Test KP: Charge Air Cooler Pump: Testing

WARNING: This page does not describe the selected car, but rather 25 other vehicles, including the 2002 Lincoln Town Car, 2002 Lincoln Navigator, 2002 Lincoln LS, 2002 Lincoln Continental, and 2002 Lincoln Blackwood. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

1) DTC P1229: Check VPWR To CAC Pump Relay Coil
DTC P1229 is set when PCM is requesting CAC pump motor to operate, but voltage is not detected on CAC circuit. Possible causes are:
- Internal Open In CAC Pump Motor
- B+ Or VPWR Circuit Open Or Shorted To Ground
- CAC Or CAC PUMP PWR Circuit Open Or Shorted To Ground
- Faulty CAC Pump Relay
- CAC Pump Motor Shorted
- Bad CAC Pump Motor Ground Connection
- Faulty PCM
Turn ignition switch to OFF position. Check fuse No. 23 (15-amp) located in battery junction box in engine compartment. If fuse is okay, go to next step. If fuse is blown, check VPWR circuit (Red/Yellow wire) between fuse No. 23 and CAC pump relay for short to ground. Repair as necessary. Replace blown fuse.

2) Check B+ Voltage Supply To CAC Pump Relay

Ensure ignition switch is turned to OFF position. Check fuse No. 106 (20-amp) located in battery junction box in engine compartment. If fuse is okay, go to next step. If fuse is blown, check B+ circuit (Orange/Yellow wire) between fuse No. 106 and CAC pump relay, or CAC PUMP PWR circuit (White wire) between CAC pump relay, and CAC pump motor for short to ground. Repair as necessary and replace fuse.

3) Check CAC Pump Motor Ground Circuit

Disconnect CAC pump motor connector. Using a DVOM, measure resistance between negative battery terminal and CHASSIS GROUND circuit (Black wire) at CAC pump motor harness connector. See Figure. If resistance is less than 2 ohms, go to next step. If resistance is 2 ohms or more, check tightness of ground lug G104, located behind left side headlight near radiator support. If ground lug is okay, check for open in Black wire to CAC pump motor.

4) Check CAC Pump Motor Resistance

Using a DVOM, measure resistance between both CAC pump motor terminals. If resistance is less than 10 ohms, go to next step. If resistance is 10 ohms or more, replace CAC pump motor.

5) Check CAC Pump Relay

Remove CAC pump relay from battery junction box in engine compartment. Using a DVOM, measure resistance between relay terminals No. 1 and 2. Resistance should be 65-90 ohms. Measure resistance between relay terminal No. 1 and all other relay terminals. Resistance should be more than 10 k/ohms. See Figure and Figure . If resistance is as specified, go to next step. If resistance is not as specified, replace CAC relay.

6) Check For Open CAC Circuit Between PCM & CAC Relay

Ensure ignition switch is in OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of CAC circuit (White/Orange wire) between PCM harness connector and CAC pump relay cavity. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in CAC circuit.

7) Check CAC Circuit Between PCM & CAC Pump Relay For Short To Ground

Using a DVOM, measure resistance between negative battery terminal and CAC circuit (White/Orange wire) at PCM harness connector. See Figure and Figure . If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in CAC circuit.

8) Check CAC Circuit Between PCM & CAC Pump Relay For Short To PWR

Ensure CAC relay is removed from battery junction box in engine compartment. Turn ignition switch to ON position. Using a DVOM, measure voltage between negative battery terminal and CAC circuit at PCM harness connector. If voltage is less than .05 volt, go to next step. If voltage is .05 volt or more, repair short to B+ or VPWR in CAC circuit.

9) Check For Open Circuit Between PWR Feed & CAC Pump Relay

Turn ignition switch to OFF position. Ensure fuse No. 23 (15-amp) and CAC pump relay are removed from battery junction box in engine compartment. Using a DVOM, measure resistance of VPWR circuit (Red/Yellow wire) between CAC pump relay cavity No. 1 and output side of fuse No. 23. See Figure. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in VPWR circuit to CAC pump relay.

10) Check For Open PWR Feed Circuit At CAC Pump Relay

Ensure ignition switch is turned to OFF position. Ensure fuse No. 106 is removed from battery junction box in engine compartment. Using a DVOM, measure resistance of B+ circuit (Orange/Yellow wire) between CAC pump relay cavity No. 3 and output side of fuse No. 106. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in B+ circuit to CAC pump relay .

11) Check For Open CAC PUMP PWR Circuit Between CAC Pump Relay & CAC Pump

Using a DVOM, measure resistance of CAC PUMP PWR circuit (White wire) between CAC pump relay cavity No. 5 and CAC pump harness connector. See Figure & Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in CAC PUMP PWR circuit to CAC pump.

NOTE: On some scan tools, SCICP PID may indicate ICP PID.

12) Check Status Of SCICP PID
Ensure ignition switch is turned to OFF position. Reconnect PCM connector. Reinstall CAC relay and fuses No. 23 and 106. Turn ignition switch to ON position. Using scan tool, access SCICP PID from PID/DATA MONITOR & RECORD menu. If SCICP PID value indicates OFF, check for intermittent faults. Go to TEST Z, step 1). If SCICP PID value indicates ON, proceed as follows:
- Check CAC reservoir level.
- Check for air flow blockage at CAC radiator.
- Check for high resistance or open circuit in Intake Air Temperature (IAT) 2 sensor and connecting circuits.
- Check for reversed intercooler hoses.
Repair as necessary. If no concerns are found and DTC P1229 is present in KOEO and KOER self-test, replace PCM.