Test R - PSPS
To prevent replacement of good components, be aware that the following non-EEC related areas may be at fault: idle speed/throttle stop adjustment, binding throttle shaft/linkage or cruise control linkage.
- Code 52 Displayed. Turn key off and wait 10 seconds. Disconnect PSPS. Install a jumper wire between PSPS circuit and signal return at harness. Repeat KEY ON/ENGINE OFF (KOEO) SELF-TEST. If code 52 is not displayed, replace PSPS and repeat QUICK TEST . If code 52 is still displayed, go to next step.
- Turn key off and wait 10 seconds. Disconnect PSPS and ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM on 200-ohm scale and measure resistance between test pin No. 46 and signal return at PSPS connector. Also measure resistance between PSPS harness connector and test pin No. 23. If both readings are less than 5 ohms, replace ECA. Repeat QUICK TEST . If readings are greater than 5 ohms, repair open in circuit. Repeat QUICK TEST .
- Connect tachometer and start engine. Allow engine to idle in Park or Neutral. Disconnect PSPS at switch. If RPM increases, replace PSPS. If RPM does not increase, go to next step.
- Turn key off and wait 10 seconds. Disconnect PSPS and ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM on 200,000-ohm scale. Measure resistance between test pin No. 46 and test pin No. 23. If reading is 10,000 ohms or less, repair short in harness. If reading is greater than 10,000 ohms, replace ECA. Repeat QUICK TEST .
- KEY ON/ENGINE RUNNING (KOER) Self-Test Code 52 Displayed. If you turned steering wheel 1/2 turn any time AFTER engine ID code, but BEFORE dynamic response code, go to next step. If steering wheel was not turned, make sure front wheels are centered (no load condition). Repeat QUICK TEST .
- Turn key off and wait 10 seconds. Disconnect PSPS. Perform KOEO SELF-TEST. If code 52 is present, go to step 8). If code 52 is not present, go to next step.
- Turn key off and wait 10 seconds. Disconnect PSPS and ECA 60-pin connector. Inspect connector for damaged pins, corrosion, or loose wires. Install breakout box and set DVOM on 200,000-ohm scale. Measure resistance between test pins No. 46 and 24 at breakout box. If reading is 10,000 ohms or less, repair short to signal return in PSPS circuit. Repeat QUICK TEST . If reading is 10,000 ohms or more, replace ECA and repeat QUICK TEST .
- Turn key off and wait 10 seconds. Install breakout box, leaving ECA connected. With PSPS connected, set DVOM on 200-ohm scale. Turn key on and measure resistance between test pins No. 24 and 46. Start engine. If reading remains less than 10 ohms with engine off or engine running, go to next step. If not, go to step 11).
- Install breakout box and connect ECA. Connect PSPS and set DVOM on 200-ohm scale. Start engine and allow it to idle. Measure hesitance between test pins No. 24 and 46 on breakout box. Turn steering wheel 1/2 turn and then return. If reading changes from less than 10 ohms to infinity (indicating PSPS opening) and then returns to 10 ohms or less, PSPS system is okay. Remove breakout box and return to QUICK TEST . If reading did not change as indicated, go to next step.
- At this point, there are only 2 possible causes for code 52. They are a PSPS switch that will not open, or low available hydraulic pressure. Turn key off and wait 10 seconds. Substitute original switch with a known good PSPS switch. Perform KOER SELF-TEST and turn steering wheel 1/2 turn during test. If code 52 is still present, check for low hydraulic pressure. If code 52 is not present, replace original PSPS switch. Service other codes if necessary.
- At this point, there are only 2 possible causes for code 52. They are a PSPS switch that is always open, or excessively high hydraulic pressure. Turn key off and wait 10 seconds. Substitute original switch with a known good PSPS switch. Perform KOER SELF-TEST and turn steering wheel 1/2 turn during test. If code 52 is still present, check for high hydraulic pressure. If code 52 is not present, replace original PSPS switch. Service other codes if necessary.