Chart A2

If code EO15 is stored hard, along with code EO21 or EO26, the cause is probably an open in sensor ground circuit No. 476 for the coolant sensor and TPS. To verify, probe the following harness terminals with a voltmeter to 12 volts: coolant temperature sensor pin "A" (Black/Pink wire). TPS connector pin "B" (Black/Pink wire).

If voltage is zero at both sensors, check circuit No. 476A for an open. If wiring is okay, either the ECM connector or the ECM itself is faulty. If 12 volts is present at either of the sensor, follow the diagnostic chart for each individual code. Diagnose code EO15 first, code EO21 second, and code EO26 last.