Form PCM from breakout box. Get PCM to breakout box. Best key to RUN. To now the wiring more trace it through the academy harness and back to the PCM.
Disconnect PCM from breakout box. Measure resistance between test pin No. If resistance is less than 5 Ford escort codes, replace PCM. If resistance is 5 ohms or more, repair open circuit. Install breakout box, leaving PCM disconnected. Disconnect suspect HO2S connector. Inspect connectors for loose, damaged or corroded terminals. If all resistance readings are less than 5 ohms, go to next step. If any resistance reading is 5 ohms or more, repair open circuit. If all resistance readings are more than 10, ohms, go to next step. If any resistance reading is 10, ohms or less, repair short circuit. Measure resistance between test pins No. If any resistance reading is 10, ohms or less, replace HO2S.
If all resistance readings are more than 10, ohms, replace PCM. If PID voltage is more than. If PID voltage is. Disconnect scan tool from DLC. Measure resistance between the following test pins at breakout box: If any resistance reading is 10, ohms or less, repair short to power. With ignition off, install fuel pressure gauge. Command fuel pump on. If fuel system pressure is as specified, go to step The Purge Valve The purge valve is located in-line between the canister and the intake manifold. Remove the purge valve and inspect it. The purge valve may be mechanically stuck from some type of blockage. This would prevent pressure from flowing between the canister and the engine. It may also be stuck open preventing pressure from building up, causing a low flow of pressure when the PCM tries to purge the canister.
If the purge valve is stuck open, or the diaphragm is seized, replace the purge valve and clear the trouble codes, you problem will likely be solved. Other Concepts Rumor has it code P can be set by a leaking or improperly tightened gas cap, but this is almost never the case.
There could also be a fault in the circuit between the purge control valve and the PCM, preventing the valve from opening and setting trouble code P There are 2 plugs Ford escort codes find. One is triangular and has 6 pins; it is called the Self-Test plug. These are what the plugs look like. I am not sure if it is in the same location for pre Escorts, but I should think it would be the same. How to Prepare for the Self-Test To check for codes without buying a code reader is simple. If your EEC is wired correctly, the engine light works, and there are not any electrical faults in the vehicle you can get the codes out of your EEC.
Turn key to OFF.
OBD2 connector location - Ford Escort (1995 - 2000)
Get a length of wire that can connect the STI to the negative battery terminal or body ground. Ground the Self-Test Input. Get some paper and a pen.