Test KQ: Thermostat Heater Control: Testing
NOTE:
Procedure starts from step 10). No test procedures have been omitted.
- 10) KOEO, KOER & Continuous Memory DTC P1432: Check VPWR To THTRC Harness Connector
DTC P1432 is set when PCM detects THTRC circuit voltage below a calibrated limit for a calibrated time during Comprehensive Component Monitor (CCM). Possible causes are:- THTRC Circuit Open Or Shorted To B+, GND Or VPWR
- VPWR Circuit Open
- Open Or Shorted Thermostat Assembly
- Faulty PCM
Turn ignition switch to OFF position. Disconnect THTRC connector. Turn ignition switch to ON position. Using a DVOM, measure voltage between chassis ground and VPWR circuit (Light Blue/Orange wire) at THTRC harness connector. If voltage is more than 10.5 volts, go to next step. If voltage is 10.5 volts or less, repair open in Light Blue/Orange wire between THTRC and splice No. 153 at engine.
- 11) Check THTRC Resistance
Turn ignition switch to OFF position. Using a DVOM, measure resistance between THTRC connector terminals. Resistance should be 14-16 ohms. If resistance is within specification, go to next step. If resistance is not within specification, replace THTRC. - 12) Check THTRC Circuit For Open In Harness
Ensure ignition switch is turned to OFF position. Disconnect PCM connector. Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance of THTRC circuit (Dark Blue wire) between THTRC harness connector and PCM harness connector. 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 THTRC circuit. - 13) Check THTRC Circuit For Short To GND Or VPWR In Harness
Using a DVOM, measure resistance between THTRC circuit, and SIG RTN, PWR GND and VPWR circuits at PCM harness connector. If all resistance measurements are more than 10 k/ohms, go to TEST Z, step 1) (for Continuous Memory DTC P1432), or replace PCM (for KOEO or KOER DTC P1432). If any resistance measurement is 10 k/ohms or less, repair THTRC circuit for short to GND, SIG RTN or VPWR circuit.
NOTE:
For additional testing information, see DIAGNOSTIC AIDS .