Test Procedure
WARNING: This page is about a different car, the 2007 Mercury Mariner and 2007 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
- QB1 DIAGNOSTIC TROUBLE CODES (DTCS) P0603 AND P1633: CHECK THE 12 VOLT BATTERY TERMINALS NOTE: If KAPWR is interrupted to the PCM because of a battery or PCM disconnect, a DTC can be generated on the first power-up.
- Inspect the 12 volt battery cables for loose connections and for corrosion.
- Are the 12 volt battery terminal connections in good condition?
Yes No GO to QB2. REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test. - QB2 CHECK KAPWR TO THE PCM
- Key in OFF position.
- PCM connector disconnected.
- Measure the voltage between:
( + ) PCM Connector, Harness Side ( - ) Vehicle Battery KAPWR - Pin B45 Negative terminal - Is the voltage less than 10.5 V?
Yes No REPAIR the circuit.
CLEAR the DTCs. REPEAT the self-test.GO to QB3. - QB3 CHECK FOR A REPEAT OF THE DTC
- PCM connector connected.
- Clear all DTCs that may have been caused by the PCM disconnect.
- Test drive the vehicle and allow the engine to reach normal operating temperature.
- Check for self-test DTCs.
- Are DTCs P0603 or P1633 present?
Yes No GO to QB4. Unable to duplicate or identify the concern at this time.
refer to PINPOINT TEST Z . - QB4 INSPECT THE ENGINE COMPARTMENT FOR CORRECT WIRE ROUTING
- Inspect the electronic engine control (EEC) system wiring for correct wire routing.
- Check the wiring routing to establish if any of the electrical connectors are being stressed due to poorly routed wiring. If necessary re-route and secure the wiring.
- Visually inspect wiring and connectors.
- Are any concerns present?
Yes No REPAIR as necessary.
CLEAR the DTCs. REPEAT the self-test.GO to QB5. - QB5 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Visually inspect for:
- pushed out pins
- corrosion
- Connect all the PCM connectors and make sure they seat correctly.
- Carry out the PCM self-test and verify the concern is still present.
- Is the concern still present?
Yes No INSTALL a new PCM. REFER toFLASH ELECTRICALLY ERASABLE PROGRAMMABLE READ ONLY MEMORY (EEPROM) . The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.