15 first, and then Code EO21.